Three New Volcanos Erupting This Week~~ 19 Total Active

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m

CVGHM reported that seismicity from Karangetang increased during 30-31
May and tremor was detected. On 30 May, diffuse white plumes rose
10-50 m high and incandescence was seen at the crater. On 31 May,
white emissions from Utama Crater in the N part of the summit region
rose 100 m. Incandescent material traveled as far as 2.3 km, mostly
down the S flank. Ash plumes that rose 25-700 m were accompanied by
thunderous sounds. The Alert Level was raised to 4, the highest level
on a scale of 1-4. People were advised not to go within a 3-km-radius
of the active area. According to a news article, over 350 people
evacuated the area.

Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi, and contains five
summit craters strung along a N-S line. One of Indonesia's most active
volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Sources: Center of Volcanology and Geological Hazard Mitigation
(CVGHM), Xinhua

Karangetang [Api Siau] Information from the Global Volcanism Program

MAKIAN Halmahera 0.32°N, 127.40°E; summit elev. 1357 m

CVGHM reported that during 28 May-2 June seismicity from Makian
increased, particularly the occurrence of tremor. Little, if any,
increases in emissions were seen. The Alert level was raised to 2 (on
a scale of 1-4).

Geologic Summary. Makian volcano forms a 10-km-wide island near the
southern end of a chain of volcanic islands off the W coast of
Halmahera and has been the source of infrequent, but violent eruptions
that have devastated villages on the island. The large 1.5-km-wide
summit crater, containing a small lake on the NE side, gives the peak
a flat-topped profile. Two prominent valleys extend to the coast from
the summit crater on the N and E sides. Four parasitic cones are found
on the western flanks. Eruption have been recorded since about 1550;
major eruptions in 1646, 1760-61, 1861-62, 1890, and 1988 caused
extensive damage and many fatalities.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Makian Information from the Global Volcanism Program

SLAMET Central Java (Indonesia) 7.242°S, 109.208°E; summit elev. 3428
m

Based on ground information from CVGHM, the Darwin VAAC reported that
on 27 May an ash plume from Slamet rose to an altitude of 4.3 km
(14,000 ft) a.s.l. Analysis of satellite imagery indicated that a
possible plume rose to an altitude of 6.1 km (20,000 ft) a.s.l., but
ash was not conclusively detected.

Geologic Summary. Slamet, Java's second highest volcano at 3428 m and
one of its most active, has a cluster of about three dozen cinder
cones on its lower SE-NE flanks and a single cinder cone on the
western flank. Slamet is composed of two overlapping edifices, an
older basaltic-andesite to andesitic volcano on the west and a younger
basaltic to basaltic-andesite one on the east. Gunung Malang II cinder
cone on the upper eastern flank on the younger edifice fed a lava flow
that extends 6 km to the east. Four craters occur at the summit of
Gunung Slamet, with activity migrating to the SW over time. Historical
eruptions, recorded since the 18th century, have originated from a 150-
m-deep, 450-m-wide, steep-walled crater at the western part of the
summit and have consisted of explosive eruptions generally lasting a
few days to a few weeks.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Slamet Information from the Global Volcanism Program

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Jun 10, 2009, 5:39:42 PM6/10/09

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SI / USGS Weekly Volcanic Activity Report

3 June-9 June 2009

New Activity/Unrest:

| Galeras, Colombia

| Karangetang [Api Siau], Siau I

| Sangeang Api, Lesser Sunda Islands (Indonesia)
| Slamet, Central Java (Indonesia)

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile
| Dukono, Halmahera

| Fuego, Guatemala
| Karymsky, Eastern Kamchatka
| Kelut, Eastern Java (Indonesia)

| Kilauea, Hawaii (USA)
| Llaima, Central Chile

| Manam, Northeast of New Guinea (SW Pacific)
| Pacaya, Guatemala

| Popocatépetl, México
| Rabaul, New Britain
| Redoubt, Southwestern Alaska
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)
| Tungurahua, Ecuador
| Ubinas, Perú

This page is updated on Wednesdays, please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between

the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

INGEOMINAS reported that an eruption of Galeras on 7 June was preceded
by a M 4 earthquake located about 3 km SSE of the crater at a depth of
2 km, and felt by nearby residents. The eruption produced an ash plume
that rose to an altitude of 6.8 km (22,300 ft) a.s.l. and drifted NW.
Vibrations from an accompanying acoustic wave were detected by
residents. Ashfall was reported in areas downwind. The Alert Level was
raised to I (Red; "imminent eruption or in progress"). On 8 June, two
explosions about 5 minutes apart were heard by people up to 45 km
away. The event was preceded by an M 3.9 earthquake located 1 km E at
a depth near 2 km. Ashfall was reported in areas to the NW, up to 180
km away. Based on analysis of satellite imagery, the Washington VAAC
reported that the ash plume rose to an altitude of 10 km (33,000 ft)
a.s.l. and drifted NW. They also reported that a second and larger
eruption produced an ash plume that rose to an altitude of 13.7 km
(45,000 ft) a.s.l. and drifted SE. On 9 June, INGEOMINAS reported that
seismicity and sulfur dioxide output were low, and that clear
conditions revealed no emissions.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),
Washington Volcanic Ash Advisory Center (VAAC)

Galeras Information from the Global Volcanism Program

KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m

CVGHM reported that during 1-6 June lava flows from Karangetang
traveled 50 m E and 600 m SE. Incandescent rocks, from the main
craters and ends of the lava flows, traveled as far as 2 km towards
multiple river valleys, including the Keting River to the S. On 1
June, white-to-gray-to-brownish plumes rose 700 m above the main
crater. Incandescent lava was ejected 500-700 m. On 4 June, tremor
amplitude and the number of earthquakes decreased. During 4-6 June,
white plumes rose 50-300 m from the main crater. On 7 and 8 June, fog
often prevented observations and incandescent rocks were rarely seen.
The Alert Level was lowered to 3 (on a scale of 1-4) on 9 June.

Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi, and contains five
summit craters strung along a N-S line. One of Indonesia's most active
volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Karangetang [Api Siau] Information from the Global Volcanism Program

SANGEANG API Lesser Sunda Islands (Indonesia) 8.20°S, 119.07°E; summit
elev. 1949 m

CVGHM reported that on 4 June the Alert Level for Sangeang Api was
raised to 2 (on a scale of 1-4) due to recent increases in the number
of earthquakes. White plumes rose 5-25 m during 1 May-3 June.

Geologic Summary. Sangeang Api volcano, one of the most active in the
Lesser Sunda Islands, forms a small 13-km-wide island off the NE coast
of Sumbawa Island. Two large trachybasaltic-to-tranchyandesitic
volcanic cones, 1949-m-high Doro Api and 1795-m-high Doro Mantoi, were
constructed in the center and on the eastern rim, respectively, of an
older, largely obscured caldera. Flank vents occur on the south side
of Doro Mantoi and near the northern coast. Intermittent historical
eruptions have been recorded since 1512.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Sangeang Api Information from the Global Volcanism Program

SLAMET Central Java (Indonesia) 7.242°S, 109.208°E; summit elev. 3428
m

CVGHM reported that during 26 May-4 June activity from Slamet
fluctuated, but decreased overall. The number of earthquakes and the
temperature of water in areas around the volcano were lower. Inflation
and deflation fluctuated within a range of 2 cm. White plumes rose
100-750 high. During 5-7 June, activity was characterized by inflation
and an increased number of earthquakes. During that time, white plumes
were accompanied by ash emissions that rose 200-800 m from the crater,
incandescent material was ejected 50-200 m above the crater, and
booming noises were reported. The Alert Level remained at 3 (on a
scale of 1-4).

Geologic Summary. Slamet, Java's second highest volcano at 3428 m and

one of its most active, has a cluster of about three dozen cinder
cones on its lower SE-NE flanks and a single cinder cone on the
western flank. Slamet is composed of two overlapping edifices, an
older basaltic-andesite to andesitic volcano on the west and a younger
basaltic to basaltic-andesite one on the east. Gunung Malang II cinder
cone on the upper eastern flank on the younger edifice fed a lava flow
that extends 6 km to the east. Four craters occur at the summit of
Gunung Slamet, with activity migrating to the SW over time. Historical
eruptions, recorded since the 18th century, have originated from a 150-
m-deep, 450-m-wide, steep-walled crater at the western part of the
summit and have consisted of explosive eruptions generally lasting a
few days to a few weeks.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Slamet Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
during 3-8 June ash plumes from Batu Tara rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 40-75 km NW, W, and SW. On 9 June, an
ash plume drifted 140 km W.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, SERNAGEOMIN reported that during 27 May-8
June gas-and-ash plumes rose 1.5 km from Chaitén's growing Domo Nuevo
1 and Domo Nuevo 2 lava-dome complex. Collapses originating from
unstable slopes generated block-and-ash flows that were sometimes seen
from Chaitén town, 10 km SW. Ashfall was occasionally reported in
Chaitén town and nearby areas. The Alert Level remained at Red. Based
on analysis of satellite imagery, a SIGMET notice, and web camera
views, the Buenos Aires VAAC reported that during 5-9 June ash plumes
rose to altitudes of 1.5-3.7 km (5,000-12,000 ft) a.s.l. and drifted
WSW, SE, ENE, and NE. A thermal anomaly was also seen in satellite
imagery on 7 June.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
during 6-8 June ash plumes from Dukono drifted 20-75 km NW and NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 5, 8, and 9 June, INSIVUMEH reported that explosions from Fuego
produced ash plumes that rose to altitudes of 4.1-4.7 km
(13,500-15,400 ft) a.s.l. and drifted 10 km W, SW, and S. Some
explosions were accompanied by rumbling noises and shock waves
detected 12-15 km away. Avalanches descended several ravines.
Fumarolic plumes rose 150 m and drifted S and SW.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

Based on information from KEMSD, the Tokyo VAAC reported that on 6
June an eruption from Karymsky produced a plume that rose to an
altitude of 3.4 km (11,000 ft) a.s.l. Ash was not identified on
satellite imagery.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KELUT Eastern Java (Indonesia) 7.93°S, 112.308°E; summit elev. 1731 m

On 9 June, CVGHM reported that the Alert Level for Kelut was lowered
to 1 (on a scale of 1-4). No changes had been seen; occasional diffuse
white plumes rose 50-150 above the crater. CVGHM recommended that
people not approach the lava dome due to instability of the area and
the presence of potentially high temperatures and poisonous gases.

Geologic Summary. The relatively inconcspicuous 1,731-m-high Kelut
stratovolcano contains a summit crater lake that has been the source
of some of Indonesia's most deadly eruptions. A cluster of summit lava
domes cut by numerous craters has given the summit a very irregular
profile. More than 30 eruptions have been recorded from Gunung Kelut
since 1000 AD. The ejection of water from the crater lake during
Kelut's typically short, but violent eruptions has created pyroclastic
flows and lahars that have caused widespread fatalities and
destruction. After more than 5,000 people were killed during the 1919
eruption, an ambitious engineering project sought to drain the crater
lake. This initial effort lowered the lake by more than 50 m, but the
1951 eruption deepened the crater by 70 m, leaving 50 million cubic
meters of water after repair of the damaged drainage tunnels. After
more than 200 people were killed in the 1966 eruption, a new deeper
tunnel was constructed, lowering the lake's volume to only about 1
million cubic meters prior to the 1990 eruption.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Kelut Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 3-9 June, HVO reported that lava flowed SE from underneath
Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry. The
Kupapa'u ocean entry was again active starting on 4 or 5 June. Thermal
anomalies detected in satellite images and visual observations
revealed active surface flows above and in the abandoned Royal Gardens
subdivision, and on the TEB flow field.

The vent in Halema'uma'u crater continued to produce a predominantly
white plume that drifted mainly SW. Small amounts of tephra, including
Pele's hair and fresh spatter, were retrieved from collection bins
placed near the plume during the reporting period. A molten lava pool
near the base of the cavity, about 100 m below the floor of the
crater, produced bright incandescence. Lava was clearly visible in the
Halema'uma'u Overlook Vent webcam on 5 June. On 8 and 9 June, sounds
resembling rushing gas and rockfalls were heard in the vicinity of the
crater. The sulfur dioxide emission rate at the summit remained
elevated; measurements were 700 and 800 tonnes per day on 4 and 5
June, respectively. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

SERNAGEOMIN reported that during 5-8 June incandescence from an area
in the SW part of Llaima's main crater corresponded to a small active
"outcrop of lava." On 6 June, incandescence emanated from a small
point along the E-flank fissure. Gas and steam was emitted from an
area W of the main crater. The Volcano Alert Level remained at Yellow.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 8 June an ash plume from Manam rose to an altitude of 2.4 km (8,000
ft) a.s.l. and drifted about 40 km NW.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Manam Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 5, 8, and 9 June, INSIVUMEH reported that fumarolic plumes from
Pacaya's MacKenney cone rose 50-200 m and drifted W and SW. During the
reporting period, two to four lava flows, each 150-300 m long, were
emitted from an area on the lower S flank, SW from the main edifice.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that emissions of steam and gas from Popocatépetl
were visible during 3-9 June; the plumes contained slight amounts of
ash during 8-9 June.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 29 May-6 June white and occasionally blue
plumes from Rabaul caldera's Tavurvur cone rose 1 km above the crater.
Incandescence from the summit crater was seen at night. On 5 June, an
ash plume drifted NW and caused ashfall in Rabaul town (3-5 km NW) and
surrounding areas.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Herman Patia, Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

AVO reported that during 3-9 June seismicity from Redoubt remained
low, but above background levels; small discrete earthquakes and
rockfall signals in the summit region were recorded. Growth of the
lava dome in the summit crater continued and by 5 June extended 950 m
down the N flank. Cloudy conditions often obscured satellite and web
camera views; steaming from the summit region was seen periodically.
On 3 June, a minor dusting of ash was visible on the NE flank, likely
related to rockfall activity. AVO warned that the unstable lava dome
could fail with little or no warning, leading to significant ash
emissions and possible lahars in the Drift River valley. The Volcanic
Alert Level remained at Watch and the Aviation Color Code remained at
Orange.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that on 7 June
an eruption from Sakura-jima produced a plume that rose vertically to
an altitude of 3 km (10,000 ft) a.s.l. An eruption on 9 June resulted
in a plume that rose to an attitude of 2.4 km (8,000 ft) a.s.l. and
drifted N.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 5, 8, and 9 June explosions from Santa
María's Santiaguito lava dome complex produced ash plumes that rose to
altitudes of 2.8-3.3 km (9,200-10,800 ft) a.s.l. and drifted SW. Gas
plumes that were sometimes gray rose 300-600 m above Caliente dome.
Avalanches descended the S and W flanks.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 29 May-5 June seismic activity from
Shiveluch was above background levels. Based on interpretations of
seismic data, diffuse ash plumes were emitted during the reporting
period; an ash plume possibly rose to an altitude of 3.8 km (12,500
ft) a.s.l. on 1 June. Video camera images showed steam-and-gas
emissions. Analysis of satellite imagery revealed a daily thermal
anomaly over the lava dome. The Level of Concern Color Code remained
at Orange. Based on analysis of satellite imagery, the Tokyo VAAC
reported on 7 June that a possible eruption produced a plume that rose
to an altitude of 3.4 km (11,000 ft) a.s.l. and drifted SW. A report a
few hours later stated that ash emissions were continuing.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 3-9 June tremor and explosions from
Tungurahua were detected by the seismic network. On 3 June, lahars
traveled down multiple drainages. A gas-and-ash plume rose 200 m and
drifted SW; cloudy conditions prevented visual observations during the
rest of the reporting period. Ashfall was detected in areas to the SW
and W on 4 June. On 7 June, noises resembling blocks rolling down the
flanks, "cannon shots," and roars were reported. The next day, "cannon
shot" noises were followed by the vibration of windows in nearby
areas.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

Based on analysis of satellite imagery, the Buenos Aires VAAC reported
that on 5 June plumes from Ubinas rose to altitudes of 6.1-6.7 km
(20,000-22,000 ft) a.s.l. and drifted W and S. A pilot reported that
an ash plume rose to an altitude of 7.9 km (26,000 ft) a.s.l. and
drifted SW. On 6 and 9 June, plumes seen on satellite imagery rose to
altitudes of 6.1-7.6 km (20,000-25,000 ft) a.s.l. and drifted S and
NE, respectively.

Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of
Ubinas, Peru's most active volcano, gives it a truncated appearance.
Ubinas is the northernmost of three young volcanoes located along a
regional structural lineament about 50 km behind the main volcanic
front of Peru. The upper slopes of the stratovolcano, composed
primarily of Pleistocene andesitic lava flows, steepen to nearly 45
degrees. The steep-walled, 150-m-deep summit caldera contains an ash
cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-
avalanche deposits from the collapse of the SE flank of Ubinas extend
10 km from the volcano. Widespread Plinian pumice-fall deposits from
Ubinas include some of Holocene age. Holocene lava flows are visible
on the volcano's flanks, but historical activity, documented since the
16th century, has consisted of intermittent minor explosive eruptions.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Ubinas Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

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Jun 10, 2009, 8:33:41 PM6/10/09

to

Header corrected

3 June-9 June 2009

New Activity/Unrest:

Ongoing Activity:

New Activity/Unrest

Map

> > CVGHM reported that during 1-6 June lava flows from Karangetang
> traveled 50 m E and 600 m SE. Incandescent rocks, from the main> craters and ends of the lava flows, traveled as far as 2 km towards> multiple river valleys, including the Keting River to the S. On 1> June, white-to-gray-to-brownish plumes rose 700 m above the main> crater. Incandescent lava was ejected 500-700 m. On 4 June, tremor> amplitude and the number of earthquakes decreased. During 4-6 June,> white plumes rose 50-300 m from the main crater. On 7 and 8 June, fog> often prevented observations and incandescent rocks were rarely seen.> The Alert Level was lowered to 3 (on a scale of 1-4) on 9 June.>
> Geologic Summary. Karangetang (also known as Api Siau) lies at the> northern end of the island of Siau, N of Sulawesi, and contains five> summit craters strung along a N-S line. One of Indonesia's most active> volcanoes, Karangetang has had more than 40 recorded eruptions since> 1675. Twentieth-century eruptions have included frequent explosions,> sometimes accompanied by pyroclastic flows and lahars.>
> Map>

> Source: Center of Volcanology and Geological Hazard Mitigation CVGHM)

Karangetang [Api Siau] Information from the Global Volcanism Program

SANGEANG API Lesser Sunda Islands (Indonesia) 8.20°S, 119.07°E; ummit
elev. 1949 m

CVGHM reported that on 4 June the Alert Level for Sangeang Api was
raised to 2 (on a scale of 1-4) due to recent increases in the number
of earthquakes. White plumes rose 5-25 m during 1 May-3 June.

Geologic Summary. Sangeang Api volcano, one of the most active in the
Lesser Sunda Islands, forms a small 13-km-wide island off the NE
coast
of Sumbawa Island. Two large trachybasaltic-to-tranchyandesitic
volcanic cones, 1949-m-high Doro Api and 1795-m-high Doro Mantoi,
were
constructed in the center and on the eastern rim, respectively, of an
older, largely obscured caldera. Flank vents occur on the south side
of Doro Mantoi and near the northern coast. Intermittent historical
eruptions have been recorded since 1512.

Map

Source: Center of Volcanology and Geological Hazard Mitigation CVGHM)

Sangeang Api Information from the Global Volcanism Program SLAMET
Central Java (Indonesia) 7.242°S, 109.208°E; summit elev. 3428 m

CVGHM reported that during 26 May-4 June activity from Slat

Map

Source: Center of Volcanology and Geological Hazard Mitigation CVGHM)

Slamet Information from the Global Volcanism Program
Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
during 3-8 June ash plumes from Batu Tara rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 40-75 km NW, W, and SW. On 9 June,
an
ash plume drifted 140 km W.

Geologic Summary. The small isolated island of Batu Tara in the
Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to
within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, SERNAGEOMIN reported that during 27 ay-8
June gas-and-ash plumes rose 1.5 km from Chaitén's growing Domo uevo

1 and Domo Nuevo 2 lava-dome complex. Collapses originating from>
unstable slopes generated block-and-ash flows that were sometimes see

from Chaitén town, 10 km SW. Ashfall was occasionally reported in
Chaitén town and nearby areas. The Alert Level remained at Red. Based
on analysis of satellite imagery, a SIGMET notice, and web camera
views, the Buenos Aires VAAC reported that during 5-9 June ash plumes
rose to altitudes of 1.5-3.7 km (5,000-12,000 ft) a.s.l. and drifted
WSW, SE, ENE, and NE. A thermal anomaly was also seen in satellite
imagery on 7 June.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the
Gulf

of Corcovado. A pyroclastic-surge and pumice ...

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Jun 17, 2009, 2:56:26 PM6/17/09

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SI / USGS Weekly Volcanic Activity Report

10 June-16 June 2009

New Activity/Unrest:

| Rinjani, Lombok Island (Indonesia)
| Sangay, Ecuador
| Sarychev Peak, Matua Island

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Ebeko, Paramushir Island
| Galeras, Colombia
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Popocatépetl, México
| Rabaul, New Britain
| Redoubt, Southwestern Alaska
| Sakura-jima, Kyushu

This page is updated on Wednesdays,
please see the GVP Home Page for news
of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

RINJANI Lombok Island (Indonesia) 8.42°S, 116.47°E; summit elev. 3726
m

Base on analysis of satellite imagery, the Darwin VAAC reported that
during 11-12 and 16 June ash plumes from Rinjani rose to an altitude
of 4 km (13,000 ft) a.s.l. and drifted 15-55 km W and WSW.

Geologic Summary. Rinjani volcano on the island of Lombok rises to
3,726 m, second in height among Indonesian volcanoes only to Sumatra's
Kerinci volcano. Rinjani has a steep-sided conical profile when viewed
from the E, but the W side of the compound volcano is truncated by the
6 x 8.5 km, oval-shaped Segara Anak caldera. The western half of the
caldera contains a 230-m-deep lake whose crescentic form results from
growth of the post-caldera cone Barujari at the E end of the caldera.
Historical eruptions at Rinjani dating back to 1847 have been
restricted to Barujari cone and consist of moderate explosive activity
and occasional lava flows that have entered Segara Anak lake.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Rinjani Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on analysis of satellite imagery, the Washington VAAC reported
that on 15 June possible small ash plumes from Sangay drifted WNW. A
thermal anomaly was detected.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

Based on analysis of satellite imagery, SVERT reported that on 11 June
a thermal anomaly from Sarychev Peak and a possible diffuse ash plume
were detected. Seismicity was at background levels. The next day, a
large thermal anomaly was present and ash emissions were were seen on
satellite imagery. On 13 June, ash plumes rose to an altitude of 7.5
km (24,600 ft) a.s.l. and drifted 200 km SW and 105 km SE. On 14 June,
a large eruption produced an ash plume that rose to an altitude of 12
km (39,400 ft) a.s.l. A large explosion the next day sent an ash plume
to an altitude of 8 km (26,200 ft) a.s.l. Sarychev Peak is not
monitored with ground-based instruments. According to news articles,
some airlines have re-routed, canceled, or delayed flights.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Sources: Sakhalin Volcanic Eruption Response Team (SVERT), The
Province, Canada.com

Sarychev Peak Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analysis of satellite imagery, the Darwin VAAC reported that

during 10-16 June ash plumes from Batu Tara rose to altitudes of
1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted 25-185 km SW, NW, N,
and NE.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, analysis of satellite imagery, and a SIGMET
notice, the Buenos Aires VAAC reported that on 11 and 14 June ash
plumes from Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex
rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted NE
and SE. A thermal anomaly was also seen in satellite imagery on 11
June.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf

of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analysis of satellite imagery, the Darwin VAAC reported that

on 16 June an ash plume from Dukono rose to an altitude of 1.5 km
(5,000 ft) a.s.l. and drifted 40 km NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

KVERT reported that during 9-10 June gas-and-steam plumes from Ebeko
rose to an altitude of 2.7 km (8,900 ft) a.s.l. The Level of Concern
Color Code remained at Yellow. Based on analysis of satellite imagery
and information from Yelizovo Airport, the Tokyo VAAC reported that on
13 June an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l.
and drifted SW.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Ebeko Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

On 10 June, INGEOMINAS reported that the Alert Level for Galeras was
lowered to II (Orange; "probable eruption in term of days or weeks").
Pulsating steam plumes rose from the crater and drifted NW. Seismicity
remained low.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 10-16 June, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex

through a lava tube system, reaching the Waikupanaha and Kupapa'u
ocean entries. Thermal anomalies detected in satellite images and
visual observations revealed active surface flows on the pali and on
the TEB flow field. Explosions from the Waikupanaha ocean entry were
reported on 13 June.

The vent in Halema'uma'u crater continued to produce a predominantly
white plume that drifted mainly SW. Small amounts of tephra, including
Pele's hair and fresh spatter, were retrieved from collection bins
placed near the plume during the reporting period. A molten lava pool
near the base of the cavity, about 100 m below the floor of the

crater, produced bright incandescence. The Halema'uma'u Overlook Vent
webcam that has a view into the vent cavity showed a draining event
from the actively bubbling lava pond on the evening of 12 June. Sounds
resembling rushing gas and rockfalls were occasionally heard in the

vicinity of the crater. The sulfur dioxide emission rate at the summit

remained elevated; measurements were 1,100 and 1,000 tonnes per day on
11 and 12 June, respectively. The 2003-2007 average rate was 140
tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

On 11 June, KVERT reported that seismic activity from Kliuchevskoi had
remained at background levels since 12 May. Weak intermittent volcanic
tremor and fumarolic activity continued to be detected. The Level of
Concern Color was lowered to Green.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 10-16 June emissions of steam and gas
from Popocatépetl sometimes contained slight amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 7-11 June white and occasionally blue plumes
from Rabaul caldera's Tavurvur cone rose 1.5 km above the crater.
Incandescence from the summit crater was seen at night. Based on

analysis of satellite imagery, the Darwin VAAC reported that during

11-12 and 16 June ash plumes rose to altitudes of 1.5-2.1 km
(5,000-7,000 ft) a.s.l. and drifted 25-45 km SE, E, and NE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Ima Itikarai, Rabaul Volcano Observatory (RVO), Darwin

Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

AVO reported that during 10-15 June seismicity from Redoubt remained
low, but above background levels; small discrete earthquakes in the
summit region associated with dome growth and instability were
recorded. Clear web camera views on 10, 11, and 16 June showed
steaming from the summit region. On 12 June, the lava dome was an
estimated 1 km long, 460 m wide, and 200 m high. The Volcanic Alert

Level remained at Watch and the Aviation Color Code remained at
Orange.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on a pilot observation, the Tokyo VAAC reported that on 12 June
an ash plume from Sakura-jima rose to an altitude of 1.8 km (6,000 ft)
a.s.l. The JMA reported that during 14-16 June eruptions produced
plumes that rose to altitudes of 2.4-2.7 km (8,000-9,000 ft) a.s.l.
Plumes drifted SE and E on 14 and 15 June.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 5-11 June seismic activity from Shiveluch

was above background levels. Based on interpretations of seismic data,

diffuse ash plumes were emitted during the reporting period; ash
plumes possibly rose to altitudes of 4.8-7.7 km (16,000-25,300 ft)
a.s.l. during 6 and 10-11 June. Video camera images showed steam-and-
gas emissions. Analysis of satellite imagery revealed a daily thermal
anomaly over the lava dome, and ash plumes that drifted 90 km S on 6
and 7 June. The Level of Concern Color Code remained at Orange. Based
on analysis of satellite imagery and information from KEMSD, the Tokyo
VAAC reported that during 11-12 and 14-15 June eruptions produced
plumes that rose to altitudes of 6.1-7.9 km (20,000-26,000 ft) a.s.l.
A possible eruption was seen on satellite imagery on 13 June.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion
from Suwanose-jima on 16 June. Details of a possible resultant ash
plume were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 10-15 June tremor and explosions from
Tungurahua were detected by the seismic network. Ash plumes rose to a
maximum altitude of 7 km (23,000 ft) a.s.l. during 10-11 and 14 June;
cloud cover frequently prevented observations during the reporting
period. Ashfall was reported almost daily, mostly to the W. Some
explosions were accompanied by "cannon shot" sounds or sounds
resembling blocks rolling down the flanks. Windows occasionally
vibrated.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

On 14 June, OVSICORI-UNA reported that fumarolic activity from
Turrialba had been observed all around the upper flanks of the active
W crater. During the previous two months, the fumarolic activity was
accompanied by widening of radial cracks (1.5 cm on average), 1-2 km
tall gas-and-vapor plumes, and one sustained discrete seismic swarm.
Temperatures of fumarolic vents in the lower parts of the crater were
between 120 and 160 degrees Celsius. The temperature of summit cracks
was 94 degrees Celsius. Dairy pastures and forests had been burned as
far away as 3.5 km NW and W.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Observatorio Vulcanológico y Sismológico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Turrialba Information from the Global Volcanism Program

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

Based on SIGMET notices and analysis of satellite imagery, the Buenos
Aires VAAC reported that during 11 and 13-15 June eruptions from
Ubinas produced ash plumes that rose to altitudes of 5.5-7.9 km
(18,000-26,000 ft) a.s.l. Plumes drifted NE, E, and SE. Ash was not
identified on satellite imagery on 13 June.

Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of
Ubinas, Peru's most active volcano, gives it a truncated appearance.
Ubinas is the northernmost of three young volcanoes located along a
regional structural lineament about 50 km behind the main volcanic
front of Peru. The upper slopes of the stratovolcano, composed
primarily of Pleistocene andesitic lava flows, steepen to nearly 45
degrees. The steep-walled, 150-m-deep summit caldera contains an ash
cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-
avalanche deposits from the collapse of the SE flank of Ubinas extend
10 km from the volcano. Widespread Plinian pumice-fall deposits from
Ubinas include some of Holocene age. Holocene lava flows are visible
on the volcano's flanks, but historical activity, documented since the
16th century, has consisted of intermittent minor explosive eruptions.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

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Jun 24, 2009, 6:19:26 PM6/24/09

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USGS Weekly Volcanic Activity Report

17 June-23 June 2009

New Activity/Unrest:

| Rinjani, Lombok Island (Indonesia)
| Sarychev Peak, Matua Island

Ongoing Activity:

| Arenal, Costa Rica
| Bezymianny, Central Kamchatka (Russia)
| Chaitén, Southern Chile

| Ebeko, Paramushir Island
| Galeras, Colombia

| Rabaul, New Britain
| Redoubt, Southwestern Alaska

| Shiveluch, Central Kamchatka (Russia)
| Tungurahua, Ecuador

This page is updated on Wednesdays, please see the GVP Home Page for

news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

RINJANI Lombok Island (Indonesia) 8.42°S, 116.47°E; summit elev. 3726
m

Based on analysis of satellite imagery, the Darwin VAAC reported that
during 21 June ash plumes from Rinjani rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 55 km N.

Geologic Summary. Rinjani volcano on the island of Lombok rises to
3,726 m, second in height among Indonesian volcanoes only to Sumatra's
Kerinci volcano. Rinjani has a steep-sided conical profile when viewed
from the E, but the W side of the compound volcano is truncated by the
6 x 8.5 km, oval-shaped Segara Anak caldera. The western half of the
caldera contains a 230-m-deep lake whose crescentic form results from
growth of the post-caldera cone Barujari at the E end of the caldera.
Historical eruptions at Rinjani dating back to 1847 have been
restricted to Barujari cone and consist of moderate explosive activity
and occasional lava flows that have entered Segara Anak lake.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Rinjani Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

The eruption from Sarychev Peak that began on 11 June continued
through the 19th. SVERT reported another explosive eruption at 1730
UTC on 15 June, followed by the satellite observation of a plume early
on 16 June that extended 360 km NW. The Tokyo VAAC estimated that the
16 June plume rose to an altitude of 9.7 km (32,000 feet) a.s.l.,
while higher ash clouds from earlier explosions reached 13.7 km
(45,000 feet) altitude. Ash emissions continued during 17-18 June,
causing ashfall in Yuzhno-Sakhalinsk, and gas-and-steam plumes spread
NE and SW. Thermal anomalies were detected in satellite data on 18 and
19 June, but cloudy conditions prevented clear observations. One MODIS
image on 18 June showed an ash plume spreading SW above the weather
clouds. Although the Aviation Color Code was lowered from Red to
Orange on 19 June, satellite observations showed that a diffuse ash
cloud had spread approximately 20 km S and 40 km W of the volcano.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

Three strong eruptions on 16 June resulted in pyroclastic flows. The
National Park was evacuated as a precaution, but reopened the next
day. Increased degassing the previous week had prompted an elevation
of the hazard status to Level 3 (on a scale of 1-4).

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Sources: Inside Costa Rica, Tico Times

Arenal Information from the Global Volcanism Program

BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit
elev. 2882 m

Reports from KVERT since August 2008 have indicated continuing dome
growth and weak fumarolic activity at Bezymianny, with thermal
anomalies visible in satellite data when the volcano was visible. Over
the previous month such anomalies were seen on 21 and 30 May, and 2-4,
7, and 11-14 June.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny
volcano had been considered extinct. Three periods of intensified
activity have occurred during the past 3,000 years. The latest period,
which was preceded by a 1,000-year quiescence, began with the dramatic
1955-56 eruption. That eruption, similar to the 1980 event at Mount
St. Helens, produced a large horseshoe-shaped crater that was formed
by collapse of the summit and an associated lateral blast. Subsequent
episodic but ongoing lava-dome growth, accompanied by intermittent
explosive activity and pyroclastic flows, has largely filled the 1956
crater.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bezymianny Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

As noted in an OVDAS-SERNAGEOMIN report, eruptive activity continued
during 8-16 June with sustained growth of the lava dome complex, from
which block-and-ash flows were generated. Steam-and-ash plumes
generally rose 1.5 km above the dome. Seismicity remained at typical
levels. The Alert Level remained at Red.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Chaitén Information from the Global Volcanism Program

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

KVERT reported that gas-and-steam plumes rose to an altitude of 1.7 km
(5,600 ft) a.s.l. during 13-18 June. The Level of Concern Color Code
remained at Yellow.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Ebeko Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

Increased sulfur-dioxide degassing and seismicity related to fluid
movement, resulting in the overall lowering of pressure in the system,
prompted INGEOMINAS to further lower the alert level to Yellow (Level
III) on 19 June. By 23 June some rock-fracture seismicity had been
detected, though events related to fluid movement had declined
significantly. That same day clear weather allowed observation of a
small gas column with minor ash content, while scientists on a
monitoring flight saw gas emissions near the crater rim and recorded a
thermal anomaly within the main crater.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

Satellite data reported by KVERT indicated a weak thermal anomaly over
the volcano on 4-6 and 13-14 June. Gas-and-steam plumes extended 30 km
SE on 4 June. The Level of Concern Color Code remained at Yellow.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

Daily reports from HVO about Kilauea during 17-23 June indicated
continuing visible glow from the Halema'uma'u vent. Molten lava
remained in the neck of a funnel-shaped cavity in the floor of
Halema'uma'u Crater. Webcam views showed the lava level rising several
meters for brief periods before returning to depths of about 290 m
below the crater rim and 205 m below the crater floor, as determined
by laser-ranging measurements. Throughout the week lava from east rift
zone vents flowed through tubes to the coast and entered the ocean at
two locations west of Kalapana; active surface flows also continued on
the pali within the abandoned Royal Gardens subdivision. Sulfur
dioxide emission rates from the Halema`uma`u and Pu`u `O`o vents
remained elevated. The plume continued to carry glassy bits of spatter
and small amounts of ash. A deflation-inflation event began on 22 June
and was continuing the next day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KORYAKSKY Eastern Kamchatka 53.320°N, 158.688°E; summit elev. 3456 m

Moderate to strong fumarolic activity at Koryaksky has been reported
by KVERT in recent weeks. Satellite data showed a weak thermal anomaly
over the volcano 11 and 13 June. The Level of Concern Color Code
remained at Yellow.

Geologic Summary. The large symmetrical Koryaksky stratovolcano is the
most prominent landmark of the NW-trending Avachinskaya volcano group,
which towers above Kamchatka's largest city, Petropavlovsk. Erosion
has produced a ribbed surface on the eastern flanks of the 3456-m-high
volcano; the youngest lava flows are found on the upper western flank
and below SE-flank cinder cones. No strong explosive eruptions have
been documented during the Holocene. Extensive Holocene lava fields on
the western flank were primarily fed by summit vents; those on the SW
flank originated from flank vents. Lahars associated with a period of
lava effusion from south- and SW-flank fissure vents about 3900-3500
years ago reached Avacha Bay. Only a few moderate explosive eruptions
have occurred during historical time. Koryaksky's first historical
eruption, in 1895, also produced a lava flow.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Koryaksky Information from the Global Volcanism Program

KRAKATAU Indonesia 6.102°S, 105.423°E; summit elev. 813 m

A news report on 18 June noted that activity at Krakatau had increased
significantly. According to the head of the volcano monitoring post in
Pasauran village there were 828 small eruptions in the previous six
days, reaching the rate of a new explosion every three minutes.
Observers on beaches in Java could clearly see rising white gas-and-
steam plumes along with incandescent ejecta at night. Residents also
reported loud explosion noises. The level of activity decreased again
on 19 June, and the Alert Level remained at 3 (on a scale of 1-4).

Geologic Summary. Renowned Krakatau volcano lies in the Sunda Strait
between Java and Sumatra. Collapse of the ancestral Krakatau edifice,
perhaps in 416 AD, resulted in a 7-km-wide caldera. Remnants of this
volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan
and Perbuwatan volcanoes were formed, coalescing to create the
pre-1883 Krakatau Island. Caldera collapse during the catastrophic
1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only
a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau
(Child of Krakatau), constructed within the 1883 caldera at a point
between the former cones of Danan and Perbuwatan, has been the site of
frequent eruptions since 1927.

Map

Source: Antara News

Krakatau Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

The camera in Melipueco used by OVDAS-SERNAGEOMIN to monitor Llaima
again showed glow on the NW inner margin of the main crater during
9-16 June. Occasional steam emissions with minor amounts of ash were
also seen from the E flank. Seismic tremor has also increased since 5
June. The Alert Level remained at Yellow.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

An RVO report for 12-18 June noted that the Tavurvur cone at Rabaul
produced pale gray ash plumes during 16-17 June. Activity after that
consisted primarily of dense white steam plumes, with occasional ash
emissions. Continuous glow was seen at night.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Ima Itikarai, Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

Seismicity at Redoubt, as reported by AVO, was low during 17-23 June,
but remained above background level. Seismicity was primarily
comprised of small, discrete events associated with continued growth
and instability of the lava dome. Webcam images on 19 and 23 June
showed continued steam and gas emissions from the dome. Poor weather
conditions throughout the week limited fieldwork opportunities, but
one crew was able to observe the dome on 15 June. The Volcanic Alert

Level remained at Watch and the Aviation Color Code remained at
Orange.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

A new viscous lava flow from the lava dome was reported by KVERT
during 11-18 June. Satellite thermal data indicated a large anomaly
over the lava dome the entire week. Above-background levels of
seismicity persisted throughout that time. Video recordings revealed
ash plumes up to an altitude of 6.1 km (20,000 ft) a.s.l on 12-15 and
18 June. Ash plumes extended up to 50 km (31 miles) to the south 11
and 13-14 June. Another ash cloud on 12 June was 40 x 20 km in size at
a distance of 140 km (87 miles) SW. Moderate to strong gas-and-steam
plumes were observed during other times.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Continued moderate seismic and eruptive activity was reported by the
IG during 17-23 June. Explosions with resulting ashfall were reported
on most days. Lava fountains were observed on the night of 21 June
rising to a height of 500 m above the crater. Incandescent blocks seen
over the next two days rolled as far as 2 km downslope.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

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Jul 1, 2009, 10:20:45 PM7/1/09

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SI / USGS Weekly Volcanic Activity Report

New Activity/Unrest:

| Cleveland, Chuginadak Island
| Sarychev Peak, Matua Island

Ongoing Activity:

| Arenal, Costa Rica

| Bagana, Bougainville
| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Galeras, Colombia
| Kilauea, Hawaii (USA)

| Rabaul, New Britain
| Redoubt, Southwestern Alaska
| Sakura-jima, Kyushu

| Sangay, Ecuador

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Slamet, Central Java (Indonesia)

| Soufrière Hills, Montserrat
| Tungurahua, Ecuador

This page is updated on Wednesdays, please see

the GVP Home Page for news of the latest
significant activity.

The Weekly Volcanic Activity Report is a cooperative project between

the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

A small explosive eruption of Cleveland on 25 June prompted AVO to
raise the Volcano Alert Level to Watch and the Aviation Color Code to
Orange. An ash cloud that detached from the volcano was seen on
satellite imagery moving S at an estimated altitude of 4.6 km (15,000
ft) a.s.l. No further activity was reported. On 27 June, AVO lowered
the Volcano Alert Level to Advisory and the Aviation Color Code to
Yellow.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that an intense thermal anomaly from Sarychev Peak was
detected on satellite imagery during 24-30 June. Gas-and-steam plumes
drifted 9 km NW on 24 June, S on 26 June, 26 km SSE on 28 June, and 40
km SE at an altitude of 3 km on 29 June.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during May activity originating from
Arenal's Crater C consisted of gas emissions, sporadic Strombolian
eruptions, and occasional avalanches that traveled down the SW, S, and
N flanks. Acid rain and small amounts of ejected pyroclastic material
affected the NE and SE flanks. Small avalanches traveled down several
ravines. Crater D produced only fumarolic activity.

A small eruption on 16 June was verified by field observations on 17
June. The eruption caused avalanches that descended the S flank to an
800-m elevation a.s.l. An ash plume drifted W.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 27 June an ash plume from Bagana rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 110 km SW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.

748 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
during 25-30 June ash plumes from Batu Tara rose to an altitude of 1.5
km (5,000 ft) a.s.l. and drifted 35-130 km SW, W, and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views from the S, SERNAGEOMIN reported that during
16-23 June gas-and-ash plumes rose 1.5 km from Chaitén's growing Domo
Nuevo 1 and Domo Nuevo 2 lava-dome complex. Collapses originating from
unstable slopes generated block-and-ash flows. The Alert Level
remained at Red. Based on SIGMET notices and web camera views, the
Buenos Aires VAAC reported that during 24-25 and 27-28 June ash plumes
rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted W,
S, E, and NE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 28 June an ash plume from Dukono rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 75 km N.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

INGEOMINAS reported that during 22-23 June gas plumes rising from
Galeras contained some ash. An overflight on 23 June revealed that
temperatures in the main crater measured between 60 and 120 degrees
Celsius, except for a small zone where the temperature measured 220
degrees Celsius. Gas emissions originated from the periphery of the
main crater. On 26 June, seismicity similar to that seen prior to
previous eruptions, along with low rates of gas emissions, prompted
INGEOMINAS to raise the Alert Level to II (Orange; "probable eruption

in term of days or weeks").

Geologic Summary. Galeras, a stratovolcano with a large breached

caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 24-30 June, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha and Kupapa'u
ocean entries. Thermal anomalies detected in satellite images and
visual observations revealed active surface flows on the pali and on

the TEB flow field. Explosions from both ocean entries were
occasionally reported. On 28 June, officials reported a wide swath of
lava flows descending the pali.

The vent in Halema'uma'u crater continued to produce a predominantly

white plume that drifted mainly SW. Small amounts of ash-sized tephra,

including Pele's hair and fresh spatter, were retrieved from
collection bins placed near the plume during the reporting period. A

molten lava pool (54 m in diameter) near the base of the cavity, about
290 m below the floor of the crater, produced incandescence of
variable brightness. The level of the lava pond rose periodically.

Sounds resembling rushing gas and rockfalls were occasionally heard in
the vicinity of the crater. The sulfur dioxide emission rate at the

summit remained elevated; measurements were 800 tonnes per day on 24
and 26 June. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 19-25 June gray ash plumes from Rabaul
caldera's Tavurvur cone rose 1.5 km above the crater and produced

ashfall in Rabaul town (3-5 km NW) and surrounding areas.

Incandescence from the summit crater was seen at night. Based on
analysis of satellite imagery, the Darwin VAAC reported that during
26-28 June ash plumes rose to an altitude of 1.5 km (5,000 ft) a.s.l.
and drifted 35-75 km NW and W.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

AVO reported that during 24-29 June seismicity from Redoubt was low,
but remained above background levels. Web camera images showed
continued steaming from the lava dome at the summit. No ash signals
were observed in radar or satellite imagery. Occasional observations,
the low level of seismicity, and low gas emissions suggested that the
growth of the lava dome had significantly slowed. On 30 June, AVO
lowered the Volcanic Alert Level to Advisory and the Aviation Color
Code to Yellow.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during
24-30 June explosions from Sakura-jima sometimes produced plumes that
rose to altitudes of 2.1-3.4 km (7,000-11,000 ft) a.s.l. The plumes
drifted NE, E, and S.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on a pilot observation, the Washington VAAC reported that on 26
June an ash plume from Sangay rose to an altitude of 7.6 km (25,000
ft) a.s.l. The suspected ash was seen on satellite imagery drifting
less than 30 km W.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 26 and 29 June explosions from Santa
María's Santiaguito lava dome complex produced ash plumes that rose to
altitudes of 2.9-3.3 km (9,500-10,800 ft) a.s.l. and drifted W and SW.
Fumarolic plumes rose 100-200 m above Caliente dome. On 26 June, the
seismic network detected a lahar that travelled S down the Nima I
river. Steam plumes and a sulfur odor rose from the deposits. The
lahar was 15 m wide and 1 m thick at the toe, and carried blocks up to
1.5 m in diameter.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 19-26 June seismic activity from Shiveluch

was above background levels. Based on interpretations of seismic data,

steam-and-gas plumes with some ash content were emitted during the
reporting period; ash plumes possibly rose to an altitude of 6.8 km
(20,000 ft) a.s.l. On 20 June, ash plumes seen on a video camera rose
to an altitude of 5 km (16,400 ft) a.s.l. Gas-and-steam activity was
observed at other times during the reporting period. Analysis of
satellite imagery revealed a daily thermal anomaly over the lava dome.
Ash plumes were also seen on satellite imagery drifting 114 km S
during 20 and 22-24 June and more than 100 km SW and NE on 25 June. A
pyroclastic flow occurred on 25 June. The Level of Concern Color Code
remained at Orange. Based on analysis of satellite imagery and
information from KEMSD, the Tokyo VAAC reported that during 27-28 and
30 June eruptions produced plumes that rose to altitudes of 4.9-7 km
(16,000-23,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SLAMET Central Java (Indonesia) 7.242°S, 109.208°E; summit elev. 3428
m

CVGHM reported that during 8-28 June tephra was ejected 50-700 m above
Slamet's crater and incandescent material was ejected 50-300 m above
the crater. Booming noises were reported. During 23-29 June,
incandescence and ash emissions were not observed. On 29 June, CVGHM
lowered the Alert Level for Slamet to 2 (on a scale of 1-4) because of
decreased seismicity and emissions.

Geologic Summary. Slamet, Java's second highest volcano at 3428 m and
one of its most active, has a cluster of about three dozen cinder
cones on its lower SE-NE flanks and a single cinder cone on the
western flank. Slamet is composed of two overlapping edifices, an
older basaltic-andesite to andesitic volcano on the west and a younger
basaltic to basaltic-andesite one on the east. Gunung Malang II cinder
cone on the upper eastern flank on the younger edifice fed a lava flow
that extends 6 km to the east. Four craters occur at the summit of
Gunung Slamet, with activity migrating to the SW over time. Historical
eruptions, recorded since the 18th century, have originated from a 150-
m-deep, 450-m-wide, steep-walled crater at the western part of the
summit and have consisted of explosive eruptions generally lasting a
few days to a few weeks.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Slamet Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 19-26 June activity from the Soufrière Hills
lava dome was at a low level. On 20 June, a small pyroclastic flow
that traveled E down the Tar River valley produced a small ash cloud
that drifted W. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that tremor and explosions from Tungurahua were
detected by the seismic network almost daily during 23-30 June. A
plume with low ash content rose to an altitude of 7 km (23,000 ft)
a.s.l. on 23 June and drifted W, and a small ash plume rose 200 m
above the crater on 29 June. Cloud cover frequently prevented
observations during the rest of the reporting period. Ashfall was
occasionally reported in areas to the W and SW. Sounds resembling
blocks rolling down the flanks and "cannon shot" noises were sometimes
reported. On 23 June, lava fountains at the summit were observed and
blocks ejected from the crater rolled as far as 1 km down the flanks.
On 27 June, the seismic network possibly detected lahars in area
drainages.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

Last Post

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Jul 8, 2009, 6:51:05 PM7/8/09

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SI / USGS Weekly Volcanic Activity Report

1 July-7 July 2009

New Activity/Unrest:

| Manda Hararo, Northeastern Africa
| Mayon, Luzon
| San Miguel, El Salvador
| Sarychev Peak, Matua Island

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile
| Dukono, Halmahera

| Kilauea, Hawaii (USA)
| Krakatau, Indonesia
| Rabaul, New Britain
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)
| Tungurahua, Ecuador | Ubinas, Perú

This page is updated on Wednesdays,
please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between

the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

MANDA HARARO Northeastern Africa 12.17°N, 40.82°E; summit elev. 600+ m

A large sulfur dioxide plume and several thermal anomalies from Manda
Hararo were detected in satellite imagery during 28-30 June. Thermal
anomalies detected in satellite imagery indicated a surface lava flow
in the Karbahi region. Karbahi is a graben area with numerous active
faults, fissures, and basalt flows, NW of the center of the broad
Manda Hararo volcanic complex. Preliminary data suggested that the
eruption was larger than the previous eruption in August 2007. On 8
July, a scientist that visited the area reported fresh lava flows, an
eruptive fissure that was about 5 km long, and gas emitting from
multiple cones.

Geologic Summary. The southernmost axial range of western Afar, the
Manda Hararo complex is located in the Kalo plain, SSE of Dabbahu
volcano. The massive complex is 105 km long and 20-30 km wide, and
represents an uplifted segment of a mid-ocean ridge spreading center.
A small basaltic shield volcano is located at the northern end of the
complex, south of which is an area of abundant fissure-fed lava flows.
Two basaltic shield volcanoes, the largest of which is Unda Hararo,
occupy the center of the complex. The dominant part of the complex
lies to the south, where the Gumatmali-Gablaytu fissure system is
located. Voluminous fluid lava flows issued from these NNW-trending
fissures, and solidified lava lakes occupy two large craters. Lava
flows from the Gablaytu and Manda shield volcanoes overlie 8000-year-
old sediments. Hot springs and fumaroles occur around Daorre lake. The
first historical eruption from Manda Hararo produced fissure-fed lava
flows in 2007.

Map

Sources: Simon Carn, Hawai'i Institute of Geophysics and Planetology
(HIGP) MODIS Thermal Alerts System, guardian.co.uk Science Blog

Manda Hararo Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

According to news articles, PHIVOLCS implemented increased monitoring
of Mayon after a recent rise in seismicity. Incandescence in the
crater and a slight increase in sulfur dioxide gas output over
background levels were also noted. The Alert Level remained at 1 (on a
scale of 0-5). The 7-km Extended Danger Zone (EDZ) on the SE flank and
the 6-km Permanent Danger Zone (PDZ) in all other areas remained in
effect.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: GMA News

Mayon Information from the Global Volcanism Program

SAN MIGUEL El Salvador 13.434°N, 88.269°W; summit elev. 2130 m

Servicio Nacional de Estudios Territoriales (SNET) reported that
seismic amplitude from San Miguel increased for a period of time
between 0500 and 1400 on 6 July. Seismicity remained elevated above
background levels on 7 July.

Geologic Summary. The symmetrical cone of San Miguel volcano, one of
the most active in El Salvador, rises from near sea level to form one
of the country's most prominent landmarks. A broad, deep crater that
has been frequently modified by historical eruptions (recorded since
the early 16th century) caps the truncated summit of the towering
volcano, which is also known locally as Chaparrastique. Radial
fissures on the flanks of the basaltic volcano have fed a series of
fresh lava flows, including several erupted during the 17th-19th
centuries that reached beyond the base of the volcano on the N, W, and
SE sides. The SE-flank lava flows are the largest and form broad
sparsely vegetated lava fields.

Map

Source: Servicio Nacional de Estudios Territoriales (SNET)

San Miguel Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that an intense thermal anomaly from Sarychev Peak was

detected on satellite imagery during 1-6 July. Gas-and-steam plumes
were seen almost daily and drifted 20-75 km NW, NE, and SE. Plumes
rose to altitudes of 1.5-3 km (4,900-10,000 ft) a.s.l. during 4-5
July. No large ash explosions were noted after 16 June.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
during 1-7 July ash plumes from Batu Tara rose to altitudes of 1.5-2.4
km (5,000-8,000 ft) a.s.l. and drifted 35-110 km W, NW, and N. A
thermal anomaly was detected on 3 July.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 24 June-2 July unspecified activity

from Chaitén's growing Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex

was occasionally observed, and seismicity had decreased. The Alert
Level remained at Red. Based on analysis of satellite imagery and web
camera views, the Buenos Aires VAAC reported that on 4 July an ash
plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 5 and 7 July ash plumes from Dukono rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 65 km E and 85 km NE, respectively.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 1-6 July, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha and Kupapa'u
ocean entries. Thermal anomalies detected in satellite images and
visual observations revealed active surface flows on the pali and on
the TEB flow field.

A sequence of rockfalls within the cavity on the floor of Halema'uma'u
crater began at 1338 on 30 June. The first rockfall was followed by a
loud explosion, and produced a M 2.4 equivalent earthquake felt at HVO
and the adjacent Jaggar Museum. The gas plume turned brown for several
minutes. Several more rockfall signals were detected by the seismic
network; two more were felt locally. Booming sounds also accompanied
several of the rockfalls. Chunks of the vent rim fell into the cavity.
By 1600, more than 30 rim-collapse events had been recorded by
seismometers, with a few more occurring on 1 July. Seismic tremor
amplitudes decreased by more than 50 percent. By 1800, the levels were
at their lowest values since 30 August 2007. On 1 July, scientists
observed rocky rubble within the vent and no incandescence. Sporadic
gas jetting noises were heard coming from the vent.

During 1-2 July, a few areas of incandescence were seen in the vent by
the web camera. During 2-4 July, scientists observed a small ponded
lava surface and weak spattering deep within the vent. The sulfur

dioxide emission rate at the summit remained elevated; measurements

were 360 and 200 tonnes per day on 3 and 5 July, respectivley. The

2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KRAKATAU Indonesia 6.102°S, 105.423°E; summit elev. 813 m

Based on a pilot observation, the Darwin VAAC reported that on 3 July
an ash plume from Anak Krakatau rose to an altitude below 3 km (10,000
ft) a.s.l. Ash was not detected on satellite imagery.

Geologic Summary. Renowned Krakatau volcano lies in the Sunda Strait
between Java and Sumatra. Collapse of the ancestral Krakatau edifice,
perhaps in 416 AD, resulted in a 7-km-wide caldera. Remnants of this
volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan
and Perbuwatan volcanoes were formed, coalescing to create the
pre-1883 Krakatau Island. Caldera collapse during the catastrophic
1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only
a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau
(Child of Krakatau), constructed within the 1883 caldera at a point

between the former cones of Danan and Perbuwatan, has been the site of
frequent eruptions since 1927.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Krakatau Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 3 July an ash plume from Rabaul caldera's Tavurvur cone rose to an
altitude of 4.3 km (14,000 ft) a.s.l. and drifted 45 km N. On 7 July,

an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and

drifted less than 30 km SE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 2-4
and 6-7 July explosions from Sakura-jima sometimes produced plumes
that rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. The
plumes drifted N, NE, E, and SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 2 July lahars descended the Nimá I and Nimá
II rivers on the S flank of Santa María's Santiaguito lava dome
complex, carrying tree branches and blocks 50-75 cm in diameter. The
lahars were 15 and 20 m wide. On 6 July, explosions produced ash
plumes that rose to altitudes of 2.8-3.2 km (9,200-10,500 ft) a.s.l.
and drifted W.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 25 June-3 July seismic activity from
Shiveluch was above background levels. Pyroclastic flows were noted on
25 and 26 June. Based on interpretations of seismic data, ash plumes
possibly rose to an altitude of 8.1 km (26,600 ft) a.s.l. during 25-30
June, and steam-and-gas plumes with some ash content were emitted

during the reporting period. Analysis of satellite imagery revealed a

daily thermal anomaly over the lava dome and ash plumes that drifted
97 km NE on 26 June. The Level of Concern Color Code remained at

Orange. Based on analysis of satellite imagery and information from

KEMSD, the Tokyo VAAC reported that on 3 and 5 July eruptions produced
plumes that rose to altitudes of 4.9-5.5 km (16,000-18,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion

from Suwanose-jima on 6 July. Details of a possible resultant ash
plume were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that inclement weather often prevented observations of
Tungurahua during 1-7 July; steam-and-ash plumes rose 1 km above the
summit and drifted WSW on 1 July. Ashfall was reported in areas to the
SW on 2 July. During 2 and 5-7 July, lahars that descended SW and W
drainages carrying blocks up to 40 cm in diameter.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

Based on a pilot observation, the Buenos Aires VAAC reported that on 4
July an ash plume from Ubinas rose to altitudes of 6.7-9.1 km
(22,000-30,000 ft) a.s.l. and drifted NE. Ash was not detected on
satellite imagery.

Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of
Ubinas, Peru's most active volcano, gives it a truncated appearance.
Ubinas is the northernmost of three young volcanoes located along a
regional structural lineament about 50 km behind the main volcanic
front of Peru. The upper slopes of the stratovolcano, composed
primarily of Pleistocene andesitic lava flows, steepen to nearly 45
degrees. The steep-walled, 150-m-deep summit caldera contains an ash
cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-
avalanche deposits from the collapse of the SE flank of Ubinas extend
10 km from the volcano. Widespread Plinian pumice-fall deposits from
Ubinas include some of Holocene age. Holocene lava flows are visible
on the volcano's flanks, but historical activity, documented since the
16th century, has consisted of intermittent minor explosive eruptions.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Ubinas Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

1 July-7 July 2009

New Activity/Unrest:

| Manda Hararo, Northeastern Africa
| Mayon, Luzon
| San Miguel, El Salvador
| Sarychev Peak, Matua Island

This page is updated on Wednesdays, please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between

the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

MANDA HARARO Northeastern Africa 12.17°N, 40.82°E; summit elev. 600+ m

A large sulfur dioxide plume and several thermal anomalies from Manda
Hararo were detected in satellite imagery during 28-30 June. Thermal
anomalies detected in satellite imagery indicated a surface lava flow
in the Karbahi region. Karbahi is a graben area with numerous active
faults, fissures, and basalt flows, NW of the center of the broad
Manda Hararo volcanic complex. Preliminary data suggested that the
eruption was larger than the previous eruption in August 2007. On 8
July, a scientist that visited the area reported fresh lava flows, an
eruptive fissure that was about 5 km long, and gas emitting from
multiple cones.

Geologic Summary. The southernmost axial range of western Afar, the
Manda Hararo complex is located in the Kalo plain, SSE of Dabbahu
volcano. The massive complex is 105 km long and 20-30 km wide, and
represents an uplifted segment of a mid-ocean ridge spreading center.
A small basaltic shield volcano is located at the northern end of the
complex, south of which is an area of abundant fissure-fed lava flows.
Two basaltic shield volcanoes, the largest of which is Unda Hararo,
occupy the center of the complex. The dominant part of the complex
lies to the south, where the Gumatmali-Gablaytu fissure system is
located. Voluminous fluid lava flows issued from these NNW-trending
fissures, and solidified lava lakes occupy two large craters. Lava
flows from the Gablaytu and Manda shield volcanoes overlie 8000-year-
old sediments. Hot springs and fumaroles occur around Daorre lake. The
first historical eruption from Manda Hararo produced fissure-fed lava
flows in 2007.

Map

Sources: Simon Carn, Hawai'i Institute of Geophysics and Planetology
(HIGP) MODIS Thermal Alerts System, guardian.co.uk Science Blog

Manda Hararo Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

According to news articles, PHIVOLCS implemented increased monitoring
of Mayon after a recent rise in seismicity. Incandescence in the
crater and a slight increase in sulfur dioxide gas output over
background levels were also noted. The Alert Level remained at 1 (on a
scale of 0-5). The 7-km Extended Danger Zone (EDZ) on the SE flank and
the 6-km Permanent Danger Zone (PDZ) in all other areas remained in
effect.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: GMA News

Mayon Information from the Global Volcanism Program

SAN MIGUEL El Salvador 13.434°N, 88.269°W; summit elev. 2130 m

Servicio Nacional de Estudios Territoriales (SNET) reported that
seismic amplitude from San Miguel increased for a period of time
between 0500 and 1400 on 6 July. Seismicity remained elevated above
background levels on 7 July.

Geologic Summary. The symmetrical cone of San Miguel volcano, one of
the most active in El Salvador, rises from near sea level to form one
of the country's most prominent landmarks. A broad, deep crater that
has been frequently modified by historical eruptions (recorded since
the early 16th century) caps the truncated summit of the towering
volcano, which is also known locally as Chaparrastique. Radial
fissures on the flanks of the basaltic volcano have fed a series of
fresh lava flows, including several erupted during the 17th-19th
centuries that reached beyond the base of the volcano on the N, W, and
SE sides. The SE-flank lava flows are the largest and form broad
sparsely vegetated lava fields.

Map

Source: Servicio Nacional de Estudios Territoriales (SNET)

San Miguel Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that an intense thermal anomaly from Sarychev Peak was

detected on satellite imagery during 1-6 July. Gas-and-steam plumes
were seen almost daily and drifted 20-75 km NW, NE, and SE. Plumes
rose to altitudes of 1.5-3 km (4,900-10,000 ft) a.s.l. during 4-5
July. No large ash explosions were noted after 16 June.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
during 1-7 July ash plumes from Batu Tara rose to altitudes of 1.5-2.4
km (5,000-8,000 ft) a.s.l. and drifted 35-110 km W, NW, and N. A
thermal anomaly was detected on 3 July.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 24 June-2 July unspecified activity

from Chaitén's growing Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex

was occasionally observed, and seismicity had decreased. The Alert
Level remained at Red. Based on analysis of satellite imagery and web
camera views, the Buenos Aires VAAC reported that on 4 July an ash
plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 5 and 7 July ash plumes from Dukono rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 65 km E and 85 km NE, respectively.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 1-6 July, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha and Kupapa'u
ocean entries. Thermal anomalies detected in satellite images and
visual observations revealed active surface flows on the pali and on
the TEB flow field.

A sequence of rockfalls within the cavity on the floor of Halema'uma'u
crater began at 1338 on 30 June. The first rockfall was followed by a
loud explosion, and produced a M 2.4 equivalent earthquake felt at HVO
and the adjacent Jaggar Museum. The gas plume turned brown for several
minutes. Several more rockfall signals were detected by the seismic
network; two more were felt locally. Booming sounds also accompanied
several of the rockfalls. Chunks of the vent rim fell into the cavity.
By 1600, more than 30 rim-collapse events had been recorded by
seismometers, with a few more occurring on 1 July. Seismic tremor
amplitudes decreased by more than 50 percent. By 1800, the levels were
at their lowest values since 30 August 2007. On 1 July, scientists
observed rocky rubble within the vent and no incandescence. Sporadic
gas jetting noises were heard coming from the vent.

During 1-2 July, a few areas of incandescence were seen in the vent by
the web camera. During 2-4 July, scientists observed a small ponded
lava surface and weak spattering deep within the vent. The sulfur

dioxide emission rate at the summit remained elevated; measurements

were 360 and 200 tonnes per day on 3 and 5 July, respectivley. The

2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KRAKATAU Indonesia 6.102°S, 105.423°E; summit elev. 813 m

Based on a pilot observation, the Darwin VAAC reported that on 3 July
an ash plume from Anak Krakatau rose to an altitude below 3 km (10,000
ft) a.s.l. Ash was not detected on satellite imagery.

Geologic Summary. Renowned Krakatau volcano lies in the Sunda Strait
between Java and Sumatra. Collapse of the ancestral Krakatau edifice,
perhaps in 416 AD, resulted in a 7-km-wide caldera. Remnants of this
volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan
and Perbuwatan volcanoes were formed, coalescing to create the
pre-1883 Krakatau Island. Caldera collapse during the catastrophic
1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only
a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau
(Child of Krakatau), constructed within the 1883 caldera at a point

between the former cones of Danan and Perbuwatan, has been the site of
frequent eruptions since 1927.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Krakatau Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 3 July an ash plume from Rabaul caldera's Tavurvur cone rose to an
altitude of 4.3 km (14,000 ft) a.s.l. and drifted 45 km N. On 7 July,

an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and

drifted less than 30 km SE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 2-4
and 6-7 July explosions from Sakura-jima sometimes produced plumes
that rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. The
plumes drifted N, NE, E, and SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 2 July lahars descended the Nimá I and Nimá
II rivers on the S flank of Santa María's Santiaguito lava dome
complex, carrying tree branches and blocks 50-75 cm in diameter. The
lahars were 15 and 20 m wide. On 6 July, explosions produced ash
plumes that rose to altitudes of 2.8-3.2 km (9,200-10,500 ft) a.s.l.
and drifted W.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 25 June-3 July seismic activity from
Shiveluch was above background levels. Pyroclastic flows were noted on
25 and 26 June. Based on interpretations of seismic data, ash plumes
possibly rose to an altitude of 8.1 km (26,600 ft) a.s.l. during 25-30
June, and steam-and-gas plumes with some ash content were emitted

during the reporting period. Analysis of satellite imagery revealed a

daily thermal anomaly over the lava dome and ash plumes that drifted
97 km NE on 26 June. The Level of Concern Color Code remained at

Orange. Based on analysis of satellite imagery and information from

KEMSD, the Tokyo VAAC reported that on 3 and 5 July eruptions produced
plumes that rose to altitudes of 4.9-5.5 km (16,000-18,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion

from Suwanose-jima on 6 July. Details of a possible resultant ash
plume were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that inclement weather often prevented observations of
Tungurahua during 1-7 July; steam-and-ash plumes rose 1 km above the
summit and drifted WSW on 1 July. Ashfall was reported in areas to the
SW on 2 July. During 2 and 5-7 July, lahars that descended SW and W
drainages carrying blocks up to 40 cm in diameter.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

Based on a pilot observation, the Buenos Aires VAAC reported that on 4
July an ash plume from Ubinas rose to altitudes of 6.7-9.1 km
(22,000-30,000 ft) a.s.l. and drifted NE. Ash was not detected on
satellite imagery.

Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of
Ubinas, Peru's most active volcano, gives it a truncated appearance.
Ubinas is the northernmost of three young volcanoes located along a
regional structural lineament about 50 km behind the main volcanic
front of Peru. The upper slopes of the stratovolcano, composed
primarily of Pleistocene andesitic lava flows, steepen to nearly 45
degrees. The steep-walled, 150-m-deep summit caldera contains an ash
cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-
avalanche deposits from the collapse of the SE flank of Ubinas extend
10 km from the volcano. Widespread Plinian pumice-fall deposits from
Ubinas include some of Holocene age. Holocene lava flows are visible
on the volcano's flanks, but historical activity, documented since the
16th century, has consisted of intermittent minor explosive eruptions.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Ubinas Information from the Global Volcanism Program

Last Post

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Jul 15, 2009, 7:42:00 PM7/15/09

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SI / USGS Weekly Volcanic Activity Report

8 July-14 July 2009

New Activity/Unrest:
| Manda Hararo, Northeastern Africa
| Mayon, Luzon
| San Miguel, El Salvador
| Sarychev Peak, Matua Island

| Shishaldin, Fox Islands

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Fuego, Guatemala
| Kilauea, Hawaii (USA)
| Pacaya, Guatemala

| Rabaul, New Britain
| Sakura-jima, Kyushu

| Shiveluch, Central Kamchatka (Russia)

This page is updated on Wednesdays, please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

MANDA HARARO Northeastern Africa 12.17°N, 40.82°E; summit elev. 600+ m

A large sulfur dioxide plume and several thermal anomalies from Manda

Hararo that were detected in satellite imagery during 28-30 June
prompted a science team to visit the area on 4 July. After conducting
ground-based and aerial observations for approximately 2 hours, they
reported that the eruption occurred near the August 2007 eruption
site, and was possibly bigger than that event. No active lava effusion
was seen, but steaming was observed from the 4-5 km-long fissure that,
because of high temperatures, had to be observed from a distance. They
also saw new predominantly 'a'a lava flows that were 2-3 m thick. The
fissure was lined with scoria ramparts 30-50 m high. Temperature
measurements taken with a FLIR (Forward Looking Infrared Radiometer)
indicated that the lava flow had cooled significantly with
temperatures between 30 and 120 degrees Celsius at the surface. A
maximum temperature of 238 degrees Celsius was measured during aerial
observations.

Geologic Summary. The southernmost axial range of western Afar, the
Manda Hararo complex is located in the Kalo plain, SSE of Dabbahu
volcano. The massive complex is 105 km long and 20-30 km wide, and
represents an uplifted segment of a mid-ocean ridge spreading center.
A small basaltic shield volcano is located at the northern end of the
complex, south of which is an area of abundant fissure-fed lava flows.
Two basaltic shield volcanoes, the largest of which is Unda Hararo,
occupy the center of the complex. The dominant part of the complex
lies to the south, where the Gumatmali-Gablaytu fissure system is
located. Voluminous fluid lava flows issued from these NNW-trending
fissures, and solidified lava lakes occupy two large craters. Lava
flows from the Gablaytu and Manda shield volcanoes overlie 8000-year-
old sediments. Hot springs and fumaroles occur around Daorre lake. The
first historical eruption from Manda Hararo produced fissure-fed lava
flows in 2007.

Map

Sources: Gezahegn Yirgu, Addis Ababa University (AAU), Simon Carn

Manda Hararo Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

PHIVOLCS reported that a "cone-shaped pile of hot, steaming old
rocks," possibly from a previous eruption of Mayon, were seen during
an overflight on 8 July and may be the source of recent summit
incandescence. On 9 July, a leveling survey revealed that 1 cm of
uplift previously measured during 15-22 June had been sustained.
Incandescence at the summit crater had also intensified and was
visible from the Lignon Hill Observatory (about 11 km SSE) without the
aid of telescopes. Steam emissions were also noted. On 10 July,
PHIVOLCS raised the Alert Level for Mayon from 1 (low level unrest) to
2 (moderate unrest) on a scale of 0-5.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Mayon Information from the Global Volcanism Program

SAN MIGUEL El Salvador 13.434°N, 88.269°W; summit elev. 2130 m

Servicio Nacional de Estudios Territoriales (SNET) reported that the
amplitude of seismic events from San Miguel had decreased during 9-13
July, but RSAM values remained above the background average. Access to
areas within a 2-km-radius was restricted.

Geologic Summary. The symmetrical cone of San Miguel volcano, one of
the most active in El Salvador, rises from near sea level to form one
of the country's most prominent landmarks. A broad, deep crater that
has been frequently modified by historical eruptions (recorded since
the early 16th century) caps the truncated summit of the towering
volcano, which is also known locally as Chaparrastique. Radial
fissures on the flanks of the basaltic volcano have fed a series of
fresh lava flows, including several erupted during the 17th-19th
centuries that reached beyond the base of the volcano on the N, W, and
SE sides. The SE-flank lava flows are the largest and form broad
sparsely vegetated lava fields.

Map

Source: Servicio Nacional de Estudios Territoriales (SNET)

San Miguel Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

Based on analyses of satellite imagery, SVERT reported that diffuse
gas-and-steam plumes from Sarychev Peak were seen on satellite imagery
during 8-10 and 12 July. Plumes drifted 15 km E on 8 July. The plumes
seen on 9 July drifted 50 km E and may have contained some ash. Gas-
and-ash plumes drifted 40 km E on 13 July and 25 km W and NW on 14
July.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

SHISHALDIN Fox Islands 54.756°N, 163.97°W; summit elev. 2857 m

On 10 July, AVO reported that a distinct thermal anomaly in
Shishaldin's summit crater observed intermittently since January 2009
became more intense during the previous month. AVO raised the Aviation
Color Code to Yellow and the Volcano Alert Level to Advisory. AVO also
noted that seismicity had not increased, deformation was unchanged,
and satellite observations showed no significant sulfur dioxide gas
emissions. Some reports of steaming from the summit crater were
received.

Geologic Summary. The beautifully symmetrical volcano of Shishaldin is
the highest and one of the most active volcanoes of the Aleutian
Islands. The 2,857-m-high, glacier-covered volcano is the westernmost
of three large stratovolcanoes along an E-W line in the eastern half
of Unimak Island. Constructed atop an older glacially dissected
volcano, Shishaldin is Holocene in age and largely basaltic in
composition. Remnants of an older ancestral volcano are exposed on the
W and NE sides at 1,500-1,800 m elevation. Shishaldin contains over
two dozen pyroclastic cones on its NW flank, which is blanketed by
massive aa lava flows. Frequent explosive activity, primarily
consisting of Strombolian ash eruptions from the small summit crater,
sometimes producing lava flows, have been recorded since the 18th
century.

Map

Source: Alaska Volcano Observatory (AVO)

Shishaldin Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analysis of satellite imagery, the Darwin VAAC reported that

on 8 July ash plumes from Batu Tara rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 55 km W and NW. During 12-14 July, ash
plumes rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted
25-55 km W, NW, and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views from the S, SERNAGEOMIN reported that during
3-8 July gas-and-ash plumes rose 1.5 km from Chaitén's growing Domo

Nuevo 1 and Domo Nuevo 2 lava-dome complex. Collapses originating from

unstable slopes generated block-and-ash flows, particularly in the W
area of the complex. The Alert Level remained at Red. Based on web
camera views and a SIGMET notice, the Buenos Aires VAAC reported that
on 10 July ash plumes rose to altitudes of 1.8-2.4 km (6,000-8,000 ft)
a.s.l. and drifted NE. A thermal anomaly was also seen in satellite
imagery on 11 June.

Geologic Summary. Chaitén is a small, glacier-free caldera with a

Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analysis of satellite imagery, the Darwin VAAC reported that

on 8 July ash plumes from Dukono rose to an altitude of 2.4 km (8,000
ft) a.s.l. and drifted 85 km NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 10 and 14 July, INSIVUMEH reported that explosions from Fuego
produced ash plumes that rose to altitudes of 4.1-4.6 km
(13,500-15,100 ft) a.s.l. and drifted 10-15 km W and SW. Some
explosions were accompanied by rumbling noises and shock waves.
Incandescent material was ejected 75 m high and incandescent
avalanches descended several ravines. Fumarolic plumes rose 100 m and
drifted S and SW.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 8-14 July, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha and Kupapa'u
ocean entries. Thermal anomalies detected in satellite images and
visual observations revealed active surface flows on the pali and on

the TEB flow field. Explosions from both ocean entries were reported
on 8 July; strong explosions ejected incandescent tephra up to 20 m
high at the Waikupanaha entry.

The vent in Halema'uma'u crater continued to produce a predominantly

white plume that drifted mainly SW. No lava or incandescence from the
crater had been seen since a "deflation-inflation" event on 4 July.
Small amounts of ash-sized tephra were retrieved from collection bins
placed near the plume during the reporting period. The sulfur dioxide

emission rate at the summit remained elevated; measurements were

between 300 and 400 tonnes per day during 8-10 and 13 July. The

2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 10 and 14 July, INSIVUMEH reported that fumarolic plumes from
Pacaya's MacKenney drifted S and gas plumes rose 300 m. Multiple lava
flows 150-600 m long traveled SW.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 3-9 July incandescence from Rabaul caldera's
Tavurvur cone was visible at night. Steam plumes rose 1.5 km above the
crater. Based on analysis of satellite imagery, the Darwin VAAC
reported that during 9-10 July ash plumes rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 20-40 km NW, N, and NE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 8
and 10-15 July explosions from Sakura-jima sometimes produced plumes
that rose to altitudes of 1.8-3.4 km (6,000-11,000 ft) a.s.l. The
plumes drifted NE and E.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 3-10 July seismic activity from Shiveluch
was above background levels. Based on interpretations of seismic data,
ash plumes possibly rose to an altitude of 5.3 km (13,400 ft) a.s.l.
on 2 and 4 July, and steam-and-gas plumes with some ash content were
emitted during the reporting period. On 3 July, a gas-and-steam plume
seen on a video camera rose to an altitude of 3.3 km (10,800 ft)
a.s.l. Analysis of satellite imagery revealed a daily thermal anomaly
over the lava dome. The Level of Concern Color Code remained at
Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

BDR529

unread,

Jul 21, 2009, 7:35:15 AM7/21/09

to

And what has this got to do with the daily price of fish?

Last Post wrote:
> SI / USGS Weekly Volcanic Activity Report
>
> 8 July-14 July 2009
>
> New Activity/Unrest:
> | Manda Hararo, Northeastern Africa
> | Mayon, Luzon
> | San Miguel, El Salvador
> | Sarychev Peak, Matua Island
> | Shishaldin, Fox Islands
>
> Ongoing Activity:
>
> | Batu Tara, Komba Island (Indonesia)

> | Chait�n, Southern Chile

> 3-8 July gas-and-ash plumes rose 1.5 km from Chait�n's growing Domo

> Nuevo 1 and Domo Nuevo 2 lava-dome complex. Collapses originating from
> unstable slopes generated block-and-ash flows, particularly in the W
> area of the complex. The Alert Level remained at Red. Based on web
> camera views and a SIGMET notice, the Buenos Aires VAAC reported that
> on 10 July ash plumes rose to altitudes of 1.8-2.4 km (6,000-8,000 ft)
> a.s.l. and drifted NE. A thermal anomaly was also seen in satellite
> imagery on 11 June.
>

> Geologic Summary. Chait�n is a small, glacier-free caldera with a
> Holocene lava dome located 10 km NE of the town of Chait�n on the Gulf

> of Corcovado. A pyroclastic-surge and pumice deposit considered to
> originate from the eruption that formed the elliptical 2.5 x 4 km wide
> summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
> high obsidian lava dome occupies much of the caldera floor. Obsidian
> cobbles from this dome found in the Blanco River are the source of
> prehistorical artifacts from archaeological sites along the Pacific
> coast as far as 400 km away from the volcano to the north and south.
> The caldera is breached on the SW side by a river that drains to the

> bay of Chait�n, and the high point on its southern rim reaches 1122 m.
>
> Map
>
> Sources: Servicio Nacional de Geolog�a y Miner�a (SERNAGEOMIN), Buenos

> Aires Volcanic Ash Advisory Center (VAAC)
>

> Chait�n Information from the Global Volcanism Program

> Geologic Summary. Volc�n Fuego, one of Central America's most active

Last Post

unread,

Jul 21, 2009, 8:05:49 AM7/21/09

to

On Jul 21, 7:35 am, BDR529 <jake> wrote:
> And what has this got to do with the daily price of fish?

•• For Jackass Jake, the idiot top poster:
It has nothing "to do with the daily price of
fish" but it has a whole lot to do with the
climate.

> Last Post wrote:
> > SI / USGS Weekly Volcanic Activity Report
>
> > 8 July-14 July 2009
>
> > New Activity/Unrest:
> > | Manda Hararo, Northeastern Africa
> > | Mayon, Luzon
> > | San Miguel, El Salvador
> > | Sarychev Peak, Matua Island
> > | Shishaldin, Fox Islands
>
> > Ongoing Activity:
>
> > | Batu Tara, Komba Island (Indonesia)

> > | Chaitén, Southern Chile

Last Post

unread,

Jul 21, 2009, 8:48:00 AM7/21/09

to

On Jul 21, 8:05 am, Last Post <last_p...@primus.ca> wrote:
> On Jul 21, 7:35 am, BDR529 <jake> wrote:
>
> > And what has this got to do with the daily price of fish?
>
> •• For Jackass Jake, the idiot top poster:
> It has nothing "to do with the daily price of
> fish" but it has a whole lot to do with the
> climate.

•• BTW: a couple of biggies went silent last week including
| Krakatau, Indonesia
| Santa María, Guatemala

 | Suwanose-jima, Ryukyu Islands (Japan)
 | Tungurahua, Ecuador
| Ubinas, Perú

•• There will be an updated list tomorrow 1800 ET

Last Post

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Jul 22, 2009, 4:24:22 PM7/22/09

to

SI / USGS Weekly Volcanic Activity Report

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

15 July-21 July 2009

New Activity/Unrest:

| Sakura-jima, Kyushu
| San Miguel, El Salvador

Ongoing Activity:

| Bagana, Bougainville
| Barren Island, Andaman Is

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the

GVP Home Page for news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, analyses of satellite imagery, and
pilot observations, the Tokyo VAAC reported that during 15-21 July
explosions from Sakura-jima's Showa crater occasionally produced
plumes that rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l.
Plumes were observed drifting SW, N, and NE. On 19 July, JMA raised
the Alert Level from 2 to 3 (on a scale of 1-5). They noted increased
frequency of explosive eruptions since late June, and shock waves that
were detected on 18 and 19 July.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash
Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SAN MIGUEL El Salvador 13.434°N, 88.269°W; summit elev. 2130 m

On 20 July, Servicio Nacional de Estudios Territoriales (SNET)

reported that the amplitude of seismic events from San Miguel had

decreased to normal or background levels. Access to areas within a 2-
km-radius continued to be restricted.

Geologic Summary. The symmetrical cone of San Miguel volcano, one of
the most active in El Salvador, rises from near sea level to form one
of the country's most prominent landmarks. A broad, deep crater that
has been frequently modified by historical eruptions (recorded since
the early 16th century) caps the truncated summit of the towering
volcano, which is also known locally as Chaparrastique. Radial
fissures on the flanks of the basaltic volcano have fed a series of
fresh lava flows, including several erupted during the 17th-19th
centuries that reached beyond the base of the volcano on the N, W, and
SE sides. The SE-flank lava flows are the largest and form broad
sparsely vegetated lava fields.

Map

Source: Servicio Nacional de Estudios Territoriales (SNET)

San Miguel Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 19 July an ash plume from Bagana rose to an altitude of 1.8 km
(6,000 ft) a.s.l. and drifted 100 km NW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BARREN ISLAND Andaman Is 12.278°N, 93.858°E; summit elev. 354 m

Based on analysis of satellite imagery, the Darwin VAAC reported that

during 19-20 July an ash plume from Barren Island rose to an altitude
of 1.5 km (5,000 ft) a.s.l. and drifted 45-65 km NE.

Geologic Summary. Barren Island, a possession of India in the Andaman
Sea about 135 km NE of Port Blair in the Andaman Islands, is the only
historically active volcano along the N-S-trending volcanic arc
extending between Sumatra and Burma (Myanmar). The 354-m-high island
is the emergent summit of volcano that rises from a depth of about
2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-
km-wide caldera with walls 250-350 m high. The caldera, which is open
to the sea on the W, was created during a major explosive eruption in
the late Pleistocene that produced pyroclastic-flow and -surge
deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course
of historical eruptions. Lava flows fill much of the caldera floor and
have reached the sea along the western coast during historical
eruptions.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Barren Island Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 15-18 July ash plumes from Batu Tara rose to an altitude of 1.5
km (5,000 ft) a.s.l. and drifted 20-55 km in multiple directions.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views from the S, SERNAGEOMIN reported that during

8-15 July gas-and-ash plumes rose 1.2 km from Chaitén's growing Domo

Nuevo 1 and Domo Nuevo 2 lava-dome complex. Collapses originating from
unstable slopes generated block-and-ash flows, particularly in the W
area of the complex. The Alert Level remained at Red. Based on web

camera views, analyses of satellite imagery, and a SIGMET notice, the
Buenos Aires VAAC reported that during 16, 19, and 21 July ash plumes

rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted

NNE, SE, and SSW. Thermal anomalies were detected in satellite imagery
on 16 and 19 July.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf

of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the

bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

EGON Flores Island (Indonesia) 8.67°S, 122.45°E; summit elev. 1703 m

CVGHM reported that the Alert Level for Egon was lowered to 1 (on a
scale of 1-4) on 16 July due to the continued decrease in earthquake
activity since 12 May. Small steam plumes were occasionally visible
when the weather was clear.

Geologic Summary. Gunung Egon volcano sits astride the narrow waist of
eastern Flores Island. The barren, sparsely vegetated summit region
has a 350-m-wide, 200-m-deep crater that sometimes contains a lake.
Other small crater lakes occur on the flanks of the 1,703-m-high
volcano. A lava dome forms the southern 1,671-m-high summit. Reports
of historical eruptive activity are inconclusive. A column of "smoke"
was often observed above the summit during 1888-1891 and in 1892.
Strong "smoke" emission in 1907 reported by Sapper (1917) was
considered by the Catalog of Active Volcanoes of the World (Neumann
van Padang, 1951) to be an historical eruption, but Kemmerling (1929)
noted that this was likely confused with an eruption on the same date
and time from Lewotobi Lakilaki volcano.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Egon Information from the Global Volcanism Program

IBU Halmahera 1.488°N, 127.63°E; summit elev. 1325 m

CVGHM reported that white and gray plumes from Ibu rose 600 m above
the crater rim prior to 11 July and 400 m above the crater afterwards.
Ashfall was reported in nearby areas, within a 3-km-radius of Ibu.
Based on information from the Gamsungi observation post and seismic
data, CVGHM lowered the Alert Level on 16 July from 3 to 2 (on a scale
of 1-4). Residents and tourists were not permitted within 2 km of the
crater.

Geologic Summary. The truncated summit of Gunung Ibu stratovolcano
along the NW coast of Halmahera Island has large nested summit
craters. The inner crater, 1 km wide and 400 m deep, contained several
small crater lakes through much of historical time. The outer crater,
1.2 km wide, is breached on the north side, creating a steep-walled
valley. A large parasitic cone is located ENE of the summit. A smaller
one to the WSW has fed a lava flow down the western flank. A group of
maars is located below the northern and western flanks of the volcano.
Only a few eruptions have been recorded from Ibu in historical time,
the first a small explosive eruption from the summit crater in 1911.
An eruption producing a lava dome that eventually covered much of the
floor of the inner summit crater began in December 1998.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Ibu Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 15-20 July, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha and Kupapa'u
ocean entries. Thermal anomalies detected in satellite images and

visual observations revealed active surface flows at several locations
on the pali, and on the TEB flow field. A structure in the abandoned
Royal Gardens subdivision was destroyed on 16 July. Explosions from
the Waikupanaha ocean entry were reported on 17 July. Lava was not
seen entering the ocean on 21 July.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted mainly SW. No lava or incandescence from the crater
had been seen since a "deflation-inflation" event on 4 July. Small

amounts of ash-sized "rock dust" were retrieved from collection bins

placed near the plume during the reporting period. The sulfur dioxide

emission rate at the summit remained elevated; measurements were 400
and 1,100 tonnes per day on 17 and 20 July, respectively. The

2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

MAKIAN Halmahera 0.32°N, 127.40°E; summit elev. 1357 m

CVGHM reported that on 16 July the Alert Level for Makian was lowered
from 2 to 1 (on a scale of 1-4) because no visual changes or increased
seismicity were noted. Residents and tourists were not permitted to
climb Makian.

Geologic Summary. Makian volcano forms a 10-km-wide island near the
southern end of a chain of volcanic islands off the W coast of
Halmahera and has been the source of infrequent, but violent eruptions
that have devastated villages on the island. The large 1.5-km-wide
summit crater, containing a small lake on the NE side, gives the peak
a flat-topped profile. Two prominent valleys extend to the coast from
the summit crater on the N and E sides. Four parasitic cones are found
on the western flanks. Eruption have been recorded since about 1550;
major eruptions in 1646, 1760-61, 1861-62, 1890, and 1988 caused
extensive damage and many fatalities.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Makian Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 10-21 July white and occasionally blue tinted
plumes from Rabaul caldera's Tavurvur cone rose less than 1 km above
the crater. Pale-gray ash accompanied the emissions on 13 and 15 July.
Ashfall affected Rabaul town (3-5 km NW), Ratavul (20 km SSE), and
Nonga (10 km NW). Incandescence was visible at night and roaring was
heard during 14-18 July.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

Based on analyses of satellite imagery, SVERT reported that gas-and-

steam plumes from Sarychev Peak were seen on satellite imagery during

15, 18-19, and 21 July. Plumes drifted 30-50 km W and S. Cloud cover
prevented observations during 16-17 and 20 July. Sarychev Peak does
not have a seismic network.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

SEMERU Eastern Java (Indonesia) 8.108°S, 112.92°E; summit elev. 3676 m

CVGHM reported that on 15 March an eruption from Semeru produced a
white-and-gray plume that rose 600 m above the crater. White plumes
and ash eruptions gradually ceased and seismicity decreased. From 5
May until the end of June, fog prevented visual observations. On 16
July, the Alert Level was lowered to 2 (on a scale of 1-4).

Geologic Summary. Semeru is the highest volcano on Java and one of its
most active. The symmetrical stratovolcano rises abruptly to 3,676 m
above coastal plains to the S and lies at the southern end of a
volcanic massif extending N to the Tengger caldera. Semeru has been in
almost continuous eruption since 1967. Frequent small-to-moderate
Vulcanian eruptions have accompanied intermittent lava dome extrusion,
and periodic pyroclastic flows and lahars have damaged villages below
the volcano. A major secondary lahar on 14 May 1981 caused more than
250 deaths and damaged 16 villages.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Semeru Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 10-17 July seismic activity from Shiveluch
was above background levels. On 14 July, a gas-and-steam plume seen on
a video camera rose to an altitude of 4 km (13,100 ft) a.s.l. Based on

interpretations of seismic data, ash plumes possibly rose to an

altitude of 6.5 km (21,300 ft) a.s.l. during 10, 13-14, and 16 July,

and steam-and-gas plumes with some ash content were emitted during the

reporting period. Analysis of satellite imagery revealed a daily
thermal anomaly over the lava dome, and a steam plume that drifted 19
km SW on 13 July. The Level of Concern Color Code remained at Orange.
Based on analyses of satellite imagery and information from KEMSD, the
Tokyo VAAC reported that on 17 July an eruption produced a plume that
rose to an altitude of 5.5 km (18,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on a pilot observation, the Tokyo VAAC reported that on 15 July
an ash plume from Suwanose-jima rose to an altitude of 2.1 km (7,000
ft) a.s.l. and drifted NE. Eruptions reported by the JMA during 16-17
July produced plumes that rose to altitudes of 1.5-1.8 km (5,000-6,000
ft) a.s.l. and drifted NE and W.

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Jul 29, 2009, 2:23:34 PM7/29/09

to

SI / USGS Weekly Volcanic Activity Report

22 July-28 July 2009

New Activity/Unrest:

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile

| Kilauea, Hawaii (USA)
| Nevado del Huila, Colombia

| Sangay, Ecuador
| Sarychev Peak, Matua Island

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays,
please see the GVP Home Page for news
of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that on 22 July
explosions from Sakura-jima produced plumes that rose to altitudes of
1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted E and SE. On 23 July
and 27 July pilots observed ash plumes that rose to altitudes of 2.1
and 3 km (7,000 and 10,000 ft) a.s.l. and drifted E and SW,
respectively. Explosions were reported during 24-25 and 28 July.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 17-18 and 20-24 July seismic activity from
Shiveluch was above background levels. During 17-20 and 22 July, gas-
and-steam plumes seen on a video camera rose to an altitude of 3.7 km
(12,100 ft) a.s.l. Based on interpretations of seismic data, ash
plumes possibly rose to an altitude of 5.2 km (17,000 ft) a.s.l. on
20, 21, and 22 July, and steam-and-gas plumes with some ash content
were noted on other days. Analyses of satellite imagery revealed a
large daily thermal anomaly over the lava dome, and steam plumes that
drifted as far away as 40 km on 18 and 20 July. The Level of Concern

Color Code remained at Orange.

Based on analyses of satellite imagery and information from KEMSD, the

Tokyo VAAC reported that during 23-24 and 27-28 July eruptions
produced plumes that rose to altitudes of 4.6-6.1 km (15,000-20,000
ft) a.s.l. According to news sources, an ash plume rose to an altitude
of 7 km (23,000 ft) a.s.l. late on 25 July. Increased seismicity,
powerful ash bursts, and avalanches were also reported.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC), Ria Novosti

Shiveluch Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 23 July an ash plume from Batu Tara rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 55 km W. On 27 and 28 July, ash plumes
rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted as far
away as 150 km NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views from the S, SERNAGEOMIN reported that during

16-22 July gas-and-ash plumes rose 1.5 km from Chaitén's growing Domo

Nuevo 1 and Domo Nuevo 2 lava-dome complex. Collapses originating from
unstable slopes generated block-and-ash flows, particularly in the W
area of the complex. The Alert Level remained at Red. Based on web

camera views and analyses of satellite imagery, the Buenos Aires VAAC
reported that on 28 July an ash plume rose to an altitude of 1.8 km
(6,000 ft) a.s.l. and drifted NE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 22-28 July, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex

through a lava tube system, reaching the Waikupanaha ocean entry.

Thermal anomalies detected in satellite images and visual observations

revealed active surface flows at several locations on the pali.
Explosions from the Waikupanaha ocean entry were reported on 22 July.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted mainly SW. Small amounts of ash-sized "rock dust"

were retrieved from collection bins placed near the plume during the
reporting period. The sulfur dioxide emission rate at the summit

remained elevated; measurements were 800, 500, and 950 tonnes per day
on 22, 24, and 27 July, respectively. The 2003-2007 average rate was
140 tonnes per day; between the 30 June rockfall sequence and 19 July
rates were 200-400 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that during 22-28 July four pulses of seismic
tremor from Nevado del Huila indicated explosions. Gas plumes were
seen on a web camera and during a commercial flight. On 23 July,
ashfall was reported in an area to the NW. The Alert Level remained at
III (Yellow; "changes in the behavior of volcanic activity").

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Huila Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on a pilot observation, the Washington VAAC reported that on 23
July a possible ash plume from Sangay rose to an altitude of 7.9 km
(26,000 ft) a.s.l. The plume was not identified in satellite imagery.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

Based on analyses of satellite imagery, SVERT reported that on 22 July
a gas-and-steam plume from Sarychev Peak drifted 35 km N. Cloud cover
prevented observations during 23-26 July. On 27 July, a steam-and-gas
plume possibly containing some ash rose to an altitude of 3.7 km
(12,000 ft) a.s.l. and drifted 55 km NW.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Sources: Sakhalin Volcanic Eruption Response Team (SVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Sarychev Peak Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 23-24 July. Details of possible resultant ash
plumes were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

BDR529

unread,

Aug 1, 2009, 3:28:16 AM8/1/09

to

Last Post wrote:
> On Jul 21, 7:35 am, BDR529 <jake> wrote:
>> And what has this got to do with the daily price of fish?
>

> ï¿½ï¿½ For Jackass Jake, the idiot top poster:

> It has nothing "to do with the daily price of
> fish" but it has a whole lot to do with the
> climate.

If it hasn't got anything to do with the price of fish then probably it
is worthless.

Q

>
>> Last Post wrote:
>>> SI / USGS Weekly Volcanic Activity Report
>>> 8 July-14 July 2009
>>> New Activity/Unrest:
>>> | Manda Hararo, Northeastern Africa
>>> | Mayon, Luzon
>>> | San Miguel, El Salvador
>>> | Sarychev Peak, Matua Island
>>> | Shishaldin, Fox Islands
>>> Ongoing Activity:
>>> | Batu Tara, Komba Island (Indonesia)

>>> | Chaitï¿½n, Southern Chile

--
Our Lady of Blessed Acceleration, don't fail me now!

Last Post

unread,

Aug 5, 2009, 7:50:18 PM8/5/09

to

SI / USGS Weekly Volcanic Activity Report

29 July-4 August 2009

New Activity/Unrest:

| Kizimen, Eastern Kamchatka
| Kliuchevskoi, Central Kamchatka (Russia)

Ongoing Activity:
| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile

| Colima, México
| Ebeko, Paramushir Island
| Fuego, Guatemala
| Galeras, Colombia

| Kilauea, Hawaii (USA)
| Nevado del Huila, Colombia

| Pacaya, Guatemala
| Rabaul, New Britain
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KIZIMEN Eastern Kamchatka 55.130°N, 160.32°E; summit elev. 2376 m

On 31 July, KVERT reported that seismic activity from Kizimen had
increased since 11 July. Several tens of shallow earthquakes per day
were detected. The Level of Concern Color Code was raised to Yellow.

Geologic Summary. Kizimen is an isolated, conical stratovolcano that
is morphologically similar to Mount St. Helens prior to its 1980
eruption. The summit of Kizimen consists of overlapping lava domes,
and blocky lava flows descend the flanks of the volcano, which is the
westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-
m-high Kizimen was formed during four eruptive cycles beginning about
12,000 years ago and lasting 2,000-3,500 years. The largest eruptions
took place about 10,000 and 8300-8400 years ago, and three periods of
longterm lava-dome growth have occurred. The latest eruptive cycle
began about 3,000 years ago with a large explosion and was followed by
lava-dome growth lasting intermittently about 1,000 years. An
explosive eruption about 1,100 years ago produced a lateral blast and
created a 1.0 x 0.7 km wide crater breached to the NE, inside which a
small lava dome (the fourth at Kizimen) has grown. A single explosive
eruption, during 1927-28, has been recorded in historical time.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kizimen Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

On 2 August, KVERT reported that seismic activity from Kliuchevskoi
had gradually increased since 30 July, and continuous seismic tremor
was detected. A strong thermal anomaly was seen in satellite imagery
at night. The Level of Concern Color Code was raised to Yellow.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 29-31 July ash plumes from Batu Tara rose to an altitude of 1.5 km
(5,000 ft) a.s.l. and drifted as far away as 37 km NW and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the
Buenos Aires VAAC reported that during 29 July-1 August, and on 4
August, ash plumes from Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-
dome complex rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l.
and drifted N, S, and SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

COLIMA México 19.514°N, 103.62°W; summit elev. 3850 m

The government of the state of Colima reported that during 29 July-4
August white and sometimes gray plumes from Colima rose to altitudes
of 4-4.3 km (13,100-14,100 ft) a.s.l. Some plumes drifted SW and W.

Geologic Summary. The Colima volcanic complex is the most prominent
volcanic center of the western Mexican Volcanic Belt. It consists of
two southward-younging volcanoes, Nevado de Colima (the 4,320 m high
point of the complex) on the N and the historically active Volcán de
Colima on the S. Volcán de Colima (also known as Volcán Fuego) is a
youthful stratovolcano constructed within a 5-km-wide caldera,
breached to the S, that has been the source of large debris
avalanches. Major slope failures have occurred repeatedly from both
the Nevado and Colima cones, and have produced a thick apron of debris-
avalanche deposits on three sides of the complex. Frequent historical
eruptions date back to the 16th century. Occasional major explosive
eruptions (most recently in 1913) have destroyed the summit and left a
deep, steep-sided crater that was slowly refilled and then overtopped
by lava dome growth.

Map

Source: Gobierno del Estado de Colima

Colima Information from the Global Volcanism Program

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

On 31 July, KVERT reported that activity from Ebeko had remained at
low levels since 13 July. The Level of Concern Color Code was lowered
to Green.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Ebeko Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 31 July and 3 August, INSIVUMEH reported that explosions from Fuego
produced ash plumes that rose to altitudes of 4-4.6 km (13,100-15,100
ft) a.s.l. and drifted W. Some explosions were accompanied by rumbling
noises. Incandescent material was ejected 75 m high and avalanches
occurred on the main cone. Fumarolic plumes rose 200 m and drifted W
and NW. The frequency of explosions significantly increased during 2-3
August.

Geologic Summary. Volcán Fuego, one of Central America's most active

volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

On 4 August, INGEOMINAS reported that activity from Galeras had
remained at a low level since the previous report on 28 July; the
Alert Level was lowered to III (Yellow; "changes in the behavior of
volcanic activity"). During the previous few days, active fumaroles
were seen on the W flank of the active cone.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 29 July-4 August, HVO reported that lava flowed SE from

underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless
shield complex through a lava tube system, reaching the Waikupanaha
ocean entry. Thermal anomalies detected in satellite images and visual

observations revealed active surface flows on the pali. The vent in

Halema'uma'u crater continued to produce a diffuse white plume that

drifted mainly SW. Small amounts of ash-sized "rock dust," likely
generated from small wall collapses in the vent, were retrieved from
collection bins placed near the plume. The sulfur dioxide emission
rate at the summit remained elevated; 675 tonnes per day was measured
on 31 July. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that during 29 July-4 August seven pulses of

seismic tremor from Nevado del Huila indicated explosions. Gas plumes

seen on a web camera drifted W. On 3 August, ashfall was reported in
areas to the W. The Alert Level remained at III (Yellow; "changes in

the behavior of volcanic activity").

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Huila Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 31 July and 3 August, INSIVUMEH reported that white and blue plumes
from Pacaya's MacKenney cone drifted S and SW. Multiple lava flows
50-300 m long traveled S and SW.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 22-30 July incandescence from Rabaul
caldera's Tavurvur cone was occasionally visible at night. Steam
plumes rose 1.5 km above the crater. During 28-30 July, ash plumes
also rose 1.5 km above the crater, and rumbling and roaring noises
were reported. On 30 July, incandescent lava fragments were ejected
from the crater. Ashfall was reported in areas to the NW. Based on

analyses of satellite imagery, the Darwin VAAC reported that on 2

August ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. and
drifted 55-90 km SW and S.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Sakura-jima during 31 July-4 August. Plumes rose to altitudes of
2.1-3.4 km (7,000-11,000 ft) a.s.l. on all days except 1 August.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 31 July and 3 August, INSIVUMEH reported that explosions from Santa
María's Santiaguito lava dome complex produced ash plumes and that the
Caliente lava dome was incandescent. On 3 August, ash plumes rose to
an altitude of 3.1 km (10,200 ft) a.s.l. and drifted W. Fumarolic
plumes rose 200 m above Caliente dome. Rumbling noises were
occasionally heard.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 24-31 July seismic activity from Shiveluch
was above background levels. Based on interpretations of seismic data,
ash plumes possibly rose to an altitude of 6.5 km (21,300 ft) a.s.l.
Steam-and-gas plumes with some ash content were also noted. Analyses

of satellite imagery revealed a large daily thermal anomaly over the

lava dome. According to video camera data, ash plumes rose to an
altitude of 5 km (16,400 ft) a.s.l. on 23 and 27 July; gas-and-steam
plumes rose to an altitude of 2.7 km (8,900 ft) a.s.l. on 24 and 27

July. The Level of Concern Color Code remained at Orange.

Based on analyses of satellite imagery and information from KEMSD, the

Tokyo VAAC reported that during 1-2 August eruptions produced plumes
that rose to altitudes of 3-5.8 km (10,000-19,000 ft) a.s.l. and
drifted E and NE.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion
from Suwanose-jima on 5 August. Details of possible resultant ash

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Aug 13, 2009, 10:43:59 PM8/13/09

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SI / USGS Weekly Volcanic Activity Report

5 August-11 August 2009

New Activity/Unrest:
| Ibu, Halmahera
| Mayon, Luzon

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)

| Dukono, Halmahera
| Kilauea, Hawaii (USA)

| Rabaul, New Britain
| Sakura-jima, Kyushu

| Shiveluch, Central Kamchatka (Russia)
| Slamet, Central Java (Indonesia)

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

IBU Halmahera 1.488°N, 127.63°E; summit elev. 1325 m

CVGHM reported that white and gray plumes from Ibu rose 300-400 m
above the crater rim during 15 July-4 August, and that earthquakes
became more frequent during 27 July-4 August. Lava flows were seen on
2 August. Later that day, a thunderous sound was followed by
incandescence at the summit. On 3 August, incandescent material was
ejected as high as 20 m above the crater. On 5 August, the Alert Level
was increased to 3 (on a scale of 1-4). The growing lava dome had
reached a height so that it was visible from Duono Village, about 5 km
NW. Residents and tourists were not permitted within 2 km of the
crater.

Geologic Summary. The truncated summit of Gunung Ibu stratovolcano
along the NW coast of Halmahera Island has large nested summit
craters. The inner crater, 1 km wide and 400 m deep, contained several
small crater lakes through much of historical time. The outer crater,
1.2 km wide, is breached on the north side, creating a steep-walled
valley. A large parasitic cone is located ENE of the summit. A smaller
one to the WSW has fed a lava flow down the western flank. A group of
maars is located below the northern and western flanks of the volcano.
Only a few eruptions have been recorded from Ibu in historical time,
the first a small explosive eruption from the summit crater in 1911.
An eruption producing a lava dome that eventually covered much of the
floor of the inner summit crater began in December 1998.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Ibu Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

According to a news article from 6 August, a volcanologist from
PHIVOLCS reported that the number of earthquakes from Mayon had
decreased, but the volume of sulfur dioxide emissions had increased
sharply during the previous 24 hours. On 4 August, sulfur dioxide was
emitted at a rate of 707 tonnes per day, down from 915 tonnes per day
on 30 July. The rate increased to 1,977 tonnes per day on 5 August.
Authorities declared four villages off-limits to people.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Daily Inquirer

Mayon Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 10 August a diffuse ash plume from Bagana rose to an altitude of 3
km (10,000 ft) a.s.l. and drifted 55 km NW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 4-7 August ash plumes from Batu Tara rose to altitudes of
1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted 45-90 km W, NW, and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 6-7 and 10 August ash plumes from Dukono rose to altitudes of
2.4-3 km (8,000-10,000 ft) a.s.l. and drifted 45-130 km NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 5-11 August, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry.
Thermal anomalies detected in satellite images and visual observations

revealed active surface flows on the pali, and along the E and W TEB
flow field. The vent in Halema'uma'u crater continued to produce a

diffuse white plume that drifted mainly SW. Small amounts of ash-sized

"rock dust," likely generated from small vent wall collapses, were

retrieved from collection bins placed near the plume. The sulfur

dioxide emission rate at the summit remained elevated; 1,800 tonnes
per day was measured on 7 August. The 2003-2007 average rate was 140
tonnes per day. For the first time in weeks, on 10 August,
incandescence from the vent was seen.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 5-11 August ash plumes from Rabaul caldera's Tavurvur cone rose
to altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted 25-185
km in multiple directions.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that eruptions
and explosions from Sakura-jima during 5-10 August produced plumes
that rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. Pilots
reported that ash plumes rose to altitudes of 1.8-4 km (6,000-13,000
ft) a.s.l. during 7 and 9-10 August. Plumes drifted in multiple
directions.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 31 July-7 August seismic activity from
Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on

interpretations of seismic data, ash plumes possibly rose to an

altitude of 7.5 km (24,600 ft) a.s.l. Steam-and-gas plumes with some
ash content were also noted. According to video camera data, ash
plumes rose to an altitude of 4 km (13,100 ft) a.s.l. on 2 August; gas-
and-steam plumes rose to an altitude of 3.5 km (11,500 ft) a.s.l. on 2
and 4 August. The Level of Concern Color Code remained at Orange.

Based on analyses of satellite imagery and information from KEMSD, the

Tokyo VAAC reported that on 6 and 9 August eruptions produced plumes
that rose to altitudes of 4.6-5.2 km (15,000-17,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SLAMET Central Java (Indonesia) 7.242°S, 109.208°E; summit elev. 3428
m

Based on a pilot observation, the Darwin VAAC reported that on 8
August an ash plume from Slamet rose 90 m above the summit. Ash was
not detected in satellite imagery.

Geologic Summary. Slamet, Java's second highest volcano at 3428 m and
one of its most active, has a cluster of about three dozen cinder
cones on its lower SE-NE flanks and a single cinder cone on the
western flank. Slamet is composed of two overlapping edifices, an
older basaltic-andesite to andesitic volcano on the west and a younger
basaltic to basaltic-andesite one on the east. Gunung Malang II cinder
cone on the upper eastern flank on the younger edifice fed a lava flow
that extends 6 km to the east. Four craters occur at the summit of
Gunung Slamet, with activity migrating to the SW over time. Historical
eruptions, recorded since the 18th century, have originated from a 150-
m-deep, 450-m-wide, steep-walled crater at the western part of the
summit and have consisted of explosive eruptions generally lasting a
few days to a few weeks.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Slamet Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion

from Suwanose-jima on 10 August. Details of a possible resultant ash
plume were not reported.

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SI / USGS Weekly Volcanic Activity Report

12 August-18 August 2009

New Activity/Unrest:

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile

| Dukono, Halmahera
| Kilauea, Hawaii (USA)

| Popocatépetl, México

| Rabaul, New Britain
| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)
| Ubinas, Perú

This page is updated on Wednesdays,
please see the GVP Home Page for news
of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

Based on analyses of satellite imagery and information from KEMSD, the

Tokyo VAAC reported that on 17 August an eruption from Kliuchevskoi
produced a plume that rose to an altitude of 5.2 km (17,000 ft) a.s.l.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

KORYAKSKY Eastern Kamchatka 53.320°N, 158.688°E; summit elev. 3456 m

KVERT reported that during 10-12 August seismic activity from
Koryaksky was above background levels. On 12 August, an ash plume seen
on satellite imagery drifted 180 km ESE at an altitude of 3.5 km
(11,500 ft) a.s.l. During 15-16 August seismic activity increased, and
seismic tremor was detected. On 16 August, a gas plume with a small
amount of ash was seen on satellite imagery drifting 80 km WNW. During
17-18 August, an ash plume rose to an altitude of 4 km (13,100 ft)
a.s.l. Ashfall up to 1 mm thick was reported in areas to the SW. The
Level of Concern Color Code was raised to Orange.

Geologic Summary. The large symmetrical Koryaksky stratovolcano is the
most prominent landmark of the NW-trending Avachinskaya volcano group,
which towers above Kamchatka's largest city, Petropavlovsk. Erosion
has produced a ribbed surface on the eastern flanks of the 3456-m-high
volcano; the youngest lava flows are found on the upper western flank
and below SE-flank cinder cones. No strong explosive eruptions have
been documented during the Holocene. Extensive Holocene lava fields on
the western flank were primarily fed by summit vents; those on the SW
flank originated from flank vents. Lahars associated with a period of
lava effusion from south- and SW-flank fissure vents about 3900-3500
years ago reached Avacha Bay. Only a few moderate explosive eruptions
have occurred during historical time. Koryaksky's first historical

eruption, in 1895, also produced a lava flow.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Koryaksky Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 14 August a 2-hour-long thermal anomaly detected over Pagan
was followed by a small emission. The emission, hotter than its
surroundings, drifted NW and quickly dissipated.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Pagan Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The IG reported that seismic tremor from Reventador was sporadically
detected during 21 July-3 August. On 4 August, seismicity increased
and periods of tremor frequently saturated the seismic stations.
Thermal anomalies detected in satellite imagery on 1 and 2 August
became more intense on 4, 5, and 10 August. On 6 August, a steam plume
rose 1.2 km above the crater and drifted W. Incandescent blocks were
ejected from the crater and fell onto the flanks. Thermal images taken
from a location 7 km E of Reventador revealed a linear area of higher
temperatures, confirming the presence of a new lava flow on the S
flank. Incandescence in the crater was seen during observations on 9
August. According to the Washington VAAC, IG reported that an ash
plume rose to an altitude of 3.6 km (11,700 ft) a.s.l. and drifted NW
on 15 August.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),
Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

TALANG Sumatra (Indonesia) 0.978°S, 100.679°E; summit elev. 2597 m

On 17 August, CVGHM raised the Alert Level for Talang from 2 to 3 (on
a scale of 1-4) because of increased seismicity during the previous
two days. Foggy conditions prevented visual observations. Visitors and
tourists were advised not to go within a 3-km radius of the summit.

Geologic Summary. Talang, which forms a twin volcano with the extinct
Pasar Arbaa volcano, has two crater lakes on its flanks. The largest
of these is 1 x 2 km wide Danau Talang. No historical eruptions have
occurred from the summit of the volcano, which lacks a crater. All
historical eruptions from Gunung Talang volcano have involved small-to-
moderate 19th-century explosive activity originating from a series of
small craters in a valley on the upper NE flank.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Talang Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 12-13 and 15-17 August ash plumes from Batu Tara rose to
altitudes of 1.5-3 m (5,000-7,000 ft) a.s.l. and drifted 5-110 km W,
NW, and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the

Buenos Aires VAAC reported that on 13 and 18 August ash plumes from
Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex rose to
altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 15 August an ash plume from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted more than 90 km NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 12-18 August, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry.
Thermal anomalies detected in satellite images and visual observations

revealed active surface flows on the flow field.

The vent in Halema'uma'u crater continued to produce a diffuse white
plume that drifted mainly SW. Small amounts of ash-sized "rock dust,"

were retrieved from collection bins placed near the plume; possibly
fresh tephra, including Pele's Hair, was collected on 12 August.
Rushing gas sounds were often heard in the vicinity of the vent.
During 12-13 August, a new, brightly incandescent hole appeared on the
floor of the vent. The vent increased in size and incandescence
continued to be seen on the web camera during the reporting period.

The sulfur dioxide emission rate at the summit remained elevated;

2,050 and 900 tonnes per day was measured on 12 and 14 August;
respectively. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 10 and 12-17 August emissions of steam

and gas from Popocatépetl sometimes contained slight amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 14 August ash plumes from Rabaul caldera's Tavurvur cone rose to an
altitude of 3 km (10,000 ft) a.s.l. and drifted 25-165-280 km NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported eruptions and
explosions from Sakura-jima during 12-17 August. Plumes rose to
altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. during 14-17 August
and occasionally drifted E or N.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 7-17 August seismic activity from Shiveluch

was above background levels. Analyses of satellite imagery revealed a
large daily thermal anomaly over the lava dome. Based on
interpretations of seismic data, ash plumes possibly rose to an

altitude of 5 km (16,400 ft) a.s.l. The Level of Concern Color Code
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Suwanose-jima during 16-17 August produced plumes that rose to an
altitude of 1.8 km (6,000 ft) a.s.l. Plumes drifted E on 16 August.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

Based on a SIGMET notice, the Buenos Aires VAAC reported that an
emission from Ubinas was seen on 15 August. Ash was not detected in
satellite imagery.

Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of

Ubinas, Peru's most active volcano, gives it a truncated appearance.
Ubinas is the northernmost of three young volcanoes located along a
regional structural lineament about 50 km behind the main volcanic
front of Peru. The upper slopes of the stratovolcano, composed
primarily of Pleistocene andesitic lava flows, steepen to nearly 45
degrees. The steep-walled, 150-m-deep summit caldera contains an ash
cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-
avalanche deposits from the collapse of the SE flank of Ubinas extend
10 km from the volcano. Widespread Plinian pumice-fall deposits from
Ubinas include some of Holocene age. Holocene lava flows are visible
on the volcano's flanks, but historical activity, documented since the
16th century, has consisted of intermittent minor explosive eruptions.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Ubinas Information from the Global Volcanism Program

Bert Hyman

unread,

Aug 20, 2009, 1:10:08 PM8/20/09

to

In news:d216f395-7312-4156...@o6g2000yqj.googlegroups.com
Last Post <last...@primus.ca> wrote:

> SI / USGS Weekly Volcanic Activity Report

All very interesting to someone I suppose, but a few questions:

1. Why's this posted to talk.politics.misc? Do you think volcanoes are part
of a political plot?

2. Why's this posted to sci.skeptic? Do you think some people don't believe
in volcanoes?

3. If you must post, why not just post the link to the original article?

--
Bert Hyman St. Paul, MN be...@iphouse.com

Leonard

unread,

Aug 20, 2009, 2:35:11 PM8/20/09

to

On 8/20/09 1:10 PM, in article Xns9C6D7B82DC9...@216.250.184.7,
"Bert Hyman" <be...@iphouse.com> wrote:

> In news:d216f395-7312-4156...@o6g2000yqj.googlegroups.com
> Last Post <last...@primus.ca> wrote:
>
>> SI / USGS Weekly Volcanic Activity Report
>
> All very interesting to someone I suppose, but a few questions:
>
> 1. Why's this posted to talk.politics.misc? Do you think volcanoes are part
> of a political plot?

�� Dear Bert: you appear to be losing it. Are you
unaware that climate change has, by AlGore and
a bunch of UN fascists, been turned into the
greatest scam in history. It is much akin to
what the mediaeval popes did to Galileo

�� The major factors in our changing climate, are
the Sun and the many volcanoes including the
many tectonic seeps and undersea volcanoes.
Eventually some people like you might become
aware that the anthroogenic global warming
alarmist whores are just that, devoid of science
but full of propaganda BS

>
> 2. Why's this posted to sci.skeptic? Do you think some people don't believe
> in volcanoes?

�� ROTFLMAO!! I did not think of that.
In real science the burden of proof is always on
the proposer, never on the sceptics. The alarmists
hos have labelled us "denialists" to tie us in
with Holocaust deniers, and to deny our science.

> 3. If you must post, why not just post the link to the original article?

The Smithsonian posts this every Wednesday. If
I post a link, those who should read it won't
and neither will the lurkers.

Leonard

unread,

Aug 20, 2009, 7:18:05 PM8/20/09

to

From: "leonard7...
<http://groups.google.ca/groups/unlock?_done=/group/sci.environment/browse_f
rm/thread/cf191a65ebddbf03%3Fscoring%3Dd%26&msg=1521bcf8660d5bd9>
@gmail.com" <leonard7...
<http://groups.google.ca/groups/unlock?_done=/group/sci.environment/browse_f
rm/thread/cf191a65ebddbf03%3Fscoring%3Dd%26&msg=1521bcf8660d5bd9>
@gmail.com>

Date: Wed, 3 Jun 2009 22:51:12 -0700 (PDT)

Local: Thurs, Jun 4 2009 1:51�am

Three New Volcanos Erupting This Week~~ 19 Total Active

New Activity/Unrest:

| Karangetang [Api Siau], Siau I

| Makian, Halmahera
| Slamet, Central Java (Indonesia)

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)

| Chait�n, Southern Chile
| Dukono, Halmahera
| Etna, Sicily (Italy)

| Kilauea, Hawaii (USA)
| Llaima, Central Chile

| Nevado del Huila, Colombia
| Popocat�petl, M�xico

| Rabaul, New Britain
| Redoubt, Southwestern Alaska

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

| Soufri�re Hills, Montserrat
| Tungurahua, Ecuador
| Ubinas, Per�

This page is updated on Wednesdays, please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KARANGETANG [API SIAU] Siau I 2.78�N, 125.40�E; summit elev. 1784 m

CVGHM reported that seismicity from Karangetang increased during 30-31
May and tremor was detected. On 30 May, diffuse white plumes rose
10-50 m high and incandescence was seen at the crater. On 31 May,
white emissions from Utama Crater in the N part of the summit region
rose 100 m. Incandescent material traveled as far as 2.3 km, mostly
down the S flank. Ash plumes that rose 25-700 m were accompanied by
thunderous sounds. The Alert Level was raised to 4, the highest level
on a scale of 1-4. People were advised not to go within a 3-km-radius
of the active area. According to a news article, over 350 people
evacuated the area.

Geologic Summary. Karangetang (also known as Api Siau) lies at the

northern end of the island of Siau, N of Sulawesi, and contains five

summit craters strung along a N-S line. One of Indonesia's most active

volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Sources: Center of Volcanology and Geological Hazard Mitigation
(CVGHM), Xinhua

Karangetang [Api Siau] Information from the Global Volcanism Program

MAKIAN Halmahera 0.32�N, 127.40�E; summit elev. 1357 m

CVGHM reported that during 28 May-2 June seismicity from Makian
increased, particularly the occurrence of tremor. Little, if any,

increases in emissions were seen. The Alert level was raised to 2 (on
a scale of 1-4).

Geologic Summary. Makian volcano forms a 10-km-wide island near the
southern end of a chain of volcanic islands off the W coast of
Halmahera and has been the source of infrequent, but violent eruptions
that have devastated villages on the island. The large 1.5-km-wide
summit crater, containing a small lake on the NE side, gives the peak
a flat-topped profile. Two prominent valleys extend to the coast from
the summit crater on the N and E sides. Four parasitic cones are found
on the western flanks. Eruption have been recorded since about 1550;
major eruptions in 1646, 1760-61, 1861-62, 1890, and 1988 caused
extensive damage and many fatalities.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Makian Information from the Global Volcanism Program

SLAMET Central Java (Indonesia) 7.242�S, 109.208�E; summit elev. 3428
m

Based on ground information from CVGHM, the Darwin VAAC reported that
on 27 May an ash plume from Slamet rose to an altitude of 4.3 km
(14,000 ft) a.s.l. Analysis of satellite imagery indicated that a
possible plume rose to an altitude of 6.1 km (20,000 ft) a.s.l., but
ash was not conclusively detected.

Geologic Summary. Slamet, Java's second highest volcano at 3428 m and
one of its most active, has a cluster of about three dozen cinder
cones on its lower SE-NE flanks and a single cinder cone on the
western flank. Slamet is composed of two overlapping edifices, an
older basaltic-andesite to andesitic volcano on the west and a younger
basaltic to basaltic-andesite one on the east. Gunung Malang II cinder
cone on the upper eastern flank on the younger edifice fed a lava flow
that extends 6 km to the east. Four craters occur at the summit of
Gunung Slamet, with activity migrating to the SW over time. Historical
eruptions, recorded since the 18th century, have originated from a 150-
m-deep, 450-m-wide, steep-walled crater at the western part of the
summit and have consisted of explosive eruptions generally lasting a
few days to a few weeks.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Slamet Information from the Global Volcanism Program

Rob Dekker

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Aug 26, 2009, 6:32:47 AM8/26/09

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And this vulcano report is relevant in sci.energy, because ?

Rob

Last Post

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Aug 26, 2009, 11:09:28 PM8/26/09

to

SI / USGS Weekly Volcanic Activity Report

19 August-25 August 2009

New Activity/Unrest:
| Koryaksky, Eastern Kamchatka

Ongoing Activity:

| Bagana, Bougainville
| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile
| Fuego, Guatemala

| Kilauea, Hawaii (USA)
| Popocatépetl, México

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

| Tungurahua, Ecuador | Ubinas, Perú

This page is updated on Wednesdays,
please see the GVP Home Page for news
of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between

the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KORYAKSKY Eastern Kamchatka 53.320°N, 158.688°E; summit elev. 3456 m

KVERT reported that during 14-21 August seismic activity from
Koryaksky was slightly above background levels. During 13-16 August,
gas-and-steam plumes rose to altitudes of 3.5-5 km (11,500-16,400 ft)
a.s.l. Based on visual observations during 16-20 August, gas-and-steam
plumes containing ash rose to altitudes of 3.5-4.2 km (11,500-13,800
ft) a.s.l. and drifted in multiple directions. Ash plumes were also
seen in satellite imagery, drifting 215 km E and W. On 23 August, a
probable ash plume detected in satellite imagery drifted 50 km ESE.
During 24-25 August, seismicity increased; more than 100 earthquakes
were recorded. The Level of Concern Color Code remained at Orange.

Geologic Summary. The large symmetrical Koryaksky stratovolcano is the
most prominent landmark of the NW-trending Avachinskaya volcano group,
which towers above Kamchatka's largest city, Petropavlovsk. Erosion
has produced a ribbed surface on the eastern flanks of the 3456-m-high
volcano; the youngest lava flows are found on the upper western flank
and below SE-flank cinder cones. No strong explosive eruptions have
been documented during the Holocene. Extensive Holocene lava fields on
the western flank were primarily fed by summit vents; those on the SW
flank originated from flank vents. Lahars associated with a period of
lava effusion from south- and SW-flank fissure vents about 3900-3500
years ago reached Avacha Bay. Only a few moderate explosive eruptions
have occurred during historical time. Koryaksky's first historical
eruption, in 1895, also produced a lava flow.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Koryaksky Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 19 August an ash plume from Bagana rose to an altitude of 2.1 km
(7,000 ft) a.s.l. and drifted more than 90 km W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 19 and 21-25 August ash plumes from Batu Tara rose to an
altitude of 1.5 m (5,000 ft) a.s.l. and drifted 35-150 km W, WNW, and
NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the

Buenos Aires VAAC reported that on 19 and 23 August steam-and-ash

plumes from Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex

were detected. On 19 August, the plume drifted SW.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

Based on information from the Tegucigalpa MWO, the Washington VAAC
reported that ash was detected within 15 km of Fuego on 19 August. Ash
was not identified in satellite imagery. On 21 and 25 August,
INSIVUMEH reported that explosions produced plumes that rose to
altitudes of 4.2-4.6 km (13,800-15,100 ft) a.s.l. and drifted 5-7 km W
and SW. On 21 August rumbling sounds were accompanied by incandescent
tephra ejected 75 m high. On 25 August, ashfall was reported in areas
to the SW.

Geologic Summary. Volcán Fuego, one of Central America's most active

volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 19-25 August, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry.
Thermal anomalies detected in satellite images and visual observations

during 18-19 August revealed active surface lava flows. The vent in

Halema'uma'u crater continued to produce a diffuse white plume that

drifted mainly SW. Small amounts of ash-sized "rock dust" were
retrieved from collection bins placed near the plume. Rushing gas
sounds were occasionally heard in the vicinity of the vent.
Incandescence from the floor of the vent was visible at night on the
web camera. The sulfur dioxide emission rate at the summit remained
elevated; 950-1,140 tonnes per day was measured during 19-21 August.

The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

Based on information from the Mexico City MWO and analyses of
satellite imagery, the Washington VAAC reported that on 20 August an
ash plume from Popocatépetl rose to an altitude of 8.2 km (27,000 ft)
a.s.l. and drifted 13 km W. An ash plume that drifted more than 35 km
NNE was seen in satellite imagery on 25 August. CENAPRED reported that
during 20-25 August emissions of steam and gas contained slight
amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Sources: Centro Nacional de Prevencion de Desastres (CENAPRED),

Washington Volcanic Ash Advisory Center (VAAC)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Sakura-jima during 19-25 August produced plumes that rose to
altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. Plumes occasionally
drifted N, E, and SE. A pilot reported that on 24 August an ash plume
rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted less than
20 km S.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 14-24 August seismic activity from

Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on

interpretations of seismic data, ash plumes possibly rose to an
altitude of 5.9 km (19,400 ft) a.s.l. and hot avalanches occurred at
the lava dome. An ash plume drifted 50 km S on 14 August, and gas-and-
steam plumes rose to an altitude of 4 km (13,100 ft) a.s.l. on 16
August. The Level of Concern Color Code remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that inclement weather often prevented observations of

Tungurahua during 19-25 August, although steam-and-gas emissions were
observed rising from the crater during 23-24 August. On 19 August,
lahars that descended W drainages carried blocks up to 30 cm in
diameter. Lahars also descended W and N drainages on 21 August.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of

Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

Based on a pilot observation, the Buenos Aires VAAC reported that an
emission from Ubinas was seen on 23 August. Ash was not detected in

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SI / USGS Weekly Volcanic Activity Report

26 August-1 September 2009

New Activity/Unrest:
| Kanlaon, Negros I
Kolokol Group, Urup Island
| Koryaksky, Eastern Kamchatka

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)

| Kizimen, Eastern Kamchatka
| Pacaya, Guatemala

| Popocatépetl, México
| Rabaul, New Britain
| Sakura-jima, Kyushu

| Santa María, Guatemala

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see

the GVP Home Page for news of the latest
significant activity.

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the

Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KANLAON Negros I 10.412°N, 123.132°E; summit elev. 2435 m

PHIVOLCS reported that during 23 August-1 September the seismic
network for Kanlaon detected a significant rise in the number of
earthquakes. A few of the earthquakes were felt as far away as Bago
City, 30 km NW. The epicenters clustered on the NW flank.

Geologic Summary. Kanlaon volcano (also spelled Canlaon), the most
active of the central Philippines, forms the highest point on the
island of Negros, about 500 km ESE of Manila. The massive
stratovolcano is dotted with fissure-controlled pyroclastic cones and
craters, many of which are filled by lakes. The summit of Kanlaon
contains a broad northern crater with a crater lake and a smaller, but
higher, historically active crater to the south. Historical eruptions,
recorded since 1866, have typically consisted of phreatic explosions
of small-to-moderate size that produce minor ashfalls near the
volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Kanlaon Information from the Global Volcanism Program

KOLOKOL GROUP Urup Island 46.042°N, 150.05°E; summit elev. 1328 m

Based on analyses of satellite imagery, SVERT reported that on 26
August a gas-and-steam plume possibly containing ash rose from Berg
(part of the Kolokol Group of volcanoes) to an altitude greater than 6
km (19,700 ft) a.s.l. and drifted NE.

Geologic Summary. A group of Holocene volcanoes in central Urup Island
is named after its most prominent volcano, Kolokol. Berg and Trezubetz
volcanoes, flanking Kolokol on the NW, have breached summit calderas
partially filled by lava domes. Trezubetz, whose name means "trident,"
has an eroded crater rim with three large peaks when seen at sea from
the north. Kolokol volcano rises to 1328 m and is sometimes known as
Urup-Fuji because of its symmetrical profile. The crater of Kolokol is
not well preserved, but the volcano displays no evidence of glacial
erosion. Several lava flows originate from Kolokol; one of these
extends almost to the Sea of Okhotsk coast. A viscous lava flow
armoring the SE flank is probably the most recent from Kolokol. Borzov
volcano, the oldest of the group, lies to the SW of Kolokol. Eruptions
of the Kolokol volcano group have been observed in historical time
since the late-18th century. Berg volcano has been most active, but
Trezubetz erupted in 1924.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Kolokol Group Information from the Global Volcanism Program

KORYAKSKY Eastern Kamchatka 53.320°N, 158.688°E; summit elev. 3456 m

KVERT reported that seismic activity from Koryaksky was slightly above
background levels during 20-23 August and at background levels during
24-27 August. Ash plumes were seen in satellite imagery drifting more
than 385 km in easterly directions. Gas-and-steam plumes containing
ash that rose to an altitude of 3.7 km (12,100 ft) a.s.l. were seen
drifting in multiple directions during 26-27 August. The Level of

Concern Color Code remained at Orange.

Geologic Summary. The large symmetrical Koryaksky stratovolcano is the

most prominent landmark of the NW-trending Avachinskaya volcano group,
which towers above Kamchatka's largest city, Petropavlovsk. Erosion
has produced a ribbed surface on the eastern flanks of the 3456-m-high
volcano; the youngest lava flows are found on the upper western flank
and below SE-flank cinder cones. No strong explosive eruptions have
been documented during the Holocene. Extensive Holocene lava fields on
the western flank were primarily fed by summit vents; those on the SW
flank originated from flank vents. Lahars associated with a period of
lava effusion from south- and SW-flank fissure vents about 3900-3500
years ago reached Avacha Bay. Only a few moderate explosive eruptions
have occurred during historical time. Koryaksky's first historical
eruption, in 1895, also produced a lava flow.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Koryaksky Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 26 August-1 September ash plumes from Batu Tara rose to
altitudes of 1.5-2.4 m (5,000-8,000 ft) a.s.l. and drifted 15-55 km W,
NW, and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores

Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 4-20 August Chaitén's Domo Nuevo 1
and Domo Nuevo 2 lava-dome complex continued to grow, particularly in
the W area of the complex. Gas-and-ash plumes occasionally rose 1.5 km
above the lava domes. Based on web camera views and analyses of
satellite imagery, the Buenos Aires VAAC reported that on 31 August a
4-km-wide ash plume drifted 20 km NE at an altitude of 2.1 km (7,000
ft) a.s.l.

Geologic Summary. Chaitén is a small, glacier-free caldera with a

Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery and pilot observations, the
Darwin VAAC reported that during 26 August-1 September ash plumes from
Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted
20-65 km NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was slightly above
background levels on 20 and 21 August and at background levels during
22-31 August. Analysis of satellite imagery revealed a small thermal
anomaly over the volcano on 21 August. The Level of Concern Color Code
was lowered to Green on 31 August.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 26 August-1 September, HVO reported that lava flowed SE from

underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless
shield complex through a lava tube system, reaching the Waikupanaha

ocean entry. The vent in Halema'uma'u crater continued to produce a

diffuse white plume that drifted mainly SW. Small amounts of ash-sized
"rock dust" were retrieved from collection bins placed near the plume.

Degassing sounds were occasionally heard in the vicinity of the vent.

Incandescence from the floor of the vent was visible at night on the

web camera, or from HVO. The sulfur dioxide emission rate at the
summit remained elevated; 1,000 and 950 tonnes per day were measured
on 26 and 27 August, respectively. The 2003-2007 average rate was 140
tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KIZIMEN Eastern Kamchatka 55.130°N, 160.32°E; summit elev. 2376 m

KVERT reported that seismic activity at Kizimen had decreased to
background levels on 23 August and remained there through 31 August.
Volcanologists observed gas-and-steam plumes rising from the summit,
activity described as normal. The Level of Concern Color Code was
lowered to Green on 31 August.

Geologic Summary. Kizimen is an isolated, conical stratovolcano that
is morphologically similar to Mount St. Helens prior to its 1980
eruption. The summit of Kizimen consists of overlapping lava domes,
and blocky lava flows descend the flanks of the volcano, which is the
westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-
m-high Kizimen was formed during four eruptive cycles beginning about
12,000 years ago and lasting 2,000-3,500 years. The largest eruptions
took place about 10,000 and 8300-8400 years ago, and three periods of
longterm lava-dome growth have occurred. The latest eruptive cycle
began about 3,000 years ago with a large explosion and was followed by
lava-dome growth lasting intermittently about 1,000 years. An
explosive eruption about 1,100 years ago produced a lateral blast and
created a 1.0 x 0.7 km wide crater breached to the NE, inside which a
small lava dome (the fourth at Kizimen) has grown. A single explosive
eruption, during 1927-28, has been recorded in historical time.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kizimen Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 28 August and 1 September, INSIVUMEH reported that white and blue

plumes from Pacaya's MacKenney cone drifted S and SW. Multiple lava

flows 15-200 m long traveled S and SW.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 26-27 August emissions of steam and gas
from Popocatépetl sometimes contained slight amounts of ash. Based on
information from the Mexico City MWO, the Washington VAAC reported
that on 27 August an ash plume rose to an altitude of 6.1 km (20,000

ft) a.s.l. and drifted SW.

Geologic Summary. Popocatépetl, whose name is the Aztec word for

smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Sources: Centro Nacional de Prevencion de Desastres (CENAPRED),
Washington Volcanic Ash Advisory Center (VAAC)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 28-29 August ash plumes from Rabaul caldera's Tavurvur cone
rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 90-260 km
NW and W.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 26-29 August and 1 September produced plumes
that rose to altitudes of 1.2-3.4 km (4,000-11,000 ft) a.s.l. Plumes
occasionally drifted N, NE, and E. An explosion was reported on 31
August but no information about a possible resulting plume was
reported.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 28 August, INSIVUMEH reported an explosion from Santa María's
Santiaguito lava dome complex. On 1 September, fumarolic plumes rose
150 m above Caliente dome and drifted SW. Avalanches descended the SW
flank of the dome.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 21-27 August seismic activity from

Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on
interpretations of seismic data, ash plumes possibly rose to an

altitude of 4.8 km (15,700 ft) a.s.l. and hot avalanches occurred on
the lava dome. Gas-and-steam plumes rose to an altitude of 3.3 km
(10,800 ft) a.s.l. during 20-23 and 26-27 August. The Level of Concern

Color Code remained at Orange.

Based on information from KEMSD, the Tokyo VAAC reported that on 31
August eruptions produced plumes that rose to altitudes of 4.6-5.5 km
(15,000-18,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Suwanose-jima during 27-29 August sometimes produced plumes that
rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted W.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

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SI / USGS Weekly Volcanic Activity Report

Sally Kuhn Sennert - Weekly Report Editor
URL:http://www.volcano.si.edu/reports/usgs
2 September - 8 September 2009

New Activity/Unrest:

| Koryaksky, Eastern Kamchatka
| San Cristóbal, Nicaragua

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Kilauea, Hawaii (USA)

| Popocatépetl, México
| Rabaul, New Britain
| Sakura-jima, Kyushu

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays,
please see the GVP Home Page for news
of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between

the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KORYAKSKY Eastern Kamchatka 53.320°N, 158.688°E; summit elev. 3456 m

KVERT reported that activity from Koryaksky decreased on 27 August and
remained low through 4 September. Gas-and-steam plumes rose to an
altitude of 3.7 km (12,100 ft) a.s.l. and drifted in multiple
directions. Tremor was detected by the seismic network during 27-28
August and 1 September. The Level of Concern Color Code was lowered to
Yellow.

Geologic Summary. The large symmetrical Koryaksky stratovolcano is the
most prominent landmark of the NW-trending Avachinskaya volcano group,
which towers above Kamchatka's largest city, Petropavlovsk. Erosion
has produced a ribbed surface on the eastern flanks of the 3456-m-high
volcano; the youngest lava flows are found on the upper western flank
and below SE-flank cinder cones. No strong explosive eruptions have
been documented during the Holocene. Extensive Holocene lava fields on
the western flank were primarily fed by summit vents; those on the SW
flank originated from flank vents. Lahars associated with a period of
lava effusion from south- and SW-flank fissure vents about 3900-3500
years ago reached Avacha Bay. Only a few moderate explosive eruptions
have occurred during historical time. Koryaksky's first historical
eruption, in 1895, also produced a lava flow.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Koryaksky Information from the Global Volcanism Program

SAN CRISTOBAL Nicaragua 12.702°N, 87.004°W; summit elev. 1745 m

Based on analysis of satellite imagery and information from the
Tegucigalpa MWO, the Washington VAAC reported that on 6 September an
explosion from San Cristóbal produced an ash plume that rose to an
altitude no higher than 8.5 km (28,000 ft) a.s.l. The plume drifted 75
km W. According to a news article, ashfall was reported in nearby
towns.

Geologic Summary. The San Cristóbal volcanic complex, consisting of
five principal volcanic edifices, forms the NW end of the Marrabios
Range. The symmetrical 1,745-m-high youngest cone, San Cristóbal
itself (also known as El Viejo), is Nicaragua's highest volcano and is
capped by a 500 x 600 m wide crater. El Chonco, with several flank
lava domes, is located 4 km to the west of San Cristóbal; it and the
eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of
Pleistocene age. Volcán Casita contains an elongated summit crater and
lies immediately E of San Cristóbal; Casita was the site of a
catastrophic landslide and lahar in 1998. The Plio-Pleistocene La
Pelona caldera is located at the eastern end of the San Cristóbal
complex. Historical eruptions from San Cristóbal, consisting of small-
to-moderate explosive activity, have been reported since the 16th
century. Some other 16th-century eruptions attributed to Casita
volcano are uncertain and may pertain to other Marrabios Range
volcanoes.

Map

Sources: Washington Volcanic Ash Advisory Center (VAAC), Associated
Press

San Cristóbal Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 2-8 September ash plumes from Batu Tara rose to an altitude of
1.5 m (5,000 ft) a.s.l. and drifted 10-55 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 20-31 August Chaitén's Domo Nuevo 1

and Domo Nuevo 2 lava-dome complex continued to grow, particularly in

the W area of the complex. Collapses originating from unstable slopes
generated block-and-ash flows, and gas-and-ash plumes occasionally
rose 1.5 km above the lava domes. The Alert Level remained at Red.

Based on web camera views and analyses of satellite imagery, the

Buenos Aires VAAC reported that on 6 September an ash plume rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted E. The next day, a
plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 7-8 September ash plumes from Dukono rose to an altitude of 2.1
km (7,000 ft) a.s.l. and drifted 35-75 km E and SE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 2-8 September, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry.

Thermal anomalies detected in satellite images and visual observations

revealed active surface lava flows in the abandoned Royal Gardens
subdivision.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted mainly SW. Small amounts of ash-sized tephra were
retrieved from collection bins placed near the plume. Degassing and
rockfall sounds were occasionally heard in the vicinity of the vent.
Incandescence from small openings in the floor of the vent, about 200
m below the Halema'uma'u crater floor, was visible at night. The
sulfur dioxide emission rate at the summit remained elevated; 1,200
and 785 tonnes per day were measured on 2 and 3 September,

respectively. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 2-3 September emissions of steam and gas
from Popocatépetl contained slight amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 28 August-3 September white and gray ash
plumes from Rabaul caldera's Tavurvur cone rose 1.5 km above the

crater and produced ashfall in Rabaul town (3-5 km NW) and surrounding

areas. Occasionally, incandescence from the summit crater was seen at
night, and incandescent lava fragments were ejected from the crater.
Rumbling and roaring noises were reported. Based on analyses of
satellite imagery, the Darwin VAAC reported that on 5 and 8 September
ash plumes rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and
drifted 55-90 km N and NE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 2-8 September produced plumes that rose to
altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l. and drifted W, SW, and
S.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 28 August-4 September seismic activity from

Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on
interpretations of seismic data, ash plumes possibly rose to an

altitude of 5.2 km (17,100 ft) a.s.l. and hot avalanches occurred at
the lava dome. Gas-and-steam plumes rose to an altitude of 3 km (9,800
ft) a.s.l. during 28-29 and 31 August, and1-3 September. The Level of

Concern Color Code remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 3-7 September. Details of possible resulting ash
plumes were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-

jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

leona...@gmail.com

unread,

Sep 16, 2009, 5:07:21 PM9/16/09

to

SI / USGS Weekly VolcanicActivityReport

Sally Kuhn Sennert - Weekly Report Editor
URL:http://www.volcano.si.edu/reports/usgs

9 September - 15 September 2009

New Activity/Unrest:

| Langila, New Britain
| Mayon, Luzon
| Shiveluch, Central Kamchatka (Russia)

Ongoing Activity:

| Bagana, Bougainville
| Barren Island, Andaman Is

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Fuego, Guatemala
| Kilauea, Hawaii (USA)

| Pacaya, Guatemala

| Popocatépetl, México
| Rabaul, New Britain
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Slamet, Central Java (Indonesia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays,
please see the GVP Home Page for news
of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

LANGILA New Britain 5.525°S, 148.42°E; summit elev. 1330 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 12 September an ash plume from Langila rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 35 km W.

Geologic Summary. Langila, one of the most active volcanoes of New
Britain, consists of a group of four small overlapping composite cones
on the lower eastern flank of the extinct Talawe volcano. Talawe is
the highest volcano in the Cape Gloucester area of NW New Britain. A
rectangular, 2.5-km-long crater is breached widely to the SE; Langila
volcano was constructed NE of the breached crater of Talawe. An
extensive lava field reaches the coast on the N and NE sides of
Langila. Frequent mild-to-moderate explosive eruptions, sometimes
accompanied by lava flows, have been recorded since the 19th century
from three active craters at the summit of Langila. The youngest and
smallest crater (no. 3 crater) was formed in 1960 and has a diameter
of 150 m.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Langila Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

PHIVOLCS reported that 11 earthquakes from Mayon were detected during
14-15 September. Steam plumes drifted NW and ENE and the sulfur
dioxide gas output decreased. Faint incandescence was observed at
night. On 15 September, three ash explosions produced a brownish plume
that rose no more than 700 m above the crater and drifted SW. The
Alert Level remained at 2 (on a scale of 0-5). The 7-km Extended

Danger Zone (EDZ) on the SE flank and the 6-km Permanent Danger Zone
(PDZ) in all other areas remained in effect.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises

to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of

people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Mayon Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 4-11 September seismic activity from

Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on
interpretations of seismic data, ash plumes possibly rose to an

altitude of 4.2 km (13,800 ft) a.s.l. and hot avalanches occurred at
the lava dome. Gas-and-steam plumes rose to an altitude of 4 km
(13,100 ft) a.s.l. during 4-9 September. An ash plume was seen in
satellite imagery drifting 80 km E on 8 September.

On 11 September, KVERT reported strong explosions. Based on
interpretations of seismic data, ash plumes rose to an altitude
greater than 15 km (49,200 ft) a.s.l. The seismic network then
detected eight minutes of pyroclastic flows from the lava dome;
resulting plumes rose to an altitude of approximately 10 km (32,800
ft) a.s.l. The Level of Concern Color Code was raised to Red. Ten more
events characterized as ash explosions and either pyroclastic flows or
avalanches were detected. Cloud cover prevented visual observations.
Seismicity decreased during 11-12 September, and indicated that ash
plumes rose to altitudes of 4.5-6.5 km (14,800-21,300 ft) a.s.l. The
Level of Concern Color Code was lowered to Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 12-13 September ash plumes from Bagana rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 35-65 km NW and W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BARREN ISLAND Andaman Is 12.278°N, 93.858°E; summit elev. 354 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 13-14 September ash plumes from Barren Island rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted about 20-100 km W and
NE.

Geologic Summary. Barren Island, a possession of India in the Andaman
Sea about 135 km NE of Port Blair in the Andaman Islands, is the only
historically active volcano along the N-S-trending volcanic arc
extending between Sumatra and Burma (Myanmar). The 354-m-high island
is the emergent summit of volcano that rises from a depth of about
2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-
km-wide caldera with walls 250-350 m high. The caldera, which is open
to the sea on the W, was created during a major explosive eruption in
the late Pleistocene that produced pyroclastic-flow and -surge
deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course
of historical eruptions. Lava flows fill much of the caldera floor and
have reached the sea along the western coast during historical
eruptions.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Barren Island Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 9-11 and 14-15 September ash plumes from Batu Tara rose to an
altitude of 1.5 m (5,000 ft) a.s.l. and drifted 25-45 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the
Buenos Aires VAAC reported that on 15 September a diffuse ash plume
from Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex,
possibly mixed with steam and gas, rose to an altitude of 2.1 km
(7,000 ft) a.s.l. The plume drifted NE and SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 12 and 14 September ash plumes from Dukono rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 25-75 km W and SW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 10 and 14 September, INSIVUMEH reported that explosions from Fuego
produced ash plumes that rose to altitudes of 4.1-4.7 km
(13,500-15,400 ft) a.s.l. and drifted as far away as 10 km W, SW, and
S. Some explosions were accompanied by rumbling noises and shock
waves. Incandescent material was ejected 100 m high and avalanches
descended multiple ravines.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 9-15 September, HVO reported that lava flowed SE from

underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless
shield complex through a lava tube system, reaching the Waikupanaha

ocean entry. Weak, sporadic explosions from the ocean entry were seen
on 10 September. Occasional thermal anomalies detected in satellite
images and visual observations revealed active surface lava flows.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted mainly SW. The plume briefly turned brown on 9
September from a rockfall. Small amounts of ash were retrieved from
collection bins placed near the plume. Incandescence from small

openings in the floor of the vent, about 200 m below the Halema'uma'u

crater floor, was visible at night with varying intensity. During the
night from 12 to13 September, spattering from the opening was seen on
the web camera. The sulfur dioxide emission rate at the summit
remained elevated; 900 tonnes per day was measured on 11 September.

The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 11 and 14 September, INSIVUMEH reported that white and blue plumes
from Pacaya's MacKenney cone rose 300 m and drifted NW, S, and SW.
Multiple lava flows 75-250 m long traveled W.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 10-14 September emissions of steam and

gas from Popocatépetl contained slight amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 4-10 September gray ash and white plumes from
Rabaul caldera's Tavurvur cone rose 1.5 km above the crater. Ashfall
was reported in Rabaul town (3-5 km NW) and surrounding areas.

Occasionally, incandescence from the summit crater was seen at night,
and incandescent lava fragments were ejected from the crater. Rumbling

and roaring noises were reported. Several large explosions occurred
during an eight-hour period one unspecified evening. Based on analyses
of satellite imagery, the Darwin VAAC reported that during 11-13 and
15 September ash plumes rose to an altitude of 2.4 km (8,000 ft)
a.s.l. and drifted 35-130 km N and NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 9-15 September produced plumes that rose to
altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted S, SE, and
E.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 14 September, INSIVUMEH reported that an explosion from Santa
María's Santiaguito lava dome complex produced an ash plume that rose
to an altitude of 3.3 km (10,800 ft) a.s.l. The plume drifted SW and
cause ashfall downwind. Avalanches descended the SW flank of the dome.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SLAMET Central Java (Indonesia) 7.242°S, 109.208°E; summit elev. 3428
m

The Darwin VAAC reported that on 12 September a low-level ash plume
from Slamet was observed by a pilot. Ash was not identified on
satellite imagery.

Geologic Summary. Slamet, Java's second highest volcano at 3428 m and
one of its most active, has a cluster of about three dozen cinder
cones on its lower SE-NE flanks and a single cinder cone on the
western flank. Slamet is composed of two overlapping edifices, an
older basaltic-andesite to andesitic volcano on the west and a younger
basaltic to basaltic-andesite one on the east. Gunung Malang II cinder
cone on the upper eastern flank on the younger edifice fed a lava flow
that extends 6 km to the east. Four craters occur at the summit of
Gunung Slamet, with activity migrating to the SW over time. Historical
eruptions, recorded since the 18th century, have originated from a 150-
m-deep, 450-m-wide, steep-walled crater at the western part of the
summit and have consisted of explosive eruptions generally lasting a
few days to a few weeks.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Slamet Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 13-14 September. Details of possible resulting

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Sep 23, 2009, 6:17:41 PM9/23/09

to

SI / USGS Weekly VolcanicActivityReport

Sally Kuhn Sennert - Weekly Report Editor

http://www.volcano.si.edu/reports/usgs
16 September - 22 September 2009

New Activity/Unrest:

| Karymsky, Eastern Kamchatka
| Kliuchevskoi, Central Kamchatka (Russia)
| Sakar, Northeast of New Guinea (SW Pacific)
| Shiveluch, Central Kamchatka (Russia)

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Kilauea, Hawaii (USA)
| Rabaul, New Britain

| Reventador, Ecuador
| Sakura-jima, Kyushu
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see
the GVP Home Page for news of the latest
significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

On 22 September, KVERT raised the Level of Concern Color Code for
Karymsky to Yellow because seismic activity increased. The seismic
network likely detected ash bursts that possibly produced plumes that
rose to altitudes less than 2 km (6,600 ft) a.s.l.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that although seismic activity from Kliuchevskoi did
not exceed background levels during 11-18 September, weak tremor was
detected. Satellite imagery revealed a weak thermal anomaly over the
volcano from 13 to 17 September. Strombolian activity that ejected
tephra 70 m above the crater was seen at night on 16 and 17 September.
The Level of Concern Color Code was raised to Yellow.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKAR Northeast of New Guinea (SW Pacific) 5.414°S, 148.094°E; summit
elev. 992 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 18 September a possible diffuse ash plume from Sakar rose to an
altitude of 1.8 km (6,000 ft) a.s.l. and drifted 165 km NW. Four hours
later images showed that the volcano was clear; the plume may have
been smoke from a fire or steam. RVO was unable to confirm that an
eruption had or had not occurred.

Geologic Summary. Sakar is an incised stratovolcano with a summit
crater lake. Deep valleys cut the flanks of the volcano, which is
partially surrounded by coral reefs. An older volcano that forms much
of the island consists mainly of porphyritic basaltic rocks. A younger
andesitic cone with a 1.5-km-wide crater has been constructed within
the older volcano's larger crater, whose rim is exposed on the
northern and eastern sides. No historical eruptions are known from
Sakar, but warm springs are found along the SW coast, and a
pyroclastic cone on the southern flank of the 8 x 10 km wide island
may be of Holocene age.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Sakar Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 11-18 September seismic activity from

Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on
interpretations of seismic data, ash plumes possibly rose to an

altitude of 7.1 km (23,300 ft) a.s.l. On 13 September, pyroclastic
flow deposits 5 km long were seen on the S part of the lava dome.
Fumarolic activity was seen during 13 and 16-17 September, and hot
avalanches originated from the lava dome were seen at night on 16 and
17 September. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD, the Tokyo VAAC reported that on 19
September eruptions produced plumes that rose to an altitude of 5.2 km
(17,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 17-19 September ash plumes from Bagana rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 25-45 km NW, W, and SW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 16-19 and 21-22 September ash plumes from Batu Tara rose to an
altitude of 1.5 km (5,000 ft) a.s.l. and drifted 20-65 km W, NW, N,
and NE.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

During 1-16 September, SERNAGEOMIN reported that Chaitén's Domo Nuevo
1 and Domo Nuevo 2 lava-dome complex continued to grow. The Alert
Level remained at Red. Based on web camera views, SIGMET notices, and

analyses of satellite imagery, the Buenos Aires VAAC reported that

during 16 and 20-22 September ash plumes rose to altitudes of 1.8-2.4
km (6,000-8,000 ft) a.s.l. and drifted NE, E, and SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 17-20 September ash plumes from Dukono rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 25-75 km NE and ESE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 16-22 September, HVO reported that lava flowed SE from

underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless
shield complex through a lava tube system, reaching the Waikupanaha

ocean entry. Visual observations and thermal anomalies detected in
satellite images revealed active surface lava flows.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted mainly SW. Small amounts of ash were retrieved from
collection bins placed near the plume. The sulfur dioxide emission
rate at the summit remained elevated; 1,300, 1,000, and 400 tonnes per
day were measured on 16, 17, and 18 September, respectively. The
2003-2007 average rate was 140 tonnes per day. During 16 and 17
September, two hybrid earthquakes were followed by 20-40 minutes of
sustained tremor. The plume turned briefly "dusty" after the first
event and incandescent tephra was ejected onto the rim after the
second event; both produced glassy spatter.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 11-17 September gray ash plumes from Rabaul

caldera's Tavurvur cone rose 1.5 km above the crater. Ashfall was
reported in Rabaul town (3-5 km NW) and surrounding areas.
Occasionally, incandescence from the summit crater was seen at night,
and incandescent lava fragments were ejected from the crater. Rumbling

and roaring noises were reported. Several strong explosions occurred
on 11, 16, and 17 September, but were few or absent on other days.

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 21-22 September ash plumes rose to an altitude of 2.4 km (8,000
ft) a.s.l. and drifted 65-110 km NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

Based on a pilot observation, the Washington VAAC reported that on 21
September a plume from Reventador rose to an altitude of 7.6 km
(25,000 ft) a.s.l. Ash was not seen in satellite imagery, although
meteorological clouds were present.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 16, 18-19, and 21 September produced plumes
that rose to altitudes of 1.5-2.7 km (7,000-8,000 ft) a.s.l. and
drifted S, SW, W, NW, and NE. A pilot reported ash on 19 September.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA and pilot observations, the Tokyo VAAC
reported that on 17 September ash from Suwanose-jima drifted S. On 19
September, an ash plume rose to an altitude of 1.5 km (5,000 ft)
a.s.l.

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SI / USGS Weekly Volcanic Activity Report

New Volcanos Erupting This Week: 3 ~~ 12 Total Active

23 September-29 September 2009

Sally Kuhn Sennert - Weekly Report Editor

New Activity/Unrest:

| Dieng Volcanic Complex, Central Java (Indonesia)
| Karymsky, Eastern Kamchatka
| Shiveluch, Central Kamchatka (Russia)

This did not cover the 8.0 eathquake in American Samoa

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile
| Dukono, Halmahera
| Kilauea, Hawaii (USA)

| Langila, New Britain

| Rabaul, New Britain
| Redoubt, Southwestern Alaska
| Sakura-jima, Kyushu

| Turrialba, Costa Rica

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between

the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

DIENG VOLCANIC COMPLEX Central Java (Indonesia) 7.20°S, 109.92°E;
summit elev. 2565 m

CVGHM reported that on 26 September a "thunderous" noise from Dieng
was heard from 2 km away. The next day, a phreatic eruption from an
unspecified crater ejected mud as far away as 140 m S. The deposits
were as thick as 10 cm near the vent and 1 cm near the farthest point.
The Alert Level remained at 1 (on a scale of 1-4).

Geologic Summary. The Dieng plateau in the highlands of central Java
is renowned both for the variety of its volcanic scenery and as a
sacred area housing Java's oldest Hindu temples, dating back to the
9th century AD. The Dieng volcanic complex consists of two or more
stratovolcanoes and more than 20 small craters and cones of
Pleistocene-to-Holocene age over a 6 x 14 km area. Prahu stratovolcano
was truncated by a large Pleistocene caldera, which was subsequently
filled by a series of dissected to youthful cones, lava domes, and
craters, many containing lakes. Lava flows cover much of the plateau,
but have not occurred in historical time, when activity has been
restricted to minor phreatic eruptions. Toxic volcanic gas emission
has caused fatalities and is a hazard at several craters. The abundant
thermal features that dot the plateau and high heat flow make Dieng a
major geothermal prospect.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Dieng Volcanic Complex Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that on 17 and 22 September a weak thermal anomaly over
Karymsky was detected in satellite imagery. During 19-23 September
seismic activity was above background levels; analyses of the seismic
data indicated that ash plumes possibly rose to an altitude of 2 km
(6,600 ft) a.s.l. during 21-22 September, and to an altitude of 4.5 km
(14,800 ft) a.s.l. on 23 September. Scientists flying near Karymsky in
a helicopter on 22 September saw ash plumes that rose to an altitude
of 1.7 km (5,600 ft) a.s.l. and drifted E. The Level of Concern Color
Code was raised to Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 18-25 September seismic activity from

Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on

interpretations of seismic data, ash plumes possibly rose to an

altitude of 5.2 km (17,100 ft) a.s.l. According to video camera data
and visual observations, ash plumes rose to an altitude of 5.5 km
(18,000 ft) a.s.l. on 18, 19, and 22 September, and hot avalanches
from the lava dome were noted during 18 and 22-23 September. Ash
plumes were occasionally seen drifting 15-70 km N, NW, and SE. The

Level of Concern Color Code remained at Orange.

Based on information from KEMSD, the Tokyo VAAC reported that on 28
September an eruption produced a plume that rose to an altitude of 7
km (23,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 23-29 September ash plumes from Batu Tara rose to altitudes of
1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted 15-75 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the
Buenos Aires VAAC reported that on 28 September a diffuse ash plume

from Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex,

possibly mixed with steam and gas, rose to an altitude of 2.4 km
(8,000 ft) a.s.l. The plume drifted less than 40 km W and SW.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 24 September an ash plume from Dukono rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 65 km NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 23-27 September, HVO reported that lava flowed SE from

underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless
shield complex through a lava tube system, reaching the Waikupanaha

ocean entry. Lava was not seen entering the ocean on 28 and 29
September. Visual observations and thermal anomalies detected in
satellite images revealed active surface lava flows on most days. On
23 September, weak incandescence was detected from inside Pu'u 'O'o
crater and from a gas vent in the E crater wall. Explosive activity at
the ocean entry on 26 September was possibly caused by a small bench
collapse.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted SW and W. Small amounts of ash were retrieved from
collection bins placed near the plume. Weak incandescence from the

vent, about 200 m below the Halema'uma'u crater floor, was visible at

night. Rushing gas and rockfall sounds were occasionally heard in the
vicinity of the vent. Preliminary measurements indicated that the
sulfur dioxide emission rate at the summit remained elevated; 400,
700, and 665 tonnes per day were measured on 23, 24, and 28 September,
respectively. The 2003-2007 average rate was 140 tonnes per day. On 26
September, a series of rockfalls accompanied an apparent collapse of
the vent floor, causing the lava level to drop and the plume to turn
"dusty brown" for several minutes. On 28 September, a spattering lava
pond was seen inside the vent.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

LANGILA New Britain 5.525°S, 148.42°E; summit elev. 1330 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 29 September an ash plume from Langila rose to altitudes of 2.4-4.3
km (8,000-14,000 ft) a.s.l. and drifted 75-220 km NW.

Geologic Summary. Langila, one of the most active volcanoes of New
Britain, consists of a group of four small overlapping composite cones
on the lower eastern flank of the extinct Talawe volcano. Talawe is
the highest volcano in the Cape Gloucester area of NW New Britain. A
rectangular, 2.5-km-long crater is breached widely to the SE; Langila
volcano was constructed NE of the breached crater of Talawe. An
extensive lava field reaches the coast on the N and NE sides of
Langila. Frequent mild-to-moderate explosive eruptions, sometimes
accompanied by lava flows, have been recorded since the 19th century
from three active craters at the summit of Langila. The youngest and
smallest crater (no. 3 crater) was formed in 1960 and has a diameter
of 150 m.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Langila Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 18-24 September gray ash plumes from Rabaul

caldera's Tavurvur cone rose 1.5 km above the crater. Ashfall was
reported in Rabaul town (3-5 km NW) and surrounding areas.
Occasionally, incandescence from the summit crater was seen at night,
and incandescent lava fragments were ejected from the crater. Rumbling

and roaring noises were reported, although less frequently than during
11-17 September. Based on analyses of satellite imagery, the Darwin
VAAC reported that on 29 September an ash plume rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 75 km NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

On 29 September, AVO reported that seismic activity from Redoubt,
along with volcanic gas output, ground deformation, lava dome
temperatures, and outward signs of lava dome instability, have been
declining during the previous several months. The Volcanic Alert Level
was lowered to Normal and the Aviation Color Code was lowered to
Green.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 23, 25, and 27-29 September produced plumes
that rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and
drifted SW, W, and NW.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

On 25 September, scientists from OVSICORI-UNA reported results from
three field trips to Turrialba to inspect new fissures and to assess
the impact of gases on surrounding areas. Winds carrying toxic gases
10 km SW, to the S side of Irazú volcano, caused trees to exhibit mild
burns to a greater degree than effects from the previous year.
Vegetation within a 4-km-radius on the W, NW, and E flanks was also
burned more severely that previously noted. Several elongated fissures
in the rim S of the W crater were documented, as well as 1 km down
slope NW of the crater. One E-W-trending crack that was first seen
several months before had opened up as much as 12 cm, and emitted gas
and vapor at 90 degrees Celsius. On the NW lower flanks, at least
three radial fissures emitted high gas-and-vapor plumes. Some fissures
near the summit were 5-10 cm wide. The last of the remaining settlers
in the affected areas had moved away due to the intensification and
impact of the gases.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Observatorio Vulcanológico y Sismológico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Turrialba Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

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SI / USGS Weekly Volcanic Activity Report
New Volcanos Erupting This Week: 3 ~~ 12 Total Active

30 September-6 October 2009

Sally Kuhn Sennert - Weekly Report Editor

New Activity/Unrest:

| Chaitén, Southern Chile
| Cleveland, Chuginadak Island
| Galeras, Colombia
| Gaua, Banks Islands (SW Pacific)

| Karymsky, Eastern Kamchatka
| Kliuchevskoi, Central Kamchatka (Russia)

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

| Soufrière Hills, Montserrat

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Dukono, Halmahera
| Kilauea, Hawaii (USA)
| Langila, New Britain

| Popocatépetl, México

| Rabaul, New Britain
| Reventador, Ecuador

| Sangay, Ecuador
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays,
please see the GVP Home Page for
news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

During 16-30 September, SERNAGEOMIN reported that Chaitén's Domo Nuevo
1 (Phase I) and Domo Nuevo 2 (Phase II) lava-dome complex continued to
grow, generating block-and-ash flows from the collapse of unstable
slopes. Gas plumes continued to rise from the complex and were visible
using the web camera, S of the volcano.

On 29 September, people living in Chaitén town, 10 km SW, noticed that
the eruption column was larger. A dark area in the plume seen on the
web camera was interpreted to possibly be from collapse of part of the
lava dome to the SW. Scientists conducted an overflight and saw a
third lava dome (Phase III) in the SW area of the complex, which had
filled up a depression left by a collapse on 19 February. They also
noted a NNW-trending depression along the center of the lava domes
with spines at the N end, and that the central spine complex had
disappeared. Ash-and-gas plumes that occasionally rose 2 km above the
lava domes had two sources: one from the new dome and one from the
central depression. Several parts of the depressions circling the lava
domes had been filled in by collapsed material, and the depositional
area near the mouth of the Blanco River had also grown.

Based on web camera views, SIGMET notices, and analyses of satellite
imagery, the Buenos Aires VAAC reported that on 30 September and 3
October diffuse ash plumes, possibly mixed with steam and gas, rose to
an altitude of 2.4 km (8,000 ft) a.s.l. and drifted as far away as 55
km SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

A small explosive eruption of Cleveland on 2 October prompted AVO to
raise the Volcano Alert Level to Watch and the Aviation Color Code to
Orange. A detached ash cloud at estimated altitudes of 4.6-6.1 km
(15,000-20,000 ft) a.s.l. was seen on satellite imagery; the cloud
drifted about 600 km NE and dispersed over the Bering Sea. No further
activity was reported. On 5 October, the Volcano Alert Level was
lowered to Advisory and the Aviation Color Code was lowered to Yellow.
No seismic information was available because Cleveland does not have a
real-time seismic network.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

An explosive eruption from Galeras on 30 September prompted INGEOMINAS
to raise the Alert Level to I (Red; "imminent eruption or in
progress"). National Park personnel reported two explosions and
incandescent material ejected from the area of the active cone. An ash
plume rose to an approximate altitude of 12.3 km (40,400 ft) a.s.l.
and drifted E, then N. The sulfur dioxide emission rate was between
1,100 and 9,300 tons per day. Ash was deposited in Sandoná (15 km NW),
and Ancuya, Linares, and Sotomayor (40 km NW). Seismicity decreased
after the eruption. On 1 October, seismicity was low and the sulfur
dioxide emission rate was 300 tons per day. The Alert Level was
lowered to II (Orange; "probable eruption in term of days or weeks"),
and then to III (Yellow; "changes in the behavior of volcanic
activity") on 6 October.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

According to news articles from 2 October, increased seismicity at
Gaua was detected during the previous two weeks. Villagers living
nearby reported ashfall and sulfur odors. Both villagers and a pilot
flying past Gaua heard explosions. The Alert Level was raised to 1 (on
a scale of 0-5).

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Radio Australia

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was elevated above
background levels during 25 September-2 October and possibly indicated
weak ash explosions. Analyses of satellite imagery revealed a weak
thermal anomaly over the lava dome on 28 September; cloud cover
prevented observations on the other days. Scientists saw fumarolic
activity during an overflight on 1 October. The Level of Concern Color
Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's

eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 25 September-2 October seismic activity
from Kliuchevskoi was slightly above background levels and weak tremor
was detected. Satellite imagery revealed a weak thermal anomaly over
the volcano. Strombolian activity ejected tephra 70-100 m above the
crater during 28-30 September. The Level of Concern Color Code
remained at Yellow.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA and pilot observations, the Tokyo VAAC
reported that explosions from Sakura-jima during 30 September-6
October produced plumes that rose to altitudes of 1.8-4.3 km
(6,000-14,000 ft) a.s.l. Plumes occasionally drifted E, N, and W.

The JMA reported that explosions from Showa crater on 2 October
ejected incandescent tephra 800 m away from the rim. On 3 October,
Minami-dake crater exploded violently, producing an ash plume that
rose 3 km above the crater. Ballistics were ejected 1.7 km away. The
most recent previous explosion from the Minami-dake crater occurred on
22 February.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash
Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 25 September-2 October seismic activity

from Shiveluch was above background levels. Analyses of satellite
imagery revealed a large daily thermal anomaly over the lava dome.

Fumarolic activity was occasionally seen. Based on interpretations of
seismic data, ash plumes possibly rose to an altitude of 7 km (23,000
ft) a.s.l. on 27 September and to an altitude of 4.5 km (14,800 ft)
a.s.l. on other days. According to video camera data and visual
observations, ash plumes rose to an altitude of 4 km (13,100 ft)
a.s.l. on 28 September. An ash plume was seen on satellite imagery
drifting 65 km ESE on 29 September. The Level of Concern Color Code
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that a short volcano-tectonic earthquake swarm from
Soufrière Hills lava dome was detected at 2100 on 4 October. A period
of tremor and vigorous ash venting followed about an hour later. The
resulting ash plume drifted WNW across the island and out to sea,
causing ashfall in Old Towne and Olveston. The seismic signals
indicated no explosive activity or pyroclastic flows, but only two
rockfalls after the ash-venting event. During midnight to 0600 on 5
October, intermittent ash venting produced ash plumes that drifted
WNW. Two more "ash venting" events occurred at 1035 and 1325, without
precursory seismicity, producing ash plumes that rose to altitudes of
3-4.6 km (10,000-15,000 ft) a.s.l. Ash fell S of inhabited areas.
Based on information from MVO and analyses of satellite imagery, the
Washington VAAC reported that on 6 October several ash clouds rose to
altitudes of 3.7-5.5 km (12,000-18,000 ft) a.s.l. and drifted W.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash
Advisory Center (VAAC)

Soufrière Hills Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 30 September-3 October and 5-6 October ash plumes from Batu
Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 25-75

km W, NW, and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores

Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 2 October an ash plume from Dukono rose to an altitude of 2.7 km
(9,000 ft) a.s.l. and drifted 75 km NE. On 6 October, an ash plume
rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 55 km NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 30 September-6 October, HVO reported that lava flowed SE from

underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless
shield complex through a lava tube system, reaching the Waikupanaha

ocean entry. Thermal anomalies detected in satellite images revealed
active surface lava flows on top of the pali. The vent in Halema'uma'u
crater continued to produce a diffuse white plume that drifted SW.
Small amounts of occasional fresh ash were retrieved from collection
bins placed near the plume. During 30 September and 2, 4, and 5
October, a lava pond within the vent, about 200 m below the
Halema'uma'u crater floor, rose and fell, circulated, and weakly
spattered. Preliminary measurements indicated that the sulfur dioxide
emission rate at the summit remained elevated; 410, 650, and 480
tonnes per day were measured on 30 September, 1 and 2 October,

respectively. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that

comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

LANGILA New Britain 5.525°S, 148.42°E; summit elev. 1330 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 30 September an ash plume from Langila drifted 260 km NW at an
altitude of 4.3 km (14,000 ft) a.s.l. On 5 October, a diffuse ash
plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 185
km N.

Geologic Summary. Langila, one of the most active volcanoes of New
Britain, consists of a group of four small overlapping composite cones
on the lower eastern flank of the extinct Talawe volcano. Talawe is
the highest volcano in the Cape Gloucester area of NW New Britain. A
rectangular, 2.5-km-long crater is breached widely to the SE; Langila
volcano was constructed NE of the breached crater of Talawe. An
extensive lava field reaches the coast on the N and NE sides of
Langila. Frequent mild-to-moderate explosive eruptions, sometimes
accompanied by lava flows, have been recorded since the 19th century
from three active craters at the summit of Langila. The youngest and
smallest crater (no. 3 crater) was formed in 1960 and has a diameter
of 150 m.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Langila Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 3-6 October emissions of steam and gas

from Popocatépetl contained slight amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 25 September-1 October gray ash plumes from
Rabaul caldera's Tavurvur cone rose 2 km above the crater. Ashfall was

reported in Rabaul town (3-5 km NW) and surrounding areas.
Occasionally, incandescence from the summit crater was seen at night

and incandescent lava fragments were ejected from the crater. Based on
analyses of satellite imagery, the Darwin VAAC reported that on 6
October an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l.
and drifted 55 km NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

Based on information from IG, the Washington VAAC reported that on 4
October an ash plume from Reventador drifted W. Ash was not seen in
satellite imagery, although meteorological clouds were present. An
occasional thermal anomaly was seen, however.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 4 October a pilot saw an ash
plume from Sangay drifting W at altitudes of 5.2-7.6 km (17,000-25,000
ft) a.s.l. Meteorological clouds prevented satellite views of the
area. No additional reports of the ash plume were received by the
VAAC.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.

799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima on 1 October. A plume rose to an altitude of 1.5 km
(5,000 ft) a.s.l. and rifted W.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

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Oct 8, 2009, 10:23:50 PM10/8/09

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SI / USGS Weekly Volcanic Activity Report

New Volcanos Erupting This Week: 9 ~~ Total Active 18

New Activity/Unrest:

Ongoing Activity:

New Activity/Unrest

Map

Source: Radio Australia

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Oct 14, 2009, 6:45:42 PM10/14/09

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SI / USGS Weekly Volcanic Activity Report

New Volcanos Erupting This Week: 7 ~~ Total Active 15
7 October- 13 October 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

New Activity/Unrest:

| Karymsky, Eastern Kamchatka
| Kizimen, Eastern Kamchatka
| Kliuchevskoi, Central Kamchatka (Russia)
| Piton de la Fournaise, Reunion Island

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

Ongoing Activity:

| Arenal, Costa Rica
| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera

| Fuego, Guatemala

| Kilauea, Hawaii (USA)
| Rabaul, New Britain

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please
see the GVP Home Page for news of the
latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background
levels during 2-9 October and possibly indicated weak ash explosions.
On 7 October, field scientists saw an ash plume that rose to an
altitude of 3.5 km (11,500 ft) a.s.l. and drifted SSE. The Level of
Concern Color Code remained at Orange. Based on information from
KEMSD, the Tokyo VAAC reported that on 9 October an eruption produced
a plume that rose to an altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years

ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KIZIMEN Eastern Kamchatka 55.130°N, 160.32°E; summit elev. 2376 m

On 10 October, KVERT reported that seismicity from Kizimen was at
background levels in September, but began to increase in October,
especially on the 9th. A weak thermal anomaly was seen over the
volcano in satellite imagery on 17 and 21 September. The Level of

Concern Color Code was raised to Yellow.

Geologic Summary. Kizimen is an isolated, conical stratovolcano that

is morphologically similar to Mount St. Helens prior to its 1980
eruption. The summit of Kizimen consists of overlapping lava domes,
and blocky lava flows descend the flanks of the volcano, which is the
westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-
m-high Kizimen was formed during four eruptive cycles beginning about
12,000 years ago and lasting 2,000-3,500 years. The largest eruptions
took place about 10,000 and 8300-8400 years ago, and three periods of
longterm lava-dome growth have occurred. The latest eruptive cycle
began about 3,000 years ago with a large explosion and was followed by
lava-dome growth lasting intermittently about 1,000 years. An
explosive eruption about 1,100 years ago produced a lateral blast and
created a 1.0 x 0.7 km wide crater breached to the NE, inside which a
small lava dome (the fourth at Kizimen) has grown. A single explosive
eruption, during 1927-28, has been recorded in historical time.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kizimen Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 2-9 October seismic activity from
Kliuchevskoi was above background levels; many earthquakes and weak
tremor were detected. Satellite imagery revealed a weak thermal
anomaly over the volcano. During 2-3 October, Strombolian eruptions
sent tephra 70-100 m above the crater and fumarolic activity was
noted. On 7 October a fumarolic plume containing some ash rose to an
altitude of 5.7 km (19,700 ft) a.s.l. The Level of Concern Color Code
was raised to Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

During 5-6 October, OVPDLF reported increased seismicity from Piton de
la Fournaise. A seismic crisis on 7 October prompted OVPDLF to raise
the Alert Level to 1. Earthquakes were centered between the Bory and
Dolomieu craters, and deformation was detected on the N side of
Dolomieu. Seismicity remained above background levels during 8-13
October.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Sakura-jima during 7-12 October produced plumes that rose to
altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l. and drifted W, SW, S,
and SE. An explosion was also detected on 13 October.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 2-9 October seismic activity from Shiveluch
was above background levels. Analyses of satellite imagery revealed a
large daily thermal anomaly over the lava dome. According to video
camera data and visual observations, fumarolic plumes containing small
amounts of ash rose to an altitude of 4 km (13,100 ft) a.s.l. during
1-3 October. Based on interpretations of seismic data, possible ash
plumes rose to an altitude of 6.8 km (22,300 ft) a.s.l. on 6 October
and to an altitude of 4.5 km (14,800 ft) a.s.l. on other days. The

Level of Concern Color Code remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that ash-venting events from Soufrière Hills lava dome,
which had begun on 4 October, ceased in the early hours of 7 October;
there were a total of thirteen events. The last three were associated
with small pyroclastic flows that traveled about 500 m down Tyers
Ghaut to the NNW. Observations on 7 October revealed tongues of
rockfall and small pyroclastic-flow deposits at the heads of Tyers
Ghaut to the NNW, Tar River valley to the E, White River to the S, and
Gages to the W. A small area of incandescence from the N flank of the
lava dome was seen during 7-8 October.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during September activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian

eruptions, and occasional avalanches that traveled down the W flank.

Acid rain and small amounts of ejected pyroclastic material affected

the NE and SE flanks. Avalanches from lava-flow fronts traveled down
the SW flanks. Crater D produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 9 October an ash plume from Bagana rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 45 km SW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 6 October an ash plume from Batu Tara was seen drifting 65 km W at

an altitude of 2.4 km (8,000 ft) a.s.l.

Geologic Summary. The small isolated island of Batu Tara in the Flores

Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 7 October an ash plume from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 74 km NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 9, 12, and 13 October, INSIVUMEH reported that explosions from
Fuego produced ash plumes that rose to altitudes of 4.1-4.6 km
(13,500-15,100 ft) a.s.l. and drifted W. Some explosions were
accompanied by rumbling noises, and avalanches of blocks descended the
flanks. On 9 October, a lahar traveled down the Lajas ravine, carrying
blocks up to 50 cm in diameter.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 7-13 October, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry.
Thermal anomalies detected in satellite images revealed active surface

lava flows on top of the pali. Intermittent incandescence was seen
from Pu'u 'O'o crater and the East wall vent during 7-10 October.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted mainly SW. Small amounts of ash were retrieved from
collection bins placed near the plume. Incandescence originated from a
source deep inside the vent cavity; on 13 October a crusted lava pond
surface was seen. Preliminary measurements indicated that the sulfur
dioxide emission rate at the summit remained elevated; 800 tonnes per
day was measured on 11 October. The 2003-2007 average rate was 140
tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 2-8 October gray ash plumes from Rabaul

caldera's Tavurvur cone rose 2 km above the crater. Ashfall was
reported in Rabaul town (3-5 km NW) and surrounding areas.

Incandescence from the summit crater was occasionally visible. Based
on analyses of satellite imagery, the Darwin VAAC reported that on 9
October an ash plume rose to an altitude of 2.4 km (8,000 ft) a.s.l.
and drifted 75 km NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima on 10 and 11 October. A plume rose to an altitude of 1.5
km (5,000 ft) a.s.l. on 10 October.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

leona...@gmail.com

unread,

Oct 23, 2009, 10:40:19 PM10/23/09

to

SI / USGS Weekly Volcanic Activity Report

New Volcanos Erupting This Week: ~~ Total Active
14 October-20 October 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

New Activity/Unrest:

| Chaitén, Southern Chile
| Ebeko, Paramushir Island

| Gaua, Banks Islands (SW Pacific)

| Kaba, Sumatra (Indonesia)

| Kizimen, Eastern Kamchatka
| Kliuchevskoi, Central Kamchatka (Russia)

| Nevado del Huila, Colombia

| Piton de la Fournaise, Reunion Island

| Reventador, Ecuador
| Soufrière Hills, Montserrat

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)

| Cleveland, Chuginadak Island

| Dukono, Halmahera
| Karymsky, Eastern Kamchatka

| Kilauea, Hawaii (USA)
| Rabaul, New Britain

| Sakura-jima, Kyushu
| Sangay, Ecuador
| Shishaldin, Fox Islands
| Shiveluch, Central Kamchatka (Russia)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative
project between the Smithsonian's Global Volcanism
Program and the US Geological Survey's Volcano
Hazards Program.
Updated by 2300 UTC every Wednesday, notices of
volcanic activity posted on these pages are preliminary
and subject to change as events are studied in more detail.
This is not a comprehensive list of all of Earth's
volcanoes erupting during the week, but rather a summary
of activity at volcanoes that meet criteria discussed in
detail in the "Criteria and Disclaimers" section. Carefully
reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the
Global Volcanism Network.

Note: Many news agencies do not archive the
articles they post on the Internet, and therefore
the links to some sources may not be active.
To obtain information about the cited articles
that are no longer available on the Internet
contact the source.

New Activity/Unrest

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the
Buenos Aires VAAC reported that on 14 October an ash plume from
Chaitén's lava-dome complex rose to an altitude of 2.1 km (7,000 ft)
a.s.l. and drifted 150 km NNE. A diffuse plume was seen the next day
drifting 15 km SW at the same altitude as the previous day. During
15-16 October, a thermal anomaly was seen. On 18 October, a possible
plume drifted 50 km SE at an altitude of 2.1 km (7,000 ft) a.s.l.
Diffuse ash plumes possibly mixed with steam and gas rose to an
altitude of 1.8 km (6,000 ft) a.s.l. on 20 October and drifted NE and
SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

Based on analyses of satellite imagery, the Tokyo VAAC reported that
on 15 October a possible eruption plume from Ebeko rose to an altitude
of 10.7 km (35,000 ft) a.s.l. and drifted NE.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Ebeko Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

On 13 October, Vanuatu Geohazards Observatory confirmed that Gaua's
Mount Garat was erupting based on fieldwork done by scientists during
3-7 October. Seismic records showed multiple explosions, and a gas
flux measurement of 3,000 metric tons of sulfur dioxide was detected
on 3 October. The Alert Level was raised to 2 (on a scale of 0-5).

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Vanuatu Geohazards Observatory

Gaua Information from the Global Volcanism Program

KABA Sumatra (Indonesia) 3.52°S, 102.62°E; summit elev. 1952 m

On 20 October, CVGHM reported that seismic activity from Kaba
increased in August and remained elevated in September and October.
Inflation was also detected. When weather permitted, diffuse white
plumes were seen rising 25-50 m above the crater rim and drifting E.
Based on the deformation and increased seismicity, CVGHN raised the
Alert Level to 2 (on a scale of 1-4).

Geologic Summary.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Kaba Information from the Global Volcanism Program

KIZIMEN Eastern Kamchatka 55.130°N, 160.32°E; summit elev. 2376 m

KVERT reported that seismicity from Kizimen was above background
levels during 8-11 October and at background levels during 12-16
October. A weak thermal anomaly was seen at the volcano in satellite
imagery on 9 October. The Level of Concern Color Code remained at
Yellow.

Geologic Summary. Kizimen is an isolated, conical stratovolcano that
is morphologically similar to Mount St. Helens prior to its 1980
eruption. The summit of Kizimen consists of overlapping lava domes,
and blocky lava flows descend the flanks of the volcano, which is the
westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-
m-high Kizimen was formed during four eruptive cycles beginning about
12,000 years ago and lasting 2,000-3,500 years. The largest eruptions
took place about 10,000 and 8300-8400 years ago, and three periods of
longterm lava-dome growth have occurred. The latest eruptive cycle
began about 3,000 years ago with a large explosion and was followed by
lava-dome growth lasting intermittently about 1,000 years. An
explosive eruption about 1,100 years ago produced a lateral blast and
created a 1.0 x 0.7 km wide crater breached to the NE, inside which a
small lava dome (the fourth at Kizimen) has grown. A single explosive
eruption, during 1927-28, has been recorded in historical time.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kizimen Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 9-16 October seismic activity from
Kliuchevskoi was above background levels and weak tremor was detected.
Satellite imagery revealed a daily thermal anomaly at the volcano. On
11 October, Strombolian activity ejected tephra 200 m above the
crater. Fumarolic plumes containing small amounts of ash rose to an

altitude of 5.7 km (19,700 ft) a.s.l. The Level of Concern Color Code

remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active

volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

Based on web camera views, INGEOMINAS reported that on 16 October an
ash plume from Nevado del Huila rose 1 km and drifted E. Ashfall and
sulfur odors were reported in several surrounding areas. Later that
day, seismicity increased, prompting INGEOMINAS to raise the Alert
Level to II (Orange; "probable eruption in term of days or weeks").

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Huila Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

On 14 October, OVPDLF reported a seismic crisis from Piton de la
Fournaise, with seismicity indicating deformation on the N side of
Dolomieu crater and rockfalls within the crater. During 15-17 October,
deformation and rockfalls continued to be detected. On 18 October,
another seismic crisis was noted along with deformation on the N and S
sides of Dolomieu crater. Aerial observations on 19 October revealed a
small new fumarole in the crater. Changes in the chemical composition
of the gases were also noted. A greater number and duration of
rockfalls than in previous days was detected on 20 October.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The IG reported that field observations of Reventador on 16 and 17
September confirmed the presence of a lava flow on the S flank of the
cone. Gas and steam emissions were noted, as was growth of the lava
dome. Thermal anomalies over the crater area were detected in
satellite imagery on 6, 11, and 13 October. On 14 October, seismicity
increased and harmonic tremor was detected. A seismic station on the
NE flank of the cone detected rockfalls. Several people living in the
area reported roaring noises and observed slight incandescence from
the crater during the previous few nights.

During an overflight on 16 October, scientists saw the lava dome and a
lava flow on the N flank. Bluish gases were emitted. According to a
thermal camera, the incandescent parts in the crater were about 300
degrees Celsius. Other observers heard roaring noises and sounds
resembling "cannon shots." Incandescent blocks were ejected from the
crater, and steam and gases rose 100 m and drifted SW. Incandescent
material was seen on the S flank. On 17 October, incandescence on the
S flank was seen and noises similar the previous day were again heard.
A small gray plume was seen the next day. On 19 October, thermal
anomalies were again detected on satellite imagery. During an
overflight, blue gas plumes were seen. The lava flow on the S flank
occupied a large area and was divided into two branches.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Reventador Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 9-16 October activity from the Soufrière
Hills lava dome was at a high level; a new lava dome first reported on
9 October continued to grow. Over 1,200 rockfalls were detected by the
seismic network. Pyroclastic flows traveled down every major drainage
valley except the Tar River valley to the E. Brief views of the lava
dome revealed that the new lava dome summit was about 60 m above the
old dome structure. Heavy rainfall caused a lahar in the Belham Valley
to the NW on 14 October. On 16 October, several large pyroclastic
flows descended the White River to the S and reached the sea. Moderate-
sized pyroclastic flows traveled 3 km NE down Tuitts Ghaut and White
Bottom Ghaut, and a few smaller pyroclastic flows descended Tyers
Ghaut to the N. Extensive ash clouds rose to an altitude of km (20,000
ft) a.s.l. and drifted WNW, resulting in minor ashfall in inhabited
areas. During 18-19 October, rockfalls and small pyroclastic flows
continued to be detected.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 15 October an ash plume from Bagana rose to an altitude of 2.1 km
(7,000 ft) a.s.l. and drifted 55 km SW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 14-16 October ash plumes from Batu Tara were seen drifting
25-185 km W and N at an altitude of 1.8 km (6,000 ft) a.s.l.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

On 19 October, AVO reported that no eruptive activity from Cleveland
had been observed since the brief eruption on 2 October. The Aviation
Color Code and the Volcano Alert Level were lowered to Unassigned.
Cleveland is not monitored by a real-time seismic network, thus the
levels "Green" or "Normal" do not apply because background activity is
not defined.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 15 October an ash plume from Dukono rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 45 km NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was elevated above
background levels during 9-16 October and possibly indicated that ash
plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. On 12 October,
volcanologists doing fieldwork saw an ash plume rise to an altitude of
3.5 km (11,500 ft) a.s.l. The Level of Concern Color Code remained at

Orange. Based on information from KEMSD, the Tokyo VAAC reported that

on 20 October eruptions produced plumes that rose to altitudes of
3-3.7 km (10,000-12,000 ft) a.s.l. Ash was not identified on satellite
imagery.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 14-20 October, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry.

Thermal anomalies detected in satellite images and visual observations
revealed active surface lava flows on top and at the base of the pali.
Intermittent incandescence was seen from the Pu'u 'O'o crater floor
and an East wall vent.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted SW. Fresh Pele's Hair was collected near the summit
on 16 October. Incandescence originated from sources inside the vent
cavity; on 18 October a lava pond surface was seen, but then
disappeared. Preliminary measurements indicated that the sulfur
dioxide emission rate at the summit remained elevated; 690-940 tonnes
per day was measured during 16-18 October. The 2003-2007 average rate

was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 15, 18, and 20 October ash plumes from Rabaul caldera's Tavurvur
cone rose to altitudes of 2.7-3 km (9,000-10,000 ft) a.s.l. and
drifted 25-85 km NW, W, and NE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 13-20 October produced plumes that rose to
altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted SW, S, SE,
and E. On 15 October, a pilot reported that an ash plume rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 15 October a small plume from Sangay drifted 15 km SW.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHISHALDIN Fox Islands 54.756°N, 163.97°W; summit elev. 2857 m

On 19 October, AVO reported that recent clear satellite views of
Shishaldin showed no activity; the last thermal anomaly was detected
on 16 August. Seismicity was variable, but within background levels.
The Aviation Color Code was lowered to Green and the Volcano Alert
Level was lowered to Normal.

Geologic Summary. The beautifully symmetrical volcano of Shishaldin is
the highest and one of the most active volcanoes of the Aleutian
Islands. The 2,857-m-high, glacier-covered volcano is the westernmost
of three large stratovolcanoes along an E-W line in the eastern half
of Unimak Island. Constructed atop an older glacially dissected
volcano, Shishaldin is Holocene in age and largely basaltic in
composition. Remnants of an older ancestral volcano are exposed on the
W and NE sides at 1,500-1,800 m elevation. Shishaldin contains over
two dozen pyroclastic cones on its NW flank, which is blanketed by
massive aa lava flows. Frequent explosive activity, primarily
consisting of Strombolian ash eruptions from the small summit crater,

sometimes producing lava flows, have been recorded since the 18th
century.

Map

Source: Alaska Volcano Observatory (AVO)

Shishaldin Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 9-16 October seismic activity from
Shiveluch was above background levels and possibly indicated that ash
plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. Analyses of
satellite imagery revealed a large thermal anomaly over the lava dome
during 8-13 and 15 October. Fumarolic plumes containing small amounts
of ash rose to an altitude of 3.5 km (11,500 ft) a.s.l. during 11-13
October. According to video camera data and visual observations,
multiple hot avalanches traveled down the lava dome on 12, 13, and 14
October, and deposits from a small pyroclastic flow on the SE flank
were noted. The Level of Concern Color Code remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

leona...@gmail.com

unread,

Nov 5, 2009, 4:43:34 PM11/5/09

to

SI / USGS Weekly VolcanicActivityReport

New Volcanos Erupting This Week: ~~ Total Active
28 October- 3 November 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Ebeko, Paramushir Island
| Galeras, Colombia

| Karangetang [Api Siau], Siau I

| Manam, Northeast of New Guinea (SW Pacific)
| Nevado del Huila, Colombia
| Soufrière Hills, Montserrat

OngoingActivity:

| Barren Island, Andaman Is
| Chaitén, Southern Chile

| Dukono, Halmahera
| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)

| Kliuchevskoi, Central Kamchatka (Russia)
| Krakatau, Indonesia
| Popocatépetl, México

| Rabaul, New Britain
| Sakura-jima, Kyushu

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the

GVP Home Page for news of the latest significant activity.

The Weekly VolcanicActivityReport is a cooperative

project between the Smithsonian's Global Volcanism
Program and the US Geological Survey'sVolcano
Hazards Program.
Updated by 2300 UTC every Wednesday, notices of

volcanicactivityposted on these pages are preliminary

and subject to change as events are studied in more detail.
This is not a comprehensive list of all of Earth's
volcanoes erupting during the week, but rather a summary

ofactivityat volcanoes that meet criteria discussed in

detail in the "Criteria and Disclaimers" section. Carefully
reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the
Global Volcanism Network.

Note: Many news agencies do not archive the
> articles they post on the Internet, and therefore
> the links to some sources may not be active.
> To obtain information about the cited articles
> that are no longer available on the Internet
> contact the source.

NewActivity/Unrest:

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

KVERT reported that on 26 October a gas-and-steam plume from Ebeko was
seen by observers in Severo-Kurilsk, about 7 km E of Ebeko, rising 300
m above the crater and drifting 1-2 km NNE. There was no evidence of
ash deposits on the snow cover. Gas-and-steam plumes rose 250 m above
the crater and drifted 2 km E on 28 October and NNE on 29 October. The
Level of Concern Color Code remained at Green.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Ebeko Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

On 30 October, INGEOMINAS reported that the Alert Level for Galeras
was raised to II (Orange; "probable eruption in term of days or
weeks"). Since 27 October, degassing decreased and seismicity
increased, reflecting conditions seen prior to previous eruptions. On
3 November, INGEOMINAS stated that gas emissions had been low during
the previous days, and seismicity had decreased that day.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m

Based on a pilot observation and analyses of satellite imagery, the
Darwin VAAC reported that on 3 November an ash plume from Karangetang
rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 90-185 km
W.

Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi, and contains five
summit craters strung along a N-S line. One of Indonesia's most active
volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Karangetang [Api Siau] Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 1-2 November ash plumes from Manam rose to an altitude of 2.1
km (7,000 ft) a.s.l. and drifted 35-55 km NW and N.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Manam Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that on 28 October a pulse of tremor from Nevado
del Huila was followed by an ash plume that, according to the
Washington VAAC, rose to an altitude of 8.3 km (27,200 ft) a.s.l. On
30 October and 2 November overflights revealed a high rate of lava
dome growth compared to the previous observation on 23 October. An ash
layer covered the W part of Pico Central. Continuous and intense
degassing originated from areas that also exhibited thermal anomalies
detected with a thermal imaging camera. Resulting gas plumes drifted
NW. The volume estimate for the new lava dome was nearly 9 million
cubic meters.

Based on analyses of satellite imagery, pilot observations, and web
camera views, the Washington VAAC reported that on 31 October an ash
plume drifted 65 km S. During 31 October-2 November, thermal anomalies
were seen on satellite imagery. On 2 November, a small plume seen on
the web camera drifted SE. Gas plumes, occasionally accompanied by ash
plumes, drifted 35 km SE.

On 3 November, INGEOMINAS reported that a pulse of tremor was followed
by an ash plume that, according to the VAAC, rose to an altitude of
11.3 km (37,100 ft) a.s.l. and drifted SW. Ashfall was reported in
communities downwind. The VAAC also noted that another ash plume rose
to an altitude below 6.7 km (22,000 ft) a.s.l. and drifted E.
INGEOMINAS stated that residents of Mosoco (20 km SSW) saw collapses
from the W side of the dome generate small pyroclastic flows and
incandescence at night. The Alert Level remained at II (Orange;

"probable eruption in term of days or weeks").

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),

Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 23-30 October seismic activity from the
Soufrière Hills lava dome was at a slightly lower level that the
previous week. Numerous pyroclastic flows occurred in most of the
major drainage valleys and rockfalls were concentrated in the S. Heavy
rainfall caused lahars in the Belham Valley to the W. On 28 October,
two pyroclastic flows traveled 2 km W down Gages Valley. On 29
October, a 40-m-high spine was seen protruding from the summit.
Changes in lava-dome morphology seen on 30 October, and occurrences of
pyroclastic flows traveling NE, indicated that growth was concentrated
in the central part of the lava dome. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

Ongoing Activity

BARREN ISLAND Andaman Is 12.278°N, 93.858°E; summit elev. 354 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 1 November an ash plume from Barren Island rose to an altitude of
1.8 km (6,000 ft) a.s.l. and drifted about 55-75 km W.

Geologic Summary. Barren Island, a possession of India in the Andaman
Sea about 135 km NE of Port Blair in the Andaman Islands, is the only
historically active volcano along the N-S-trending volcanic arc
extending between Sumatra and Burma (Myanmar). The 354-m-high island
is the emergent summit of volcano that rises from a depth of about
2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-
km-wide caldera with walls 250-350 m high. The caldera, which is open
to the sea on the W, was created during a major explosive eruption in
the late Pleistocene that produced pyroclastic-flow and -surge
deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course
of historical eruptions. Lava flows fill much of the caldera floor and
have reached the sea along the western coast during historical
eruptions.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Barren Island Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on analyses of satellite imagery, the Buenos Aires VAAC reported
that on 30 October a diffuse ash plume from Chaitén's lava-dome
complex rose possibly mixed with steam and gas drifted SSE. On 1
November, a plume drifted 20 km W.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 31 October an ash plume from Dukono rose to an altitude of 1.5 km
(5,000 ft) a.s.l. and drifted 35-110 km NE and N.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background
levels during 23-27 and 30 October, a possible indication that ash
plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. No seismic
data was available on 22 and 28 October. Analyses of satellite imagery
revealed an ash plume that drifted 120 km E on 23 October, and a
thermal anomaly during 23-26 and 29 October. The Level of Concern
Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 21-27 October, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex

through a lava tube system, reaching the Waikupanaha ocean entry. Lava
began entering the ocean at a second location, 700 m farther to the W,
on 31 October. Thermal anomalies detected in satellite images and
visual observations revealed active surface lava flows. Breakout lava
flows were located inland of the Waikpuanaha entry and also
immediately W of the County Public Viewing trail. Intermittent

incandescence was seen from the Pu'u 'O'o crater floor and an East
wall vent.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted SW. Incandescence originated from occasionally
spattering holes from a surface inside the vent cavity. On 3 November,
a collapse of the surface revealed a circulating and spattering lava
pond below. Preliminary measurements indicated that the sulfur dioxide
emission rate at the summit remained elevated; 800 tonnes per day was
measured on 30 October. The 2003-2007 average rate was 140 tonnes per
day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 23-30 October seismic activity from
Kliuchevskoi was above background levels; tremor increased on 26
October. Strombolian activity ejected tephra 200 m above the crater
and fumarolic activity was occasionally noted. Satellite imagery
revealed a daily thermal anomaly at the volcano. The Level of Concern

Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

KRAKATAU Indonesia 6.102°S, 105.423°E; summit elev. 813 m

CVGHM reported that from August to 29 October seismicity from Anak
Krakatau, and the occurrence of eruption plumes, decreased. The Alert
Level was lowered to 2 (on a scale of 1-4).

Geologic Summary. Renowned Krakatau volcano lies in the Sunda Strait
between Java and Sumatra. Collapse of the ancestral Krakatau edifice,
perhaps in 416 AD, resulted in a 7-km-wide caldera. Remnants of this
volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan
and Perbuwatan volcanoes were formed, coalescing to create the
pre-1883 Krakatau Island. Caldera collapse during the catastrophic
1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only
a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau
(Child of Krakatau), constructed within the 1883 caldera at a point

between the former cones of Danan and Perbuwatan, has been the site of
frequent eruptions since 1927.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Krakatau Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that on 29 October a small explosive event from
Popocatépetl produced an ash plume that rose to an altitude of 6.4 km
(21,000 ft) a.s.l.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 28-29 October ash plumes from Rabaul caldera's Tavurvur cone
rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 35-45 km
N, E, and SE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 28 October-3 November produced plumes that
rose to altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l. Some plumes
drifted W, SW, S, SE, and NE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 23-30 October seismic activity from

Shiveluch was above background levels and possibly indicated that ash

plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. and to an
altitude of 6.9 km (22,600 ft) a.s.l. on 29 October. Fumarolic
activity was occasionally seen. Analyses of satellite imagery revealed
a large thermal anomaly over the lava dome during 22-27 October and an
ash plume that drifted 24 km NE on 26 October. Based on information
from KEMSD and analyses of satellite imagery, the Tokyo VAAC reported
that on 30 October an eruption produced a plume that rose to an
altitude of 7 km (23,000 ft) a.s.l. A possible eruption plume rose to
an altitude of 6.1 km (20,000 ft) a.s.l. later that day. On 1
November, an eruption produced a plume that rose to an altitude of 4.9
km (16,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima on 30 October and 2 November. Details of possible
resulting emissions were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

leona...@gmail.com

unread,

Nov 12, 2009, 10:12:28 PM11/12/09

to

SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: ~~ Total Active
4 November - 10 November 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Batur, Bali (Indonesia)

| Galeras, Colombia
| Karangetang [Api Siau], Siau I

| Mayon, Luzon

| Nevado del Huila, Colombia
| Piton de la Fournaise, Reunion Island
| Reventador, Ecuador

| San Vicente, El Salvador

OngoingActivity:

| Koryaksky, Eastern Kamchatka

| Rabaul, New Britain |
Sakura-jima, Kyushu

| Santa María, Guatemala

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significantactivity.

The Weekly VolcanicActivityReport is a cooperative
project between the Smithsonian's Global Volcanism
Program and the US Geological Survey'sVolcano
Hazards Program.

Updated by 2300 UTC every Wednesday, notices of
volcanicactivityposted on these pages are preliminary
and subject to change as events are studied in more detail.
This is not a comprehensive list of all of Earth's
volcanoes erupting during the week, but rather a summary
ofactivityat volcanoes that meet criteria discussed in
detail in the "Criteria and Disclaimers" section. Carefully
reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the
Global Volcanism Network.

Note: Many news agencies do not archive the
articles they post on the Internet, and therefore
the links to some sources may not be active.
To obtain information about the cited articles
that are no longer available on the Internet
contact the source.

NewActivity/Unrest:

BATUR Bali (Indonesia) 8.242°S, 115.375°E; summit elev. 1717 m

CVGHM reported increased seismicity from Batur from September to 7
November and a significant increase in the number of volcanic
earthquakes on 8 November. The Alert Level was raised to 2 (on a scale
of 1-4).

Geologic Summary. The historically active Batur volcano is located at
the center of two concentric calderas NW of Agung volcano in eastern
Bali. The SE side of the larger 10 x 13 km caldera contains a caldera
lake. The inner 7.5-km-wide caldera, which was formed during
emplacement of the Bali (or Ubud) ignimbrite, has been dated at either
23,670 or 28,500 years ago. The SE wall of the inner caldera lies
beneath Lake Batur; Batur cone has been constructed within the inner
caldera to a height above the outer caldera rim. The Batur
stratovolcano has produced vents over much of the inner caldera, but a
NE-SW fissure system has localized the Batur I, II, and III craters
along the summit ridge. Historical eruptions have been characterized
by mild-to-moderate explosive activity sometimes accompanied by lava
flows from summit and flank vents that have reached the caldera floor
and the shores of Lake Batur.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Batur Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

INGEOMINAS reported that during 7-10 November seismic activity from
Galeras decreased, although some seismic signals resembled patterns
seen prior to previous eruptions. Sulfur dioxide emissions were not
detected. The Alert Level remained at II (Orange; "probable eruption

in term of days or weeks").

Geologic Summary. Galeras, a stratovolcano with a large breached

caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m

According to news articles, a pyroclastic flow and a lahar descended
the flanks of Karangetang on 4 November. Residents saw active lava
flows the next day. On 11 November, incandescent material was ejected
5 m into the air.

Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi, and contains five
summit craters strung along a N-S line. One of Indonesia's most active
volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Sources: Manado Post, Berita

Karangetang [Api Siau] Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

PHIVOLCS reported that on 11 November an explosion from Mayon's summit
crater ejected incandescent rock fragments that were seen from nearby
areas. Cloud cover prevented observations of an ash plume, however
field investigations after the event revealed ashfall to the SW. The

Alert Level remained at 2 (on a scale of 0-5). The 7-km Extended
Danger Zone (EDZ) on the SE flank and the 6-km Permanent Danger Zone
(PDZ) in all other areas remained in effect.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Mayon Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that overflights of Nevado del Huila on 4, 6, and
10 November revealed a continued high rate of lava dome growth; the
volume estimate for the new lava dome was nearly 25 million cubic
meters. Small collapses occurred on the W part of the dome. Gas
emissions were sometimes accompanied by pulsating ash emissions.
Sulfur dioxide plumes rose 2.5 km above the lava dome and were seen in
satellite imagery and the web camera drifting with the prevailing
winds. The Alert Level remained at II (Orange; "probable eruption in

term of days or weeks").

Based on analyses of satellite imagery, the Washington VAAC reported
that during 4-6 and 10 November thermal anomalies on the volcano were
seen intermittently through cloud cover. On 7 November, Bogota MWO
reported an ash plume at an altitude of 9.4 km (31,000 ft) a.s.l., and
a plume was seen drifting ESE on satellite imagery. Later that day, an
ash plume was seen on satellite imagery and on the web cameras
drifting SE at an altitude below 7.3 km (24,000 ft) a.s.l.

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),
Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

OVPDLF reported that on 5 November a vent inside the S part of Piton
de la Fournaise's Dolomieu crater opened, following an intense seismic
crisis. Within thirty minutes, a fissure on the upper SE flank
propagated E and a second fissure opened on the E flank. Lava
fountains 20 m high and 'a'a lava flows were emitted from both
fissures. The Alert Level was raised to 2. Lava flows ceased by the
morning of 6 November; the Alert level was lowered to 1 later that
day.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

Based on a pilot observation, the Washington VAAC reported that on 5
November an ash plume from Reventador rose to an altitude of 7 km
(23,000 ft) a.s.l. and drifted NE. Ash was not seen in satellite
imagery, although meteorological clouds were present. IG reported that
an ash plume rose 500 m above the crater on 7 November.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),

Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SAN VICENTE El Salvador 13.595°N, 88.837°W; summit elev. 2182 m

According to news articles, heavy rains caused landslides and flooding
in the town of Verapaz, about 6 km NW of the summit of San Vicente,
during 7-8 November. Mud and boulders swept down the flanks San
Vicente, and in conjunction with flooded rivers, buried homes and
cars; at least 144 people were killed and about 60 were missing.

Geologic Summary. The twin peaks of San Vicente volcano, also known as
Chichontepec, rise dramatically to the SE of Lake Ilopango. The modern
stratovolcano was constructed within the Pleistocene La Carbonera
caldera, whose rim is visible only on its SW side. San Vicente
volcano, the second highest in El Salvador, grew within the caldera to
form a paired volcano with summit craters along a WSW-ENE line. The
northern and southern flanks are covered by lava flows from the
central vent, but lava flows on the eastern side originated from a
vent on the upper flank. Volcanism has continued into the Holocene,
but the latest lava flows are covered by deposits from the major ca.
260 AD eruption from neighboring Ilopango volcano. Reports of
historical eruptions in 1643 and 1835 are false, but numerous hot
springs and fumaroles are found on the northern and western flanks of
the volcano.

Map

Sources: Associated Press, Associated Press

San Vicente Information from the Global Volcanism Program

Ongoing Activity

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that Chaitén's lava-dome complex continued to
grow during 16-30 October. The Alert Level remained at Red.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 8 November an ash plume from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 35 km NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background

levels during 29-31 October; data was not collected during 1-4
November due to technical reasons. Seismic signals possibly indicated
that ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. on 31
October and 5 November. Analyses of satellite imagery during 29
October-5 November revealed almost daily thermal anomalies and
intermittent ash plumes that drifted 180 km E. The Level of Concern
Color Code remained at Orange. Based on information from KEMSD, the
Tokyo VAAC reported that eruptions on 8 and 10 November produced
plumes that rose to altitudes of 3-3.4 km (10,000-11,000 ft) a.s.l.

Ash was not identified on satellite imagery.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's

eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 4-10 November, HVO reported that lava flowed SE from underneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex

through a lava tube system, reaching the Waikupanaha ocean entry and a
second location, 700 m farther to the W. Thermal anomalies detected in

satellite images and visual observations revealed active surface lava
flows. Breakout lava flows were located inland of the Waikpuanaha

entry and also W of the County Public Viewing trail. The last
remaining structure on the flow field burned on 3 November.
Incandescence was seen from the Pu'u 'O'o crater floor and an East
wall vent during 6-7 November.

The vent in Halema'uma'u crater continued to produce a diffuse white

plume that drifted SW and likely produced some ashfall. Incandescence
originated from a spattering lava pond inside the vent cavity.

Preliminary measurements indicated that the sulfur dioxide emission

rate at the summit remained elevated; 700 and 400 tonnes per day were
measured on 6 and 9 November, respectively. The 2003-2007 average rate

was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 30 October-6 November seismic activity from
Kliuchevskoi was above background levels. Strombolian activity ejected
tephra 300 m above the crater and fumarolic activity was occasionally

noted. Satellite imagery revealed a daily thermal anomaly at the
volcano. The Level of Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

KORYAKSKY Eastern Kamchatka 53.320°N, 158.688°E; summit elev. 3456 m

KVERT reported that during 30 October-6 November seismic activity from
Koryaksky did not exceed background levels. Fumarolic activity was
noted on 29 October and during 4-5 November. The Level of Concern

Color Code was lowered to Green.

Geologic Summary. The large symmetrical Koryaksky stratovolcano is the

most prominent landmark of the NW-trending Avachinskaya volcano group,
which towers above Kamchatka's largest city, Petropavlovsk. Erosion
has produced a ribbed surface on the eastern flanks of the 3456-m-high
volcano; the youngest lava flows are found on the upper western flank
and below SE-flank cinder cones. No strong explosive eruptions have
been documented during the Holocene. Extensive Holocene lava fields on
the western flank were primarily fed by summit vents; those on the SW
flank originated from flank vents. Lahars associated with a period of
lava effusion from south- and SW-flank fissure vents about 3900-3500
years ago reached Avacha Bay. Only a few moderate explosive eruptions
have occurred during historical time. Koryaksky's first historical
eruption, in 1895, also produced a lava flow.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Koryaksky Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 9 November an ash plume from Rabaul caldera's Tavurvur cone rose to
an altitude of 1.8 km (6,000 ft) a.s.l. and drifted 110 km NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 4-10 November produced plumes that rose to
altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted in
multiple directions. Pilots reported ash plumes that rose to an
altitude of 2.4 km (8,000 ft) a.s.l. on 5 November and to an altitude
of 1.2 km (4,000 ft) a.s.l. on 9 November. Plumes drifted E and N,
respectively. According to a news article, Sakura-jima exploded for
the 400 th time in 2009 on 5 November.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Japan Times

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 6 November, INSIVUMEH reported that an explosion from Santa María's
Santiaguito lava dome complex produced a plume that rose 900 m and
drifted SW. Based on analyses of satellite imagery, the Washington
VAAC reported that on 8 November a small gas plume possibly containing
ash drifted less than 10 km SSW. Another small plume was seen later
that day.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 30 October-6 November seismic activity from

Shiveluch was above background levels and possibly indicated that ash

plumes rose to an altitude of 4.7 km (15,400 ft) a.s.l. Fumarolic
activity was noted and analyses of satellite imagery revealed a large
thermal anomaly over the lava dome. According to video camera data,
ash plumes rose to an altitude of 8 km (26,400 ft) a.s.l. on 30
October. Ash plumes seen on satellite imagery drifted 130-255 km E on
30 October, and 1 and 5 November. The Level of Concern Color Code
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 30 October-6 November activity from the
Soufrière Hills lava dome was at a high level; hybrid earthquakes were
recorded for the first time since the renewal of activity in early
October. Numerous pyroclastic flows occurred in most of the major
drainage valleys. On 4 November, pyroclastic flows were seen from a
helicopter traveling SW down Gingoes Ghaut to within 200 m of the sea.
The frequency of pyroclastic flows increased on 5 November and
particularly vigorous flows occurred in Tuitt's Ghaut to the NE. Ash
fell in inhabited areas on a few occasions. Lahars descended the
Belham Valley to the W several times. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Suwanose-jima during 4-5 November produced plumes that rose to
altitudes of 1.2-1.8 km (4,000-6,000 ft) a.s.l. and drifted SW and W.
An explosion was also reported on 6 November.

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SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: ~~ Total Active

11 November - 17 November 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Galeras, Colombia
| Mayon, Luzon

OngoingActivity:

| Arenal, Costa Rica
| Bagana, Bougainville

| Chaitén, Southern Chile
| Fuego, Guatemala

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)

| Kizimen, Eastern Kamchatka
| Kliuchevskoi, Central Kamchatka (Russia)
| Nevado del Huila, Colombia

| Popocatépetl, México
| Rabaul, New Britain

| Reventador, Ecuador
| Sakura-jima, Kyushu
| Sangay, Ecuador

NewActivity/Unrest:

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

INGEOMINAS reported that an overflight of Galeras on 14 November
revealed thermal anomalies in the main crater measuring 110 degrees
Celsius and very low rates of gas discharge. The Alert Level remained

at II (Orange; "probable eruption in term of days or weeks").

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

According to news articles, an explosion from Mayon on 11 November
prompted authorities to evacuate about 700 families from nearby areas.
Incandescence from the crater at night on 14 November was visible from
15 km away.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: The Philippine Star

Mayon Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during October activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian

eruptions, and occasional avalanches that traveled down the W and SW
flanks. Acid rain and small amounts of ejected pyroclastic material

affected the NE and SE flanks. Avalanches from lava-flow fronts
traveled down the SW flanks. Crater D produced only fumarolic
activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 12 November an ash plume from Bagana rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 65 km SW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 31 October-1 November Chaitén's lava-
dome complex produced steam plumes that sometimes contained gas and
ash. The plumes were visible on the web camera and rose at most 1 km
above the lava domes. The Alert Level remained at Red.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Chaitén Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 12 November a gas plume from Fuego, possibly containing ash,
drifted SSW. On 13 November, INSIVUMEH reported that explosions
produced ash plumes that rose to altitudes of 4.2-4.7 km
(13,800-15,400 ft) a.s.l. and drifted 7 km S. Rumbling noises were
noted and incandescence was detected. White fumarolic plumes rose 100
m and drifted S and SW. Small plumes of ash on 16 November were seen
on satellite imagery.

Geologic Summary. Volcán Fuego, one of Central America's most active

volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background

levels during 5-9 November, a possible indication that ash plumes rose
to an altitude of 3.7 km (12,100 ft) a.s.l. Analyses of satellite
imagery during 5-12 November revealed almost daily thermal anomalies
and ash plumes that drifted 190 km E during 8-12 November. The Level
of Concern Color Code remained at Orange. Based on information from
the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 14
November an ash plume rose to an altitude of 3.7 km (12,000 ft) a.s.l.
and drifted E.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's

eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 11-17 November, HVO reported that lava flowed SE from

underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless

shield complex through a lava tube system, reaching the ocean at
multiple locations between Waikupanaha and an area 700 m farther to
the W. Thermal anomalies detected by satellite suggested active
surface lava flows. Incandescence was seen on the Pu'u 'O'o crater
floor and intermittently from an East wall vent. The vent in

Halema'uma'u crater continued to produce a diffuse white plume that

drifted W and SW. Incandescence originated from a spattering lava pond
inside the vent cavity. Measurements indicated that the sulfur dioxide
emission rate at the summit remained elevated; 600 tonnes per day was
measured on 16 November. The 2003-2007 average rate was 140 tonnes per
day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KIZIMEN Eastern Kamchatka 55.130°N, 160.32°E; summit elev. 2376 m

KVERT reported that seismicity from Kizimen was slightly above
background levels on 6, 8, and 10 November and at background levels
the other days during 7-13 November. The Level of Concern Color Code
was lowered to Green.

Geologic Summary. Kizimen is an isolated, conical stratovolcano that

is morphologically similar to Mount St. Helens prior to its 1980
eruption. The summit of Kizimen consists of overlapping lava domes,
and blocky lava flows descend the flanks of the volcano, which is the
westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-
m-high Kizimen was formed during four eruptive cycles beginning about
12,000 years ago and lasting 2,000-3,500 years. The largest eruptions
took place about 10,000 and 8300-8400 years ago, and three periods of
longterm lava-dome growth have occurred. The latest eruptive cycle
began about 3,000 years ago with a large explosion and was followed by
lava-dome growth lasting intermittently about 1,000 years. An
explosive eruption about 1,100 years ago produced a lateral blast and
created a 1.0 x 0.7 km wide crater breached to the NE, inside which a
small lava dome (the fourth at Kizimen) has grown. A single explosive
eruption, during 1927-28, has been recorded in historical time.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kizimen Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 6-13 November seismic activity from

Kliuchevskoi was above background levels. Strombolian activity ejected

tephra 300 m above the crater on 5, 7, and 10 November. Satellite
imagery revealed a large daily thermal anomaly at the volcano. The

Level of Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that during 11-17 November gas plumes from Nevado
del Huila were seen on the web camera rising 2.5 km and drifting
downwind. Ash plumes sometimes accompanied the gas emissions on 12,
13, and 15 November. The Alert Level remained at II (Orange; "probable

eruption in term of days or weeks"). Based on analyses of satellite

imagery, the Washington VAAC reported that during 11-16 November
thermal anomalies were seen intermittently through cloud cover.

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),
Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that on 14 November an ash plume from Popocatépetl
rose to an altitude of 7.4 km (24,300 ft) a.s.l. During 14-17
November, steam-and-gas plumes sometimes contained ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 11-14 November ash plumes from Rabaul caldera's Tavurvur cone
rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 75-150 km
NW and W.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 14 November ash plumes from Reventador drifted 10-20 km WNW
and W. An intermittent thermal anomaly was also detected.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 11-13 and 15-17 November produced plumes that
rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted in
multiple directions.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,

is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 16 November small plumes from Sangay, possibly with ash,
drifted WNW. A thermal anomaly was also detected.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 13 November, INSIVUMEH reported that an explosion from Santa
María's Santiaguito lava dome complex produced a plume that drifted
SW. Avalanches descended the SW flank of the dome. Based on analyses
of satellite imagery, the Washington VAAC reported that on 16 November
multiple ash plumes drifted WSW.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 6-13 November seismic activity from
Shiveluch was above background levels, possibly indicating that ash
plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. According to
video camera data, ash plumes rose to an altitude of 4.2 km (13,800
ft) a.s.l. on 5 November and hot avalanches were noted during 10-12
November. Analyses of satellite imagery revealed a large daily thermal
anomaly on the lava dome and ash plumes that drifted 320 km E on 11
November. The Level of Concern Color Code remained at Orange. Based on
information from KEMSD and analyses of satellite imagery, the Tokyo
VAAC reported that on 14 November an eruption produced a plume that

rose to an altitude of 4.9 km (16,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 6-13 November activity from the Soufrière
Hills lava dome continued at a high level. Pyroclastic flows mainly
occurred towards the W down Gages Valley and SW down Gingoes Ghaut.
Good views of the lava dome on 9 and 10 November revealed that recent
lava-dome growth was concentrated on the WSW side, immediately NE of
Chances Peak; intense incandescence and rockfalls were noted at night.
Ash fell across the Montserrat on 11 November, and about 6-8 km NW in
Salem, Old Towne, Olveston, and Woodlands on 12 November. The largest
pyroclastic flow during the reporting period, on 12 November, traveled
WSW, nearly reaching the sea at Kinsale village. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima on 12 and 16 November. Details of possible resulting
emissions were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-

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> SI / USGS Weekly VolcanicActivityReport
>

> NewVolcanosErupting This Week: 2 ~~
Total Active 16
18 November - 24 November 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Galeras, Colombia
| Sarychev Peak, Matua Island

OngoingActivity:

| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)

| Kliuchevskoi, Central Kamchatka (Russia)
| Pacaya, Guatemala

| Popocatépetl, México
| Rabaul, New Britain
| Reventador, Ecuador
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significantactivity.

   The Weekly VolcanicActivityReport is a cooperative
   project between the Smithsonian's Global Volcanism
   Program and the US Geological Survey'sVolcano
   Hazards Program.

  Updated by 2300 UTC every Wednesday, notices of
   volcanicactivityposted on these pages are preliminary
   and subject to change as events are studied in more detail.
   This is not a comprehensive list of all of Earth's
   volcanoes erupting during the week, but rather a summary

of activity at volcanoes that meet criteria discussed in

   detail in the "Criteria and Disclaimers" section. Carefully
   reviewed, detailed reports on various volcanoes are
   published monthly in the Bulletin of the
   Global Volcanism Network.

Note: Many news agencies do not archive the
articles they post on the Internet, and therefore
the links to some sources may not be active.
To obtain information about the cited articles
that are no longer available on the Internet
contact the source.

NewActivity/Unrest:
GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

An explosive eruption from Galeras detected by the seismic network on
20 November prompted INGEOMINAS to raise the Alert Level to I (Red;
"imminent eruption or in progress"). Residents reported five
explosions, sound waves, and incandescence from multiple areas in the
crater. Plume modelling from the Washington VAAC suggested that the
resulting ash plume may have risen as high as 14.3 km (46,900 ft)
a.s.l. and drifted N. Ashfall was reported in areas 10 km E, N, and
NNW. Seismicity increased after the eruption and then gradually
decreased. On 21 November, INGEOMINAS lowered the Alert Level to II
(Orange; "probable eruption in term of days or weeks"). According to
news articles, 900-1,000 people out of about 9,000 ordered to evacuate
went to shelters.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),
Agence France-Presse

Galeras Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that a thermal anomaly on Sarychev Peak was detected by
satellite on 21 November.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 24 November an ash plume from Batu Tara rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 90 km NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, the Buenos Aires VAAC reported that on 23
November a gas plume from Chaitén's lava-dome complex rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted SSE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background

levels on 12, 14, and 16 November; data were not available on the
other days during 13-20 November due to technical reasons. Elevated
seismicity possibly indicated that ash plumes rose to an altitude of 3
km (9,900 ft) a.s.l. Analyses of satellite imagery revealed a daily
thermal anomaly and ash plumes that drifted 130 km E during 12-14 and
17 November. The Level of Concern Color Code remained at Orange. Based
on information from KEMSD, the Tokyo VAAC reported that on 23 November
an eruption produced a plume that rose to an altitude of 4 km (13,000
ft) a.s.l.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 18-24 November, HVO reported that lava flowed SE from beneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the ocean at multiple locations
between Waikupanaha and an area 700 m farther to the W. Thermal

anomalies detected by satellite and visual observations revealed
active surface lava flows at locations on and at the base of the pali,
at the TEB vent, and on the coastal plain. Incandescence was seen on
the Pu'u 'O'o crater floor.

The vent in Halema'uma'u crater continued to produce a white or off-
white plume that drifted mainly SW and dropped small amounts of ash
downwind. Incandescence originated from a circulating and spattering
lava pond that occasionally rose above and drained back below holes in
the vent cavity floor. On 21 November, a sliver of the rim collapsed
and was followed by an explosion that produced a dense brown plume
that dissipated after a few minutes (http://hvo.wr.usgs.gov/kilauea/
update/archive/2009/Nov/HMMvent_21Nov2009_x2speed.mov). Measurements

indicated that the sulfur dioxide emission rate at the summit remained

elevated; 700-1,100 tonnes per day was measured during 18-20 and 23

November. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 13-20 November seismic activity from

Kliuchevskoi was above background levels. Strombolian activity ejected

tephra 200 m above the crater during 13-15 November. On 14 November, a
new lava flow traveled 500 m down the ESE flank. Satellite imagery

revealed a large daily thermal anomaly at the volcano. The Level of
Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 20 and 24 November, INSIVUMEH reported that white and blue plumes
from Pacaya's MacKenney cone rose up to 400 m and drifted SSW.
Multiple lava flows on the S and SW flanks traveled 100-250 m SE and
SW. Incandescence at night was noted.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 18-20 November steam-and-gas plumes from
Popocatépetl sometimes contained ash. A small explosion detected by
the seismic network on 21 November was accompanied by an ash plume
that rose to an altitude of 8.9 km (29,200 ft) a.s.l. The ash plume
drifted E and caused ashfall in Atlixco (23 km SE), Huejotzingo (27 km
NE), and areas in the state of Tlaxcala.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 19 November ash plumes from Rabaul caldera's Tavurvur cone rose to
an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 35-90 km NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

Based on a pilot observation, the Washington VAAC reported that on 20
November an ash plume from Reventador rose to an altitude of 6.1 km
(20,000 ft) a.s.l. A thermal anomaly was detected on satellite
imagery.

Geologic Summary. Reventador is the most frequently active of a chain

of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima on 18 and 23 November produced plumes that rose to
altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted S and E.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 20 November, INSIVUMEH reported that two explosions from Santa
María's Santiaguito lava dome complex produced an ash plume that
drifted SW. Avalanches descended the SW flank of the dome. An
explosion on 24 November produced an ash plume the rose to an altitude
of 3.3 km (10,800 ft) a.s.l. and drifted SE. Ashfall was reported in
areas downwind.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 13-20 November seismic activity from

Shiveluch was above background levels, possibly indicating that ash

plumes rose to an altitude of 5.3 km (17,400 ft) a.s.l. According to
video camera data, fumarolic activity and hot avalanches were noted on
14 and 15 November. Analyses of satellite imagery revealed a large
daily thermal anomaly on the lava dome. The Level of Concern Color
Code remained at Orange. Based on information from KEMSD, the Tokyo
VAAC reported that on 18 November an eruption produced a plume that

rose to an altitude of 5.5 km (18,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 13-20 November activity from the Soufrière
Hills lava dome consisted of ash venting along with semi-continuous
rockfalls and pyroclastic flows that were concentrated on the W flank.
Ashfall occurred across many areas of the island. Views of the lava
dome on 16 November showed that the dome height had decreased because
of collapses and that a deep channel had developed NE of Chances Peak.
Pyroclastic flows in the Gages Valley (W) continued down Spring Ghaut
and Aymer's Ghaut, and spread onto the alluvial fan below St. Georges
Hill. On 19 November, heavy ashfall occurred to the NW between Old
Towne and Brades. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion
from Suwanose-jima on 18 November. Details of possible resulting
emissions were not reported.

Map

Find a Volcano by Eruption Date

Global Volcanism Program — Department of Mineral Sciences — National
Museum of Natural History — Smithsonian Institution

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Dec 3, 2009, 10:55:26 AM12/3/09

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SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: 4 ~~

Total Active 17
25 November-1 December 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Galeras, Colombia

| Gaua, Banks Islands (SW Pacific)

| Karkar, Northeast of New Guinea (SW Pacific)
| Sarychev Peak, Matua Island

OngoingActivity:

| Chaitén, Southern Chile
| Dukono, Halmahera
| Fuego, Guatemala

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Nevado del Huila, Colombia

| Rabaul, New Britain
| Sakura-jima, Kyushu

| Sangay, Ecuador

NewActivity/Unrest:

On 27 November, INGEOMINAS lowered the Alert Level for Galeras to III
(Yellow; "changes in the behavior of volcanic activity"). During the
previous few days, seismicity was low and occasionally punctuated by
signals indicative of minor gas and ash emissions. An overflight on 26
November revealed gas emissions from the interior walls of the main
crater and thermal anomalies with temperatures of 200 degrees Celsius.
During 27 November-1 December, seismicity remained low; signals
indicated gas emissions.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

The Vanuatu Geohazards Observatory reported that a large explosion
from Gaua's Mount Garat on 18 November was followed by high dense ash
plumes. Seismicity increased on 25 October and remained significant
through 24 November. According to news articles, an explosion that
caused ashfall in inhabited areas on 26 November prompted the
evacuation of more than 300 people. The Alert Level was raised to 4,
the second highest level on a scale of 0-5.

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Sources: Vanuatu Geohazards Observatory, Agence France-Presse

Gaua Information from the Global Volcanism Program

KARKAR Northeast of New Guinea (SW Pacific) 4.649°S, 145.964°E; summit
elev. 1839 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

an eruption from Karkar on 25 November produced a plume that rose to
an altitude of 13.7 km (45,000 ft) a.s.l. The report also stated that
ash had merged with a thunderstorm cloud and had become
unidentifiable. Another ash plume identified on 26 November rose to an
altitude of 9.1 km (30,000 ft) a.s.l. Confirmation of ash emissions
was not available from RVO at the time of the posting of this report.

Geologic Summary. Karkar is a 19 x 25 km wide, forest-covered island
that is truncated by two nested summit calderas. The 5.5-km-wide outer
caldera was formed during one or more eruptions, the last of which
occurred 9000 years ago. The eccentric 3.2-km-wide inner caldera was
formed sometime between 1500 and 800 years ago. Parasitic cones are
present on the northern and southern flanks of basaltic-to-andesitic
Karkar volcano; a linear array of small cones extends from the
northern rim of the outer caldera nearly to the coast. Most historical
eruptions, which date back to 1643, have originated from Bagiai cone,
a pyroclastic cone constructed within the steep-walled, 300-m-deep
inner caldera. The floor of the caldera is covered by young, mostly
unvegetated andesitic lava flows.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Karkar Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that a thermal anomaly on Sarychev Peak was detected by

satellite on 25 November. Steam-and-gas emissions were noted on 25,
26, and 29 November.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

Ongoing Activity

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on analyses of satellite imagery, the Buenos Aires VAAC reported
that on 26 November a diffuse plume from Chaitén's lava-dome complex
drifted ENE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 30 November an ash plume from Dukono
at an altitude of 3 km (10,000 ft) a.s.l. was observed on satellite
imagery 75 km E.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 29 November a small plume from Fuego, possibly containing ash,
drifted 10 km SW. A thermal anomaly was also detected. On 30 November
and 1 December, INSIVUMEH reported that explosions produced ash plumes
that rose to altitudes of 4.3-4.7 km (14,100-15,400 ft) a.s.l. and
drifted 8-15 km W and SW. Rumbling noises were noted and incandescent
block avalanches were generated.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background

levels on 23 and 25 November; data were not available on the other
days during 20-27 November due to technical reasons. Elevated

seismicity possibly indicated that ash plumes rose to an altitude of

3.8 km (12,500 ft) a.s.l. Analyses of satellite imagery revealed a
daily thermal anomaly and ash plumes that drifted 120 km E on 23 and
25 November. The Level of Concern Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 25 November-1 December, HVO reported that lava flowed SE from

beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield
complex through a lava tube system, reaching the ocean at multiple

locations between Waikupanaha and an area 700 m farther to the W. A
small bench collapse may have occurred on 27 November. Thermal

anomalies detected by satellite and visual observations revealed

active surface lava flows on the coastal plain. Incandescence was
occasionally seen on the Pu'u 'O'o crater floor.

The vent in Halema'uma'u crater continued to produce a white or off-
white plume that drifted mainly SW and dropped small amounts of ash

downwind. Incandescence originated from a lava pond deep in the vent
cavity floor; the lava pond circulated and spattered during 25-26
November and 1 December. Measurements indicated that the sulfur
dioxide emission rate at the summit remained elevated; 1,000 tonnes
per day were measured on 28 and 30 November. The 2003-2007 average

rate was 140 tonnes per day.

According to a news article on 30 November, Hawaii county was declared
a natural disaster area due to the negative impact that vog from
Halema'uma'u crater has had on croplands and livestock.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO),
Hawaii News Now

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 20-27 November seismic activity from
Kliuchevskoi was above background levels and lava continued to flow
down the ESE flank. Strombolian activity ejected tephra 300 m above
the crater during 21-25 November. Satellite imagery revealed a large

daily thermal anomaly at the volcano. The Level of Concern Color Code
remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that during 25 November-1 December gas plumes from
Nevado del Huila were seen on the web camera rising 8.4 km (27,600 ft)
a.s.l. and drifting downwind. Seismicity included both tremor
indicative of gas emissions and hybrid earthquakes. An overflight on
25 November revealed that the newest lava dome had continued to grow.
Based on pilot observations, the Washington VAAC reported that on 26
November a gas plume, possibly containing ash, rose to an altitude of
7.6 km (25,000 ft) a.s.l. Ash was not identified in satellite imagery,
although low weather clouds were present in the area. A sulfur dioxide
plume was emitted on 30 November at a calculated rate of 3,900 tons
per day. The Alert Level remained at II (Orange; "probable eruption in

term of days or weeks").

Geologic Summary. Nevado del Huila, the highest active volcano in

Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),

Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 20-26 November thick white plumes and gray
ash plumes rose from Rabaul caldera's Tavurvur cone. Strong explosions
produced ash plumes that rose 1.5 km above the summit and showered the
flanks with lava fragments that were incandescent at night. Shock
waves rattled windows in the Kokopo area, about 20 km SE.
Occasionally, incandescence from the summit crater was noted.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima on 26 November and 1 December produced plumes that
rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted SW
and E. Ash was seen in satellite imagery on 26 November.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on a pilot observation, the Washington VAAC reported that on 1
December an ash plume from Sangay rose to an altitude of 7.9 km
(26,000 ft) a.s.l. and drifted W. Ash was not identified in satellite
imagery, although low weather clouds were present in the area. Later
that day, an eruption was reported, but ash was again unidentifiable
in satellite imagery.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 20-27 November seismic activity from

Shiveluch was above background levels, possibly indicating that ash

plumes rose to an altitude of 4.3 km (14,100 ft) a.s.l. Fumarolic
activity was seen using a video camera. Analyses of satellite imagery
revealed a large daily thermal anomaly from the lava dome. The Level

of Concern Color Code remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 20-27 November activity from the Soufrière
Hills lava dome continued at a high level. Activity increased on 21
November and periods of tremor were detected on 23 November. Lava
extrusion during this period shifted from the W side of the lava dome
to the summit region. As a result, abundant pyroclastic flows traveled
NE down Tuitt's Ghaut on 23 November for the first time in several
weeks. On 24 November there was a period of 120 minutes of continuous
pyroclastic flow activity, followed by 90 minutes of semi-continuous
activity. The pyroclastic flows traveled W down Gages Valley and into
Spring Ghaut, and NE down Tuitt's Ghaut and Whites Bottom Ghaut
reaching Tuitt's village. Associated ash plumes rose to an altitude of
6.1 km (20,000 ft) a.s.l. On 26 November, a pyroclastic flow that
descended the Tar River valley was caused by collapse of part of the
old, pre-2009 lava dome. Ashfall occurred in Old Towne and parts of
Olveston. Incandescent material seen in a photograph taken at night on
29 November traveled down the flanks of the lava dome in several
areas. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

The Tokyo VAAC reported that on 26 November an ash plume from Suwanose-
jima was seen by a pilot 65 km S drifting NE at an altitude of 3 km
(10,000 ft) a.s.l.

Raymond Yohros

unread,

Dec 3, 2009, 11:17:58 AM12/3/09

to

On Dec 3, 10:55 am, "leonard7...@gmail.com" <leonard7...@gmail.com>
wrote:

its this for real?

if this is true that could mean that we are
at the edge of a runaway greenhouse effect?

leona...@gmail.com

unread,

Dec 3, 2009, 12:32:18 PM12/3/09

to

•• I do not know how you come to that effect.
The IPCC has been promoting stuff that
is scientifically improbable if not impossible
like "forcing". CO2 only stays in the clouds
until the next rain when it turns into fertilizer.

•• The current volcanic activity averages about
16 from week to week.

•• The current interglacial period (Holocene)
was a period with much vulcanism. Volcanic
blocking the sun has been held responsible
for the "Little Ice Age". One active volcano
from the Holocene is "Chaiten" in the south
of Chile. I believe it is responsible for some
local warming on Antarctica.

Last Post

unread,

Dec 10, 2009, 12:37:31 AM12/10/09

to

SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: 1 ~~

Total Active 15
2 December-8 December 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:
Llaima, Central Chile

Ongoing Activity:

| Ambrym, Vanuatu (SW Pacific)

| Chaitén, Southern Chile
| Colima, México

| Rabaul, New Britain
| Sakura-jima, Kyushu

| San Cristóbal, Nicaragua

NewActivity/Unrest:

AMBRYM Vanuatu (SW Pacific) 16.25°S, 168.12°E; summit elev. 1334 m

On 3 December, a diffuse plume from Ambrym, likely largely composed of
sulfur dioxide, was visible on satellite imagery acquired by the
Moderate Resolution Imaging Spectroradiometer (MODIS) and posted on
NASA's Earth Observatory website.

Geologic Summary. Ambrym, a large basaltic volcano with a 12-km-wide
caldera, is one of the most active volcanoes of the New Hebrides arc.
A thick, almost exclusively pyroclastic sequence, initially dacitic,
then basaltic, overlies lava flows of a pre-caldera shield volcano.
The caldera was formed during a major Plinian eruption with dacitic
pyroclastic flows about 1900 years ago. Post-caldera eruptions,
primarily from Marum and Benbow cones, have partially filled the
caldera floor and produced lava flows that ponded on the caldera floor
or overflowed through gaps in the caldera rim. Post-caldera eruptions
have also formed a series of scoria cones and maars along a fissure
system oriented ENE-WSW. Eruptions have apparently occurred almost
yearly during historical time from cones within the caldera or from
flank vents. However, from 1850 to 1950, reporting was mostly limited
to extra-caldera eruptions that would have affected local populations.

Map

Source: NASA Earth Observatory

Ambrym Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on analyses of satellite imagery, the Buenos Aires VAAC reported

that emissions from Chaitén's lava-dome complex drifted 15 km SE on 8
December.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

COLIMA México 19.514°N, 103.62°W; summit elev. 3850 m

The government of the state of Colima reported that on 1 December a
white plume from the Colima volcano rose 100 m above the crater and
drifted E. On 2 December, incandescent tephra was ejected 50 m above
the crater towards the SE. Later that day, a white plume rose 50 m and
drifted SW.

Geologic Summary. The Colima volcanic complex is the most prominent

volcanic center of the western Mexican Volcanic Belt. It consists of
two southward-younging volcanoes, Nevado de Colima (the 4,320 m high
point of the complex) on the N and the historically active Volcán de
Colima on the S. Volcán de Colima (also known as Volcán Fuego) is a
youthful stratovolcano constructed within a 5-km-wide caldera,
breached to the S, that has been the source of large debris
avalanches. Major slope failures have occurred repeatedly from both
the Nevado and Colima cones, and have produced a thick apron of debris-
avalanche deposits on three sides of the complex. Frequent historical
eruptions date back to the 16th century. Occasional major explosive
eruptions (most recently in 1913) have destroyed the summit and left a
deep, steep-sided crater that was slowly refilled and then overtopped
by lava dome growth.

Map

Source: Gobierno del Estado de Colima

Colima Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that during 5-6 December ash plumes from
Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted
55-85 km NE and SE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 4 December, INSIVUMEH reported that multiple explosions produced

ash plumes that rose to altitudes of 4.2-4.7 km (13,800-15,400 ft)

a.s.l. and drifted 15-18 km W. Ashfall was reported in communities
downwind. Rumbling noises and incandescent block avalanches were also
noted.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background

levels during 27-30 November and 1 December; data were not available
during 2-4 December due to technical problems. Analyses of satellite

imagery revealed a daily thermal anomaly and ash plumes that drifted

165 km E during 29-30 November and 1-2 December. The Level of Concern

Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 2-8 December, HVO reported that lava flowed SE from beneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the ocean at multiple locations

between Waikupanaha and an area 700 m farther to the W. Thermal

anomalies detected by satellite and visual observations revealed

active lava flows on the coastal plain. Incandescence was occasionally
seen from Pu'u 'O'o crater; on 2 December, incandescence originated
from vents on the E wall. The vent in Halema'uma'u crater continued to
produce a white or off-white plume that drifted E, W, and SW, and

dropped small amounts of ash downwind. Incandescence originated from

multiple spattering holes in the deep floor of the vent cavity.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 27 November-4 December seismic activity

from Kliuchevskoi was above background levels and lava continued to
flow down the ESE flank. Strombolian activity ejected tephra 300 m

above the crater. Satellite imagery revealed a large daily thermal

anomaly at the volcano. The Level of Concern Color Code remained at
Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that during 27 November-3 December dense white plumes and

gray ash plumes rose from Rabaul caldera's Tavurvur cone. Strong
explosions produced ash plumes that rose 1.5 km above the summit and
showered the flanks with lava fragments that were incandescent at
night. Shock waves rattled windows in the Kokopo area, about 20 km SE.

Incandescence from the summit crater was occasionally noted. During
2-4 December, ash fell in Rabaul town (3-5 km NW) and other villages
downwind. Based on analyses of satellite imagery, the Darwin VAAC
reported that during 5 and 7-8 December ash plumes rose to an altitude
of 2.4 km (8,000 ft) a.s.l. and drifted 45-55 km E.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 2-8 December produced plumes that rose to
altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted in
multiple directions. On 4 and 8 December, pilots 30-65 km S of
Kagoshima airport reported ash plumes that rose to an altitude of 1.8
km (6,000 ft) a.s.l. and drifted SW and NE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SAN CRISTOBAL Nicaragua 12.702°N, 87.004°W; summit elev. 1745 m

Based on analyses of satellite imagery, the Washington VAAC reported

that on 6 December a gas-and-steam plume from San Cristóbal, possibly
containing ash, drifted SW. The VAAC also noted smoke from local
fires.

Geologic Summary. The San Cristóbal volcanic complex, consisting of
five principal volcanic edifices, forms the NW end of the Marrabios
Range. The symmetrical 1,745-m-high youngest cone, San Cristóbal
itself (also known as El Viejo), is Nicaragua's highest volcano and is
capped by a 500 x 600 m wide crater. El Chonco, with several flank
lava domes, is located 4 km to the west of San Cristóbal; it and the
eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of
Pleistocene age. Volcán Casita contains an elongated summit crater and
lies immediately E of San Cristóbal; Casita was the site of a
catastrophic landslide and lahar in 1998. The Plio-Pleistocene La
Pelona caldera is located at the eastern end of the San Cristóbal
complex. Historical eruptions from San Cristóbal, consisting of small-
to-moderate explosive activity, have been reported since the 16th
century. Some other 16th-century eruptions attributed to Casita
volcano are uncertain and may pertain to other Marrabios Range
volcanoes.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

San Cristóbal Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 27 November-4 December seismic activity

from Shiveluch was above background levels, possibly indicating that

ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. Fumarolic
activity was seen with a video camera. Analyses of satellite imagery
revealed a large daily thermal anomaly from the lava dome and gas-and-
steam plumes, possibly with ash, drifting 70 km E on 27, 28, and 30

November. The Level of Concern Color Code remained at Orange. Based on

information from KEMSD, the Tokyo VAAC reported that on 4 December an
eruption produced a plume that rose to an altitude of 5.8 km (19,000
ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 27 November-4 December activity from the
Soufrière Hills lava dome continued at a high level. Pyroclastic flow
activity was concentrated to the NE and W. The largest pyroclastic
flows traveled NE down Tuitt's Ghaut on 27 November and 2 December,
reaching within 200 m of the sea. Associated ash plumes rose to
altitudes of 4.6-6.1 km (15,000-20,000 ft) a.s.l. Pyroclastic flows
also traveled W down Gages Valley, S down the White River valley and
Gingoes Ghaut, and into the upper reaches of Tyers Ghaut (NW). One
descended the Tar River valley to the E. Rockfalls cascaded directly
from the summit of the lava dome into Tyers Ghaut. Ash venting from
the S part of the lava dome was noted several times. Ashfall
containing accretionary lapilli, reported from Salem, Old Towne, and
parts of Olveston on the evening of 27 November, was associated with a
pyroclastic flow down Tuitt's and White Bottom Ghaut. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion
from Suwanose-jima during 5-6 December. Details of possible resulting
emissions were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-

Map

Uncle Al

unread,

Dec 10, 2009, 10:50:28 AM12/10/09

to

Last Post wrote:
>
> SI / USGS Weekly VolcanicActivityReport
>
> NewVolcanosErupting This Week: 1 ~~
>
> Total Active 15
> 2 December-8 December 2009
>
> Sally Kuhn Sennert - Weekly Report Editor
> http://www.volcano.si.edu/reports/usgs/
>
> NewActivity/Unrest:
> Llaima, Central Chile
>
> Ongoing Activity:
>
> | Ambrym, Vanuatu (SW Pacific)

> | Chait�n, Southern Chile
> | Colima, M�xico

> | San Crist�bal, Nicaragua
> | Shiveluch, Central Kamchatka (Russia)
> | Soufri�re Hills, Montserrat
> | Suwanose-jima, Ryukyu Islands (Japan)

[snip]

Why aren't we disposing of our international, political, and domestic
enemies in their calderas?

Uncle Al had a message in a bottle recovered in the Ryukyu Islands
after 14 years of travel.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm

Last Post

unread,

Dec 17, 2009, 11:58:00 AM12/17/09

to

SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: 1 ~~

Total Active 15
9 December-15 December 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:
| Concepción, Nicaragua
| Galeras, Colombia
| Mayon, Luzon

| Piton de la Fournaise, Reunion Island

| Soufrière Hills, Montserrat

OngoingActivity:

| Chaitén, Southern Chile

| Manam, Northeast of New Guinea (SW Pacific)
| Nevado del Huila, Colombia
| Pacaya, Guatemala

| Rabaul, New Britain
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significantactivity.

      The Weekly VolcanicActivityReport is a cooperative
      project between the Smithsonian's Global Volcanism
      Program and the US Geological Survey'sVolcano
      Hazards Program.

     Updated by 2300 UTC every Wednesday, notices of
      volcanicactivityposted on these pages are preliminary
      and subject to change as events are studied in more detail.
      This is not a comprehensive list of all of Earth's
      volcanoes erupting during the week, but rather a summary

ofactivityat volcanoes that meet criteria discussed in

      detail in the "Criteria and Disclaimers" section. Carefully
      reviewed, detailed reports on various volcanoes are
      published monthly in the Bulletin of the
      Global Volcanism Network.

    Note: Many news agencies do not archive the
    articles they post on the Internet, and therefore
    the links to some sources may not be active.
    To obtain information about the cited articles
    that are no longer available on the Internet
     contact the source.

NewActivity/Unrest:

CONCEPCION Nicaragua 11.538°N, 85.622°W; summit elev. 1700? m

According to a news article, INETER reported that an explosion of ash
and gas from Concepción on 11 December produced a plume that rose 150
m above the crater. Ashfall was reported in three nearby communities.

Geologic Summary. Volcán Concepción is one of Nicaragua's highest
volcanoes and is also one of its most active. The symmetrical volcano
forms the NW half of the dumbbell-shaped island of Ometepe in Lake
Nicaragua. Concepción is connected to neighboring Madera volcano by a
narrow isthmus. N-S-trending fractures cutting across the volcano are
associated with spatter cones, cinder cones, and maars located on the
middle N flank and on the lower S flank down to Lake Nicaragua.
Concepción has had frequent moderate explosive eruptions in the past
century, most of which have originated from a small summit crater.

Map

Source: Reuters

Concepción Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

INGEOMINAS reported that observations of Galeras during an overflight
on 3 December revealed thermal anomalies in the main crater measuring
155 degrees Celsius. During 8-11 December, seismic activity decreased,

although some seismic signals resembled patterns seen prior to

previous eruptions. Sulfur dioxide emissions were low. Seismicity
increased on 12 December; earthquakes M 2.2 and less were detected
within 2 km of the summit and at depths up to 3 km below the summit
during 12-15 December. The Alert Level was raised to II (Orange;

"probable eruption in term of days or weeks").

Geologic Summary. Galeras, a stratovolcano with a large breached

caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

According to news articles, PHIVOLCS reported that on 11 December an
explosion from Mayon was detected by the seismic network. On 14
December, incandescence emanated from the lava dome in the summit
crater and incandescent material traveled as far as 3 km down the S
and SE flanks. At least five minor explosions were detected by the
seismic network. Some local ashfall was reported. The Alert Level was
raised to 3, prompting the order to evacuate about 50,000 people
living within an 8-km radius from the base of the volcano.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Sources: Philippine Daily Inquirer, Inquirer Southern Luzon, The
Manila Times

Mayon Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

OVPDLF reported that on 14 December an eruption from Piton de la
Fournaise was preceded by a seismic crisis and summit deformation. Sub-
parallel fissures along the rim of Dolomieu crater fed lava flows on
the S slope. A third fissure that also produced lava flows opened on
the E flank. The lava stopped flowing during the night, after a
gradual decrease. On 15 December, gas was emitted from the S and SE
fractures and low-intensity tremor was detected.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 4-11 December activity from the Soufrière
Hills lava dome continued at a high level and pyroclastic flow
activity was concentrated on the N side. Pyroclastic flows traveled as
far as 2 km NW into Tyers Ghaut and NE in abundance down Tuitt's
Ghaut, and sometimes Whites Bottom Ghaut, continuing onto Farrell's
plain. A few small pyroclastic flows also descended the Tar River
valley to the E. On 10 December, a large seismic signal was associated
with a relatively large pyroclastic flow in Tyers Ghaut that traveled
3.5 km, stopping just beyond the W end of Lee's village. The event
prompted the National Disaster Preparedness and Response Advisory
Committee (NDPRAC) to raise the Hazard Level to 4, restricting the
hours residents can enter certain pre-designated hazard areas.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

Ongoing Activity

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, the Buenos Aires VAAC reported that a steam-
and-gas plume from Chaitén's lava-dome complex drifted SE on 12
December at altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that during 9-11 December ash plumes from

Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted

90-130 km E and SE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 11, 14, and 15 December, INSIVUMEH reported that explosions from
Fuego produced ash plumes that rose to altitudes of 4.1-4.7 km
(13,500-15,400 ft) a.s.l. and drifted 8-12 km W and SW. Incandescence
from the main crater and rumbling noises were noted. Avalanches
descended the S and W flanks. Based on analyses of satellite imagery,
the Washington VAAC reported that on 12 December a gas-and-ash plume
drifted 20 km W. On 15 December, ashfall was reported in areas SW.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that analyses of satellite imagery revealed a thermal
anomaly from Karymsky during 3 and 6-7 December; ash deposits extended
45 km SE on 6 December. A new lava flow was seen on the S flank on 8
December. Seismic data were seldom available due to technical
problems. The Level of Concern Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 9-15 December, HVO reported that lava flowed SE from beneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the ocean at multiple locations

between Waikupanaha and areas farther to the W. Towards the beginning
of the reporting period, thermal anomalies detected by satellite and
visual observations revealed occasional active lava flows.
Incandescence was seen almost daily from Pu'u 'O'o crater. The vent in
Halema'uma'u crater continued to produce an off-white plume that
drifted predominantly to the SW, dropping small amounts of ash
downwind. Incandescence originated from a few holes in the deep floor
of the vent cavity. On 13 December, lava ponded on the floor, crusted
over, and blocked the holes. Incandescence was again visible the next
night.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 4-11 December seismic activity from

Kliuchevskoi was above background levels and lava continued to flow

down the ESE flank. Strombolian activity ejected tephra 200-300 m
above the crater. Gas-and-steam plumes containing small amounts of ash
rose to an altitude of 6.3 km (20,700 ft) a.s.l. and drifted E during
5-9 December. Satellite imagery revealed a large daily thermal anomaly

at the volcano. The Level of Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 12 December an eruption from Manam produced a plume that rose to an
altitude of 3 km (10,000 ft) a.s.l. and drifted 75 km N.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Manam Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

Based on information from the Bogata MWO, the Washington VAAC reported
that on 10 December an ash plume rose to an altitude of 7 km (23,000
ft) a.s.l. and drifted S. Ash was not identified in satellite imagery
due to meteorological clouds in the area. INGEOMINAS reported that
during 9-15 December seismic signals indicated occasional gas-and-ash
emissions. White and bluish gas plumes seen on the web camera rose 2
km. Overflights revealed that the lava dome continued to grow and emit
gases.

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),

Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 11, 14, and 15 December, INSIVUMEH reported that white and blue
fumarolic plumes from Pacaya's MacKenney cone rose up 100 m and
drifted S. Multiple lava flows on the S flank traveled 25-350 m.
Incandescence from one of the inter-crater cones was noted.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that activity from Rabaul caldera's Tavurvur cone
consisted of a few strong explosions towards the beginning of the 4-10
December reporting period, and emissions of gray ash afterwards.
Diffuse white vapor was emitted during quieter intervals. Ash plumes
rose 1 km above the summit and drifted SE towards Tokua and the Tokua
airport, causing suspension of some flights. Based on analyses of
satellite imagery, the Darwin VAAC reported that on 14 December an ash
plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 35
km SE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 9-15 December produced plumes that rose to
altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted NE, E, SE,
and S. On 14 December, a pilot reported that an ash plume drifted S at

an altitude of 2.7 km (9,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,

is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 11, 14, and 15 December, INSIVUMEH reported that explosions from
Santa María's Santiaguito lava dome complex produced ash plumes that
rose to altitudes of 2.8-3.5 km (9,200-11,500 ft) a.s.l. and drifted W
and SW. Avalanches occasionally descended the SE flank of the dome. On
15 December, explosions generated pyroclastic flows that descended the
E and SW flanks.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 4-11 December seismic activity from
Shiveluch was above background levels, possibly indicating ash plumes
rising to an altitude of 5.5 km (18,000 ft) a.s.l. Fumarolic activity

was seen with a video camera. Analyses of satellite imagery revealed a

large daily thermal anomaly from the lava dome and an ash plume
drifting 85 km SE on 6 December. The Level of Concern Color Code

remained at Orange. Based on information from KEMSD, the Tokyo VAAC

reported that on 13 December an eruption produced a plume that rose to

an altitude of 5.8 km (19,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported eruptions from
Suwanose-jima on 14 and 15 December. Plumes rose to altitudes of
1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted E.

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Dec 17, 2009, 12:15:02 PM12/17/09

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SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: 5 ~~

Total Active 20
9 December-16 December 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Concepción, Nicaragua
| Galeras, Colombia
| Mayon, Luzon

| Piton de la Fournaise, Reunion Island

| Soufrière Hills, Montserrat

Ongoing Activity:

| Chaitén, Southern Chile

| Manam, Northeast of New Guinea (SW Pacific)
| Nevado del Huila, Colombia
| Pacaya, Guatemala

| Rabaul, New Britain
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significantactivity.

      The Weekly VolcanicActivityReport is a cooperative
      project between the Smithsonian's Global Volcanism
      Program and the US Geological Survey'sVolcano
      Hazards Program.

     Updated by 2300 UTC every Wednesday, notices of
      volcanicactivityposted on these pages are preliminary
      and subject to change as events are studied in more detail.
      This is not a comprehensive list of all of Earth's
      volcanoes erupting during the week, but rather a summary
      of activity at volcanoes that meet criteria discussed in
      detail in the "Criteria and Disclaimers" section. Carefully
      reviewed, detailed reports on various volcanoes are
      published monthly in the Bulletin of the
      Global Volcanism Network.

    Note: Many news agencies do not archive the
    articles they post on the Internet, and therefore
    the links to some sources may not be active.
    To obtain information about the cited articles
    that are no longer available on the Internet
     contact the source.

NewActivity/Unrest:

CONCEPCION Nicaragua 11.538°N, 85.622°W; summit elev. 1700? m

According to a news article, INETER reported that an explosion of ash
and gas from Concepción on 11 December produced a plume that rose 150
m above the crater. Ashfall was reported in three nearby communities.

Geologic Summary. Volcán Concepción is one of Nicaragua's highest
volcanoes and is also one of its most active. The symmetrical volcano
forms the NW half of the dumbbell-shaped island of Ometepe in Lake
Nicaragua. Concepción is connected to neighboring Madera volcano by a
narrow isthmus. N-S-trending fractures cutting across the volcano are
associated with spatter cones, cinder cones, and maars located on the
middle N flank and on the lower S flank down to Lake Nicaragua.
Concepción has had frequent moderate explosive eruptions in the past
century, most of which have originated from a small summit crater.

Map

Source: Reuters

Concepción Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

INGEOMINAS reported that observations of Galeras during an overflight

on 3 December revealed thermal anomalies in the main crater measuring

155 degrees Celsius. During 8-11 December, seismic activity decreased,

although some seismic signals resembled patterns seen prior to

previous eruptions. Sulfur dioxide emissions were low. Seismicity
increased on 12 December; earthquakes M 2.2 and less were detected
within 2 km of the summit and at depths up to 3 km below the summit

during 12-15 December. The Alert Level was raised to II (Orange;

"probable eruption in term of days or weeks").

Geologic Summary. Galeras, a stratovolcano with a large breached

caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

According to news articles, PHIVOLCS reported that on 11 December an

explosion from Mayon was detected by the seismic network. On 14
December, incandescence emanated from the lava dome in the summit
crater and incandescent material traveled as far as 3 km down the S
and SE flanks. At least five minor explosions were detected by the
seismic network. Some local ashfall was reported. The Alert Level was
raised to 3, prompting the order to evacuate about 50,000 people
living within an 8-km radius from the base of the volcano.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises

to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Sources: Philippine Daily Inquirer, Inquirer Southern Luzon, The
Manila Times

Mayon Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

OVPDLF reported that on 14 December an eruption from Piton de la

Fournaise was preceded by a seismic crisis and summit deformation. Sub-
parallel fissures along the rim of Dolomieu crater fed lava flows on
the S slope. A third fissure that also produced lava flows opened on
the E flank. The lava stopped flowing during the night, after a
gradual decrease. On 15 December, gas was emitted from the S and SE
fractures and low-intensity tremor was detected.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the

island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 4-11 December activity from the Soufrière

Hills lava dome continued at a high level and pyroclastic flow
activity was concentrated on the N side. Pyroclastic flows traveled as
far as 2 km NW into Tyers Ghaut and NE in abundance down Tuitt's
Ghaut, and sometimes Whites Bottom Ghaut, continuing onto Farrell's
plain. A few small pyroclastic flows also descended the Tar River
valley to the E. On 10 December, a large seismic signal was associated
with a relatively large pyroclastic flow in Tyers Ghaut that traveled
3.5 km, stopping just beyond the W end of Lee's village. The event
prompted the National Disaster Preparedness and Response Advisory
Committee (NDPRAC) to raise the Hazard Level to 4, restricting the
hours residents can enter certain pre-designated hazard areas.

Geologic Summary. The complex dominantly andesitic Soufrière Hills

volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

Ongoing Activity

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, the Buenos Aires VAAC reported that a steam-

and-gas plume from Chaitén's lava-dome complex drifted SE on 12
December at altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l.

Geologic Summary. Chaitén is a small, glacier-free caldera with a

Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that during 9-11 December ash plumes from

Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted

90-130 km E and SE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 11, 14, and 15 December, INSIVUMEH reported that explosions from

Fuego produced ash plumes that rose to altitudes of 4.1-4.7 km
(13,500-15,400 ft) a.s.l. and drifted 8-12 km W and SW. Incandescence
from the main crater and rumbling noises were noted. Avalanches
descended the S and W flanks. Based on analyses of satellite imagery,
the Washington VAAC reported that on 12 December a gas-and-ash plume
drifted 20 km W. On 15 December, ashfall was reported in areas SW.

Geologic Summary. Volcán Fuego, one of Central America's most active

volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that analyses of satellite imagery revealed a thermal

anomaly from Karymsky during 3 and 6-7 December; ash deposits extended
45 km SE on 6 December. A new lava flow was seen on the S flank on 8
December. Seismic data were seldom available due to technical

problems. The Level of Concern Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 9-15 December, HVO reported that lava flowed SE from beneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the ocean at multiple locations

between Waikupanaha and areas farther to the W. Towards the beginning
of the reporting period, thermal anomalies detected by satellite and
visual observations revealed occasional active lava flows.
Incandescence was seen almost daily from Pu'u 'O'o crater. The vent in
Halema'uma'u crater continued to produce an off-white plume that
drifted predominantly to the SW, dropping small amounts of ash
downwind. Incandescence originated from a few holes in the deep floor
of the vent cavity. On 13 December, lava ponded on the floor, crusted
over, and blocked the holes. Incandescence was again visible the next
night.

Geologic Summary. Kilauea, one of five coalescing volcanoes that

comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 4-11 December seismic activity from

Kliuchevskoi was above background levels and lava continued to flow

down the ESE flank. Strombolian activity ejected tephra 200-300 m
above the crater. Gas-and-steam plumes containing small amounts of ash
rose to an altitude of 6.3 km (20,700 ft) a.s.l. and drifted E during

5-9 December. Satellite imagery revealed a large daily thermal anomaly

at the volcano. The Level of Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 12 December an eruption from Manam produced a plume that rose to an
altitude of 3 km (10,000 ft) a.s.l. and drifted 75 km N.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Manam Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

Based on information from the Bogata MWO, the Washington VAAC reported
that on 10 December an ash plume rose to an altitude of 7 km (23,000
ft) a.s.l. and drifted S. Ash was not identified in satellite imagery
due to meteorological clouds in the area. INGEOMINAS reported that
during 9-15 December seismic signals indicated occasional gas-and-ash
emissions. White and bluish gas plumes seen on the web camera rose 2
km. Overflights revealed that the lava dome continued to grow and emit
gases.

Geologic Summary. Nevado del Huila, the highest active volcano in

Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),

Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 11, 14, and 15 December, INSIVUMEH reported that white and blue

fumarolic plumes from Pacaya's MacKenney cone rose up 100 m and
drifted S. Multiple lava flows on the S flank traveled 25-350 m.

Incandescence from one of the inter-crater cones was noted.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that activity from Rabaul caldera's Tavurvur cone

consisted of a few strong explosions towards the beginning of the 4-10
December reporting period, and emissions of gray ash afterwards.
Diffuse white vapor was emitted during quieter intervals. Ash plumes
rose 1 km above the summit and drifted SE towards Tokua and the Tokua
airport, causing suspension of some flights. Based on analyses of
satellite imagery, the Darwin VAAC reported that on 14 December an ash

plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 35
km SE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 9-15 December produced plumes that rose to
altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted NE, E, SE,

and S. On 14 December, a pilot reported that an ash plume drifted S at

an altitude of 2.7 km (9,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,

is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 11, 14, and 15 December, INSIVUMEH reported that explosions from

Santa María's Santiaguito lava dome complex produced ash plumes that
rose to altitudes of 2.8-3.5 km (9,200-11,500 ft) a.s.l. and drifted W
and SW. Avalanches occasionally descended the SE flank of the dome. On
15 December, explosions generated pyroclastic flows that descended the
E and SW flanks.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is

one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 4-11 December seismic activity from
Shiveluch was above background levels, possibly indicating ash plumes
rising to an altitude of 5.5 km (18,000 ft) a.s.l. Fumarolic activity

was seen with a video camera. Analyses of satellite imagery revealed a

large daily thermal anomaly from the lava dome and an ash plume

drifting 85 km SE on 6 December. The Level of Concern Color Code

remained at Orange. Based on information from KEMSD, the Tokyo VAAC

reported that on 13 December an eruption produced a plume that rose to

an altitude of 5.8 km (19,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported eruptions from

Suwanose-jima on 14 and 15 December. Plumes rose to altitudes of

1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted E.

Last Post

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Dec 17, 2009, 12:32:30 PM12/17/09

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NewVolcanosErupting This Week: 5 ~~

Total Active 21

OngoingActivity:

NewActivity/Unrest:

Map

Source: Reuters

Map

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit lev.
2632 m

Map

dome ...

leona...@gmail.com

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Dec 24, 2009, 12:55:26 AM12/24/09

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SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: 5

Total Active 14
16 December-22 December 2009

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Bezymianny, Central Kamchatka (Russia)
| Cleveland, Chuginadak Island

| Gaua, Banks Islands (SW Pacific)

| Mayon, Luzon
| San Cristóbal, Nicaragua

OngoingActivity:

| Chaitén, Southern Chile

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Sakura-jima, Kyushu
| Sangay, Ecuador

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significantactivity.

        The Weekly VolcanicActivityReport is a cooperative
        project between the Smithsonian's Global Volcanism
        Program and the US Geological Survey'sVolcano
        Hazards Program.

       Updated by 2300 UTC every Wednesday, notices of
        volcanicactivityposted on these pages are preliminary
        and subject to change as events are studied in more detail.

This is not a comprehensivelistof all of Earth's

        volcanoes erupting during the week, but rather a summary
        ofactivityat volcanoes that meet criteria discussed in
        detail in the "Criteria and Disclaimers" section. Carefully
        reviewed, detailed reports on various volcanoes are
        published monthly in the Bulletin of the
        Global Volcanism Network.

      Note: Many news agencies do not archive the
      articles they post on the Internet, and therefore
      the links to some sources may not be active.
      To obtain information about the cited articles
      that are no longer available on the Internet
       contact the source.

NewActivity/Unrest:

BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit
elev. 2882 m

KVERT reported that seismic activity from Bezymianny increased on 8
December. After a significant thermal anomaly was detected in
satellite imagery on 17 December, the Level of Concern Color Code was
raised to Red. A few hours later a large explosive eruption produced
ash plumes that were seen drifting as far as 350 km W and NW in
satellite imagery. Ash plumes likely rose to altitudes greater than 10
km (32,800 ft) a.s.l.; clouds in the area prevented visual
observations. Ashfall up to 3 mm thick was noted in Kozyrevsk, 45 km
W, and other surrounding villages. The Level of Concern Color Code was
lowered to Orange after seismic activity significantly decreased. On
18 December another large thermal anomaly was seen over the volcano
and on the SE flank. Gas-and-steam activity was also noted. During
19-20 December, a thermal anomaly continued to be detected in
satellite imagery. KVERT lowered the Level of Concern Color Code to
Yellow on 21 December.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny
volcano had been considered extinct. Three periods of intensified
activity have occurred during the past 3,000 years. The latest period,
which was preceded by a 1,000-year quiescence, began with the dramatic
1955-56 eruption. That eruption, similar to the 1980 event at Mount
St. Helens, produced a large horseshoe-shaped crater that was formed
by collapse of the summit and an associated lateral blast. Subsequent
episodic but ongoing lava-dome growth, accompanied by intermittent
explosive activity and pyroclastic flows, has largely filled the 1956
crater.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bezymianny Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

On 18 December, AVO reported that a diffuse ash plume emitted from
Cleveland on 12 December was retrospectively detected in satellite
imagery. No other activity was noted.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

On 14 December, Vanuatu Geohazards Observatory reported that activity
from Gaua during the previous month was characterized by continuous
ash emissions accompanied by periodic steam emissions. Ashfall was
reported in the W part of the island. Satellite imagery revealed that
periods of significant gas emissions were more frequent than during
November. Ash emissions during 14-18 December were thicker and darker,
and possibly represented a new eruptive phase. Ash plumes continued to
drift W and produce ashfall. The Vanuatu Volcanic Alert Level remained
at 2 (on a scale of 0-4).

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Vanuatu Geohazards Observatory

Gaua Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

PHIVOLCS reported that during 14-19 December sulfur dioxide emissions
from Mayon fluctuated between 750 and 2,034 tonnes per day. During
15-16 December, detached fragments from lava accumulating in the
summit crater traveled as far as 4 km down the SE-flank Bonga-Buyuan
gully, and lava flows traveled 700-800 m. Occasionally detached lava
fragments produced small pyroclastic surges down the SW flank that
generated light ashfall 13 km S and W in Camalig and Guinobatan,
respectively. Steam plumes rose 200 m above the crater rim and drifted
SW and WSW. During 17-20 December the seismic network detected 66
explosion-type signals; only 23 events were seen during periods of
good visibility. These explosions produced dark gray to dark brown ash
plumes that rose 500-2,000 m above the crater rim and drifted SW.
Harmonic tremor was detected by the seismic network. Brownish-colored
steam and intensified incandescence at night were noted.

On 20 December lava flows had advanced 4.5 km from the crater.
PHIVOLCS raised the Alert Level to 4 (on a scale of 0-5) and
recommended that the Extended Danger Zone (EDZ) encompass an area 8 km
S from the summit and 7 km N from the summit. During 20-22 December
the rate and intensity of seismic signals dramatically increased. The
sulfur dioxide emission rate also increased; 6,089-6,529 tonnes per
day was measured. Booming and rumbling sounds, and intensified crater
incandescence, were noted. Lava fountains rose 200 m above the crater
and lava flowed as far as 5 km down the Bonga-Buyuan, Miisi, and
Lidong gullies.

According to news articles, more than 47,000 people from 30 villages
were in evacuation centers across Albay province. About 3,000-6,000
residents had not evacuated.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Sources: Philippine Institute of Volcanology and Seismology
(PHIVOLCS), Inquirer Southern Luzon and Associated Press, Associated
Press

Mayon Information from the Global Volcanism Program

SAN CRISTOBAL Nicaragua 12.702°N, 87.004°W; summit elev. 1745 m

Based on METAR weather reports, the Washington VAAC reported that on
22 December a gas-and-steam plume that rose from San Cristóbal
possibly contained ash.

Geologic Summary. The San Cristóbal volcanic complex, consisting of
five principal volcanic edifices, forms the NW end of the Marrabios
Range. The symmetrical 1,745-m-high youngest cone, San Cristóbal
itself (also known as El Viejo), is Nicaragua's highest volcano and is
capped by a 500 x 600 m wide crater. El Chonco, with several flank
lava domes, is located 4 km to the west of San Cristóbal; it and the
eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of
Pleistocene age. Volcán Casita contains an elongated summit crater and
lies immediately E of San Cristóbal; Casita was the site of a
catastrophic landslide and lahar in 1998. The Plio-Pleistocene La
Pelona caldera is located at the eastern end of the San Cristóbal
complex. Historical eruptions from San Cristóbal, consisting of small-
to-moderate explosive activity, have been reported since the 16th
century. Some other 16th-century eruptions attributed to Casita
volcano are uncertain and may pertain to other Marrabios Range
volcanoes.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

San Cristóbal Information from the Global Volcanism Program

Ongoing Activity

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 1-15 December Chaitén's lava-dome
complex produced steam, gas, and ash plumes that rose 2 km above the
lava domes. On 7 December emissions originated from the N and S areas
of the complex. Block-and-ash flows were noted the next day. The Alert
Level remained at Red. Based on web camera views and SIGMET notices,
the Buenos Aires VAAC reported that on 18 December an ash plume
drifted SSE at altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 11-13 and 17 December a thermal anomaly
over Karymsky was detected in satellite imagery. Seismic activity was
above background levels on 12 and 13 December; data were not available
during 11-21 December due to technical problems. The Level of Concern

Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 16-22 December, HVO reported that lava flowed SE from beneath

Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex

through a lava tube system, reaching the ocean at Waikupanaha.
Incandescence was seen almost daily coming from Pu'u 'O'o crater. The

vent in Halema'uma'u crater continued to produce an off-white plume

that drifted E and SW, dropping small amounts of ash downwind.

Incandescence originated from a few holes in the deep floor of the

vent cavity. Occasionally, lava ponded on the floor of the cavity.
Spatter originated from a small spatter cone on the E side of the vent
cavity floor. Spatter from the opening frequently fed small lava flows
that traveled down the flank of the cone. The sulfur dioxide emission
rate at the summit remained elevated; 600 tonnes per day were measured
on 18 December. The 2003-2007 average rate was 140 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 11-21 December seismic activity from
Kliuchevskoi was above background levels. Satellite imagery revealed a

large daily thermal anomaly at the volcano. The Level of Concern Color
Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during
16-17 and 20-22 December explosions from Sakura-jima produced plumes
that rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and
drifted E, SE, and S. On 19 and 22 December, pilots reported that ash
plumes rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on pilot observations, the Washington VAAC reported that on 18
and 21 December ash plumes from Sangay rose to an altitude of 7.9 km
(26,000 ft) a.s.l. and drifted W. Ash was not identified in satellite
imagery, although weather clouds were present in the area. Thermal
anomalies were occasionally detected in the satellite imagery.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 11-21 December seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 5.5 km (18,000 ft) a.s.l. Analyses of

satellite imagery revealed a large daily thermal anomaly from the lava

dome. The Level of Concern Color Code remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 11-19 December activity from the Soufrière
Hills lava dome continued at a high level. Night-time incandescence
and observations with a high resolution thermal camera showed that
activity was concentrated on the NW flank. Pyroclastic flows and semi-
continuous rockfalls traveled down the NE, N, and NW flanks,
channelling NE directly into Whites Ghaut and continuing into Whites
Bottom Ghaut. Pyroclastic flows also traveled as far as 2 km NW down
Tyers Ghaut multiple times a day, occasionally as far as 2 km W down
Gages valley, and rarely E down Tar River valley. Fresh deposits from
small pyroclastic flows moving S were seen at the head of the White
River and Gingoes Ghaut. On 19 December heavy ashfall occurred in
several areas in NW Montserrat. The Hazard Level remained at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash

eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported eruptions from

Suwanose-jima during 17-20 and 22 December. A plume rose to an
altitude of 1.5 km (5,000 ft) a.s.l. on 22 December.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

Last Post

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Jan 7, 2010, 11:47:44 AM1/7/10

to

SI / USGS Weekly VolcanicActivityReport

NewVolcanosErupting This Week: 7

Total Active 20
30 December-5 January 2010

             Sally Kuhn Sennert - Weekly Report Editor
            http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Galeras, Colombia
| Mayon, Luzon
| Nyamuragira, Democratic Republic of Congo

| Piton de la Fournaise, Reunion Island

| Rinjani, Lombok Island (Indonesia)
| Tungurahua, Ecuador
| Turrialba, Costa Rica

Ongoing Activity:

| Barren Island, Andaman Is

| Chaitén, Southern Chile
| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Nevado del Huila, Colombia

| Rabaul, New Britain
| Sakura-jima, Kyushu

| Sangay, Ecuador
| Santa María, Guatemala

New Activity/Unrest

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

An explosive eruption from Galeras detected by the seismic network on
2 January prompted INGEOMINAS to raise the Alert Level to I (Red;
"imminent eruption or in progress"). An ash plume rose to an altitude
of 12 km (39,400 ft) a.s.l. and drifted W and NW. Ashfall was reported
in areas downwind, as far away as 110 km W. Ejected incandescent
blocks fell onto the flanks 3.2-3.5 km away from the summit and
ignited fires. An overflight on 3 January revealed diffuse gas plumes
from the main crater. Fires started the previous day continued to burn
on the N flank. The Alert Level was lowered to II (Orange; "probable

eruption in term of days or weeks").

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

PHIVOLCS reported declining activity at Mayon from 28 December to 2
January. Steam plumes were emitted from the crater, but ash plumes
were last seen on 29 December. In addition, the majority of the
seismic signals originated from rockfalls and detached lava fragments
rolling down the flanks from advancing lava flows. Sulfur dioxide
emissions also decreased from close to 9,000 tonnes per day to about
2,600 tonnes per day. PHIVOLCS lowered the Alert Level from 4 to 3,
and reminded the public that no human activity should occur within the
6-km radius Permanent Danger Zone (PDZ) around the volcano and the 7-
km Extended Danger Zone (EDZ) on the SE flank. During 2-5 January,
seismic activity indicated rockfall events related to the detachment
of lava fragments at the upper slopes. Cloud cover at the summit
prevented observations of steam plumes. Incandescence from the crater
at night was noted.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Mayon Information from the Global Volcanism Program

NYAMURAGIRA Democratic Republic of Congo 1.408°S, 29.20°E; summit
elev. 3058 m

According to news articles, Nyamuragira erupted on 2 January from a
fissure on the SE flank. Park rangers reported hearing a loud
explosion in the early morning before seeing flowing lava. By 3
January, the lava flow had traveled 4.6 km, was 15 m wide, and had
burned about 10 hectares of forest in a non-populated area of the
Virunga National Park.

Geologic Summary. Africa's most active volcano, Nyamuragira (Also
spelled Nyamulagira) is a massive basaltic shield volcano N of Lake
Kivu and NW of Nyiragongo volcano. Lava flows from Nyamuragira cover
1,500 sq km of the East African Rift. The 3058-m-high summit is
truncated by a small 2 x 2.3 km summit caldera that has walls up to
about 100 m high. About 40 historical eruptions have occurred since
the mid-19th century within the summit caldera and from numerous
fissures and cinder cones on the volcano's flanks. A lava lake in the
summit crater, active since at least 1921, drained in 1938. Twentieth-
century flank lava flows extend more than 30 km from the summit,
reaching as far as Lake Kivu.

Map

Sources: CNN, Agence France-Presse, UN News Centre, United Nations
Organization Mission in the Democratic Republic of the Congo (MONUC)

Nyamuragira Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

OVPDLF reported that a seismic crisis at Piton de la Fournaise on 29
December was characterized by numerous earthquakes in the area W and
NW of Dolomieu crater (max M 3), at depths of 1.1-2.2 km below the
summit. Deformation was also detected. On 31 December, OVPDLF reported
decreased seismicity and fewer landslides within Dolomieu crater on 30
and 31 December. On 2 January, an eruption from a fissure near the top
of the W crater rim, preceded by a seismic crisis, produced lava
fountains a few tens of meters high and lava flows in Dolomieu crater.
Large landslides in Bory crater (W) along with the fissure eruption
generated ash and gas plumes that rose above Piton de la Fournaise.
During 2-3 January, seismicity and the number of landslides decreased.
As of 4 January, the lava flows covered about 80 percent of the crater
floor. Lava fountaining was still visible.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

RINJANI Lombok Island (Indonesia) 8.42°S, 116.47°E; summit elev. 3726
m

Based on a pilot report, the Darwin VAAC reported that on 2 January an
ash plume from Rinjani rose to an unspecified altitude. The plume was
not identified in satellite imagery; however a meteorological cloud
was present in the area.

Geologic Summary. Rinjani volcano on the island of Lombok rises to
3,726 m, second in height among Indonesian volcanoes only to Sumatra's
Kerinci volcano. Rinjani has a steep-sided conical profile when viewed
from the E, but the W side of the compound volcano is truncated by the
6 x 8.5 km, oval-shaped Segara Anak caldera. The western half of the
caldera contains a 230-m-deep lake whose crescentic form results from
growth of the post-caldera cone Barujari at the E end of the caldera.
Historical eruptions at Rinjani dating back to 1847 have been
restricted to Barujari cone and consist of moderate explosive activity
and occasional lava flows that have entered Segara Anak lake.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rinjani Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported steam emissions from Tungurahua during 30 December-3
January. On 1 January, an ash plume rose to an altitude of 5.9 km
(19,500 ft) a.s.l. and drifted NW. Slight ashfall was reported the
next day in Manzano, 8 km SW. Roaring noises and incandescence from
the crater were also reported. On 3 and 4 January, incandescent blocks
were ejected from the crater. Based on information from the Guayaquil
MWO and SIGMET notices, the Washington VAAC reported that ash plumes
rose to altitudes of 6.7-9.1 km (22,000-30,000 ft) a.s.l. and drifted
W. Thermal anomalies were detected in satellite imagery. On 4 January,
ashfall was reported in areas to the W and SW.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of

Baños on the N side of the volcano.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),

Volcanic Ash Advisory Center (VAAC)

Tungurahua Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

On 5 January, OVSICORI-UNA reported that an eruption from Turrialba
produced ashfall in local areas, particularly in areas to the SW,
including near Irazú volcano (11 km SW). According to news articles,
about 20 people evacuated the area.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Sources: Observatorio Vulcanológico y Sismológico de Costa Rica-
Universidad Nacional (OVSICORI-UNA), Reuters

Turrialba Information from the Global Volcanism Program

Ongoing Activity

BARREN ISLAND Andaman Is 12.278°N, 93.858°E; summit elev. 354 m

Based on a pilot report, the Darwin VAAC reported that on 3 January a
plume from Barren Island rose to an altitude of 1.5 km (5,000 ft)
a.s.l. The plume was not identified in satellite imagery; however a
meteorological cloud was present in the area.

Geologic Summary. Barren Island, a possession of India in the Andaman
Sea about 135 km NE of Port Blair in the Andaman Islands, is the only
historically active volcano along the N-S-trending volcanic arc
extending between Sumatra and Burma (Myanmar). The 354-m-high island
is the emergent summit of volcano that rises from a depth of about
2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-
km-wide caldera with walls 250-350 m high. The caldera, which is open
to the sea on the W, was created during a major explosive eruption in
the late Pleistocene that produced pyroclastic-flow and -surge
deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course
of historical eruptions. Lava flows fill much of the caldera floor and
have reached the sea along the western coast during historical
eruptions.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Barren Island Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, the Buenos Aires VAAC reported that a plume
from Chaitén's lava-dome complex drifted SE on 30 December at an
altitude of 2.1 km (7,000 ft) a.s.l.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that a thermal anomaly over Karymsky was detected in
satellite imagery during 24-26 and 29-30 December. Gas-and-steam
bursts were seen by volcanologists on 28 December. The Level of

Concern Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 30 December-3 January, HVO reported that lava flowed SE from

beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield
complex through a lava tube system, reaching the ocean at Waikupanaha.

Lava was not seen entering the ocean on 4 and 5 January. Thermal
anomalies detected by satellite and occasional visual observations
revealed active lava flows on the pali. Incandescence was seen almost
daily coming from Pu'u 'O'o crater. During an overflight of Pu'u 'O'o
crater on 29 December, geologists saw that a part of the high point of
the W rim had collapsed, and a new gas vent had opened up at base of
the N wall.

The vent in Halema'uma'u crater continued to produce a plume that
drifted NE and NW, dropping small amounts of ash, and occasionally
fresh spatter, downwind. Incandescence originated from an active and
sometimes sloshing lava surface within an opening on the deep floor of
the vent cavity.

Geologic Summary. Kilauea, one of five coalescing volcanoes that

comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 24-31 December seismic activity from

Kliuchevskoi was above background levels and lava continued to flow

down the ESE flank. Strombolian activity ejected material 500 m above
the crater. Satellite imagery revealed a large daily thermal anomaly

at the volcano. The Level of Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

Based on web camera views, INGEOMINAS reported that during 23-29
December a continuous white plume from Nevado del Huila rose 1 km. The
output of sulfur dioxide was less than during the previous months of
October and November. Seismicity and the rate of lava extrusion had
also decreased during the previous weeks. On 5 January, INGEOMINAS
lowered the Alert Level to III (Yellow; "changes in the behavior of
volcanic activity").

Geologic Summary. Nevado del Huila, the highest active volcano in

Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Huila Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that activity from Rabaul caldera's Tavurvur cone was at
a low level during 21-31 December; no emission from the crater was
observed on most days. White steam plumes accompanied by blue plumes
were occasionally emitted. On 23 December, ash emissions rose less
than 200 m above the cone. Based on analyses of satellite imagery, the
Darwin VAAC reported that on 31 December an ash plume rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted less than 30 km SE.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 30
December-5 January multiple explosions from Sakura-jima often produced
plumes that rose to altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l.
and drifted NE, E, SE, and S. During 31 December-4 January pilots
reported that ash plumes rose to altitudes of 2.4-5.5 km (8,000-18,000
ft) a.s.l. and drifted SE and E.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that during 2-4 January thermal anomalies
from Sangay were seen in satellite imagery. On 2 January, a pilot saw
an ash plume drifting NW at an altitude of 7 km (23,000 ft) a.s.l. An
ash plume was also reported by a pilot the next day.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 30 December and 5 January, INSIVUMEH reported that explosions from
Santa María's Santiaguito lava dome complex produced ash plumes that
rose to altitudes of 3-3.4 km (10,000-11,200 ft) a.s.l. and drifted W
and SW. The Washington VAAC reported that ash plumes seen on satellite
imagery drifted more than 30 km WSW. Avalanches occasionally descended

the SW flank of the dome.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is

one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 24-31 December seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 4.9 km (16,000 ft) a.s.l. Fumarolic activity
was occasionally seen when the weather was clear. Analyses of

satellite imagery revealed a large daily thermal anomaly from the lava

dome and an ash plume that drifted 15 km W on 28 December. The Level

of Concern Color Code remained at Orange. Based on information from

KEMSD and KVERT, the Tokyo VAAC reported that during 30 December-3
January eruptions produced plumes that rose to altitudes of 4.3-7.6 km
(14,000-25,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 24-31 December activity from the Soufrière
Hills lava dome continued at a high level. Cycles of increased
activity associated with vigorous ash venting and pyroclastic flows
occurred every six to eight hours. Audible rockfalls, roaring, and
occasional thunder were noted during the most intense events. Frequent
pyroclastic flows traveled N down Whites Ghaut, Farrells plain, and
Tyers Ghaut. Pyroclastic flows also traveled W down Gages Valley into
Spring Ghaut, and occasionally to the S in Gingoes Ghaut. On 29
December several pyroclastic flows traveled 2.5 km, reaching Dyers
village. A comparison of photographs from 30 December and 2 January
revealed that the lava dome morphology had changed rapidly, with a
significant addition of lava on the N side. The additional area of
growth was approximately 60 m high and 100 m wide. The Hazard Level
remained at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 30 December-2 January and 4-5 January. Plumes
rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. on 2 and 4
January, and drifted NE and E on 4 January.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

Last Post

unread,

Jan 14, 2010, 9:02:05 PM1/14/10

to

SI / USGS Weekly VolcanicActivityReport

6 January-12 January 2010
NewVolcanosErupting This Week: 6

Total Active 21

              Sally Kuhn Sennert - Weekly Report Editor
             http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Mayon, Luzon

| Nyamuragira,
| Democratic Republic of Congo
| Piton de la Fournaise, Reunion Island

| Tungurahua, Ecuador
| Turrialba, Costa Rica

Ongoing Activity:

| Barren Island, Andaman Is
| Chaitén, Southern Chile

| Fuego, Guatemala

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Pacaya, Guatemala
| Popocatépetl, México
| Rabaul, New Britain

| Redoubt, Southwestern Alaska
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significantactivity.

          The Weekly VolcanicActivityReport is a cooperative
          project between the Smithsonian's Global Volcanism
          Program and the US Geological Survey'sVolcano
          Hazards Program.

Updated by 2300 UTC every Wednesday, notices of

volcanicactivity posted on these pages are preliminary

          and subject to change as events are studied in more detail.
          This is not a comprehensivelistof all of Earth's
          volcanoes erupting during the week, but rather a summary
          ofactivityat volcanoes that meet criteria discussed in
          detail in the "Criteria and Disclaimers" section. Carefully
          reviewed, detailed reports on various volcanoes are
          published monthly in the Bulletin of the
          Global Volcanism Network.

        Note: Many news agencies do not archive the
        articles they post on the Internet, and therefore
        the links to some sources may not be active.
        To obtain information about the cited articles
        that are no longer available on the Internet
         contact the source.

New Activity/Unrest

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

PHIVOLCS reported that steam emissions were seen rising from Mayon's
crater from 5 to 12 January during periods of clearer weather;
meteorological clouds often prevented observations of the summit. Weak
incandescence from the crater was occasionally seen at night. The

majority of the seismic signals originated from rockfalls and detached

lava fragments rolling down the flanks. Sulfur dioxide emissions
fluctuated between 670 and 1,900 tonnes per day. On 12 January,
PHIVOLCS noted that ground deformation measurements showed a
deflationary trend compared to a 2 December 2009 survey. These
measurements, along with decreased seismicity and sulfur dioxide
output, prompted PHIVOLCS to lower the Alert Level to 2 on 13 January.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Mayon Information from the Global Volcanism Program

NYAMURAGIRA Democratic Republic of Congo 1.408°S, 29.20°E; summit
elev. 3058 m

The Washington VAAC reported a large sulfur dioxide plume in the
vicinity of Nyamuragira and Nyiragongo during 10-11 January. According
to a news article, lava from Nyamuragira continued to flow S and SW on
6 January, and had traveled 21 km to within 7 km of the road between
Goma and Sake. On 7 January ashfall was reported in Goma, 30 km S.

Geologic Summary. Africa's most active volcano, Nyamuragira (Also
spelled Nyamulagira) is a massive basaltic shield volcano N of Lake
Kivu and NW of Nyiragongo volcano. Lava flows from Nyamuragira cover
1,500 sq km of the East African Rift. The 3058-m-high summit is
truncated by a small 2 x 2.3 km summit caldera that has walls up to
about 100 m high. About 40 historical eruptions have occurred since
the mid-19th century within the summit caldera and from numerous
fissures and cinder cones on the volcano's flanks. A lava lake in the
summit crater, active since at least 1921, drained in 1938. Twentieth-
century flank lava flows extend more than 30 km from the summit,
reaching as far as Lake Kivu.

Map

Sources: Washington and Toulouse Volcanic Ash Advisory Centers (VAAC)
personal communication, OpEdNews, Agence France-Presse

Nyamuragira Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

OVPDLF reported that during 5-7 January Piton de la Fournaise
continued to erupt from a vent along a fissure high up on the SW
Dolomieu crater wall. The vent produced lava fountains and flows that
pooled in the bottom of the crater. On 7 January the vent closed, but
the previously erupted lava continued to flow for the next few days.
On 12 January, seismicity decreased and only minor gas emissions
persisted.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 5-6 January a gas-and-ash plume from
Tungurahua rose to an altitude of 6.5 km (21,300 ft) a.s.l. and
drifted NW. The sulfur dioxide emission rate was 3,200 tons per day,
ten times the value measured during the previous months. On 7 January
seismic tremor duration and amplitude increased, and signals
indicative of explosions were detected. On 6 and 7 January,
incandescent blocks were ejected and fell back into the crater. During
8-10 January, cloud cover often prevented observations; on 10 January
a steam-and-ash plume rose to an altitude of 6.5 km (21,300 ft) a.s.l.
and drifted W. Incandescence from the crater was sometimes seen at
night. Ashfall up to 5 mm thick was reported in areas W and SW on 9
and 10 January. Roaring noises and vibrating glass were occasionally
noted during the reporting period.

During 11-12 January, activity increased; ash plumes rose to higher
altitudes and more explosions were detected. Incandescent blocks were
ejected almost 1 km above the crater and 1.5 km away from the crater,
onto the flanks. Gas-and-ash plumes rose to an altitude of 8 km
(26,200 ft) a.s.l. and drifted in multiple directions. Ashfall was
reported in areas to the NNW, W, SW, and S.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

OVSICORI-UNA reported that a phreatic eruption from Turrialba that
began on 5 January was preceded by a day of increased seismicity and
about 30 minutes of almost constant tremor. Two events detected about
15 minutes apart were followed by reports of ashfall as far away as 30
km. Field observations on 6 January revealed that two small vents had
opened and joined together on the SE inner wall of the SW crater. Gas
emission temperatures were more than 350 degrees Celsius. On 8 January
seismic activity and gas emissions decreased. Observations the next
day revealed that the combined vent was about 25 m wide and 80 m long.
Around 60 people had evacuated from nearby farms.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Observatorio Vulcanológico y Sismológico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Turrialba Information from the Global Volcanism Program

Ongoing Activity

BARREN ISLAND Andaman Is 12.278°N, 93.858°E; summit elev. 354 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 11 January an ash plume from Barren Island rose to an altitude of
1.5 km (5,000 ft) a.s.l. and drifted 45 km S.

Geologic Summary. Barren Island, a possession of India in the Andaman
Sea about 135 km NE of Port Blair in the Andaman Islands, is the only
historically active volcano along the N-S-trending volcanic arc
extending between Sumatra and Burma (Myanmar). The 354-m-high island
is the emergent summit of volcano that rises from a depth of about
2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-
km-wide caldera with walls 250-350 m high. The caldera, which is open
to the sea on the W, was created during a major explosive eruption in
the late Pleistocene that produced pyroclastic-flow and -surge
deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course
of historical eruptions. Lava flows fill much of the caldera floor and
have reached the sea along the western coast during historical
eruptions.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Barren Island Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 16 December 2009-4 January 2010 steam-
and-gas plumes from Chaitén's lava-dome complex seen on the web camera
during periods of clear weather rose 1.5 km above the lava domes.
Seismicity, along with occasional block-and-ash flows, indicated that
the lava domes continued to grow. Based on web camera views and
analyses of satellite imagery, the Buenos Aires VAAC reported that on
6 January a plume drifted 50 km ENE at an altitude of 2.1 km (7,000
ft) a.s.l. The next day an ash plume drifted SE and E at the same
altitude.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 6 January an ash plume from Fuego drifted 45 km SE. On 8, 11,
and 12 January, INSIVUMEH reported that explosions produced ash plumes
that rose to altitudes of 4-4.7 km (13,000-15,400 ft) a.s.l. Plumes
drifted as far as 10 km in multiple directions, causing ashfall in
some areas. Incandescent material was ejected to heights up to 75 m.
Some explosions were accompanied by rumbling noises and shock waves
that rattled structures up to 7 km away. Avalanches descended the
flanks.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that a thermal anomaly over Karymsky was detected in

satellite imagery during 30-31 December 2009, 1 January and 4-7
January 2010. Seismic activity was above background levels during 1-8
January. The Level of Concern Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 6-12 January, HVO reported that lava flows from Kilauea's
Thanksgiving Eve Breakout (TEB) and rootless shield complex were seen
above the pali by observers, or detected in satellite images. Lava did
not enter the ocean at Waikupanaha. Incandescence was seen almost
daily coming from multiple locations in Pu'u 'O'o crater. The vent in
Halema'uma'u crater continued to produce a plume that drifted SW, N,
and NE, dropping small amounts of ash, and occasionally fresh spatter,
downwind. The NE-drifting plume resulted in poor air quality in some
communities on 9 January. Incandescence originated from an active and

sometimes sloshing lava surface within an opening on the deep floor of
the vent cavity.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 1-8 January seismic activity from

Kliuchevskoi was above background levels and lava continued to flow

down the ESE flank. Strombolian activity periodically ejected material
500 m above the crater. A new lava flow seen on the NW flank likely
began during 2-3 January. On 5 January two lava flows, on the ESE
flank and NW flanks, were seen in satellite imagery. Satellite imagery
also revealed a large daily thermal anomaly at the volcano. The Level

of Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 8, 11, and 12 January, INSIVUMEH reported that white and blue
fumarolic plumes from Pacaya's MacKenney cone rose up 400 m and
drifted S and SW. Multiple lava flows on the S, SW, and W flanks
traveled 25-200 m. Incandescence was noted at night from one of the
inter-crater cones on 8 January and from MacKenney cone on 11 and 12
January.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that on 10 and 11 January emissions of steam and gas
from Popocatépetl contained minor amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that activity from Rabaul caldera's Tavurvur cone was at

a low level during 1-10 January. No emissions from the crater were
observed on most days, but white steam plumes accompanied by blue
plumes were occasionally seen. On 8 January, ash emissions rose less

than 200 m above the cone.

Geologic Summary. The low-lying Rabaul caldera on the tip of the

Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

On 5 January, AVO reported that because of low levels of seismic
activity from Redoubt, along with the lack of any other outward signs
of progressing unrest, the Volcanic Alert Level was lowered to Normal
and the Aviation Color Code was lowered to Green.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during

6-12 January multiple explosions from Sakura-jima often produced

plumes that rose to altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l.

and drifted SE and E. On 10 January a pilot reported that an ash plume
drifted SE at an altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that incandescent avalanches traveled down the SW
flanks of Santa María's Santiaguito lava dome complex on 8 January. A
few explosions on 11 and 12 January produced ash plumes that rose to
altitudes of 3.1-3.4 km (10,200-11,200 ft) a.s.l. and drifted S, SE,
and SW. Avalanches from a lava flow descended the W flank of the dome.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 1-8 January seismic activity from Shiveluch

was above background levels, possibly indicating ash plumes rising to

an altitude of 7.5 km (24,600 ft) a.s.l. Fumarolic activity was

occasionally seen when the weather was clear. Analyses of satellite
imagery revealed a large daily thermal anomaly from the lava dome and

a gas-and-steam plume that drifted 40 km SW on 6 January. Ashfall was
reported in Klyuchi (about 45 km SW) on 4 January. The Level of

Concern Color Code remained at Orange. Based on information from KEMSD

and analyses of satellite imagery, the Tokyo VAAC reported that during
6-11 January eruptions produced plumes that rose to altitudes of
4.3-6.4 km (14,000-21,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 31 December-8 January pyroclastic flows from
the Soufrière Hills lava dome continued to travel predominantly down
areas to the N including Whites Ghaut (NE), Farrells plain (N), and
Tyers Ghaut (NW). Observations on 2 January showed that a 40-m-high,
150-m-wide lobe of lava had been extruded northwards onto the N summit
of the dome. This lobe was the main source of rockfall and pyroclastic
flow activity. On 3 and 4 January ash plumes rose to an altitude of
4.6 km (15,000 ft) a.s.l. and drifted NW. Ashfall occurred in areas to
the NW several times during the reporting period.

On 8 January, a large pyroclastic flow event occurred after a
collapsing fountain of tephra was observed on the NE side of the
volcano. Pyroclastic flows traveled NE down Whites Bottom Ghaut to the
sea and down Tuitts Ghaut to within a few hundred meters of the sea.
Pyroclastic flows also traveled NW down Tyers Ghaut and into the
Belham Valley, W towards Plymouth, and E down the Tar River valley.
The event lasted about 11 minutes and seismicity returned to
background levels quickly. There was no precursory seismicity
associated with the event. Ashfall was reported in inhabited areas in
the NW.

Seismic signals indicated that another explosion occurred on 10
January. Pyroclastic flows descended the NE, NW, and W flanks, and
ashfall was reported in areas to the NW. Another explosion later that
day also caused ashfall in inhabited areas. The Hazard Level remained
at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 6-9 and 11 January. Plumes rose to an altitude of
1.8 km (6,000 ft) a.s.l. on 6 and 9 January and drifted E.

Map

Global Volcanism Program — Department of Mineral Sciences —

leona...@gmail.com

unread,

Jan 20, 2010, 10:07:46 PM1/20/10

to

SI / USGS Weekly VolcanicActivityReport

13 January-19 January 2010
NewVolcanosErupting This Week: 5

Total Active 17

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

|Kharimkotan, Kuril Islands (Russia)

| Nyamuragira, Democratic Republic of Congo

| Soufrière Hills, Montserrat

| Tungurahua, Ecuador
| Turrialba, Costa Rica

OngoingActivity:

| Arenal, Costa Rica
| Chaitén, Southern Chile

| Gaua, Banks Islands (SW Pacific)

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Planchón-Peteroa, Central Chile-Argentina border

| Rabaul, New Britain
| Sakura-jima, Kyushu
| Sangay, Ecuador

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please see the
GVP Home Page for news of the latest significantactivity.

The Weekly VolcanicActivityReport is a cooperative
project between the Smithsonian's Global Volcanism
Program and the US Geological Survey'sVolcano
Hazards Program.

Updated by 2300 UTC every Wednesday, notices of

volcanicactivity posted on these pages are preliminary

and subject to change as events are studied in more
detail.
This is not a comprehensivelistof all of Earth's
volcanoes erupting during the week, but rather a summary

of activity at volcanoes that meet criteria discussed in

detail in the "Criteria and Disclaimers" section.
Carefully
reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the
Global Volcanism Network.

Note: Many news agencies do not archive the
articles they post on the Internet, and therefore
the links to some sources may not be active.
To obtain information about the cited articles
that are no longer available on the Internet
contact the source.

NewActivity/Unrest

KHARIMKOTAN Kuril Islands (Russia) 49.12°N, 154.508°E; summit elev.
1145 m

SVERT reported that a thermal anomaly from Kharimkotan's Severgin cone
was detected by satellite on 15 January.

Geologic Summary. The 8 x 12 km island of Kharimkotan (also spelled
Harimkotan) in the northern Kuriles consists of a stratovolcano cut by
two breached depressions on the east and NW sides. These horseshoe-
shaped craters were formed by slope failure, which produced debris-
avalanche deposits that form large broad peninsulas on the east and NW
coasts. Evidence of additional slope failures followed by plinian
eruptions are found in sea cliffs of the island. Historical explosive
eruptions have occurred since the early 18th century. A central cone,
Severgin, was largely destroyed during the 1933 eruption, one of the
largest in the Kuril Islands during historical time. Impact of a
debris avalanche into the sea from the collapse of Severgin produced a
tsunami that swept the island's coast and reached Onekotan and
Paramushir Islands, killing two persons. A large lava dome emplaced
during the 1933 eruption now fills the head of the eastern crater.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Kharimkotan Information from the Global Volcanism Program

NYAMURAGIRA Democratic Republic of Congo 1.408°S, 29.20°E; summit
elev. 3058 m

Based on analyses of satellite imagery, the Toulouse VAAC reported
that on 18 January sulfur dioxide-and-steam plumes from Nyamuragira
possibly contained ash. An ash cloud was visible in satellite imagery
the next day.

Geologic Summary. Africa's most active volcano, Nyamuragira (Also

spelled Nyamulagira) is a massive basaltic shield volcano N of Lake
Kivu and NW of Nyiragongo volcano. Lava flows from Nyamuragira cover
1,500 sq km of the East African Rift. The 3058-m-high summit is
truncated by a small 2 x 2.3 km summit caldera that has walls up to
about 100 m high. About 40 historical eruptions have occurred since
the mid-19th century within the summit caldera and from numerous
fissures and cinder cones on the volcano's flanks. A lava lake in the
summit crater, active since at least 1921, drained in 1938. Twentieth-
century flank lava flows extend more than 30 km from the summit,
reaching as far as Lake Kivu.

Map

Source: Toulouse Volcanic Ash Advisory Center (VAAC)

Nyamuragira Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 8-15 January activity from the Soufrière
Hills lava dome increased significantly. One explosion on 8 January
and two on 10 January generated ash plumes that rose to altitudes of
5.5-7.6 km (18,000-25,000 ft) a.s.l. Ash fell in occupied areas to the
NW, along with lapilli fall on 10 January. The explosions occurred
from an area on the NE side of the volcano. Pyroclastic flows from
column collapses moved rapidly NE (down Whites Bottom and Tuitts
Ghaut), NW (down Tyers Ghaut and Belham Valley), W (down Gages Ghaut),
and the SE (down the Tar River Valley). After the explosions activity
decreased until 12 January, when cycles of increased numbers of
rockfalls, pyroclastic flows, and ash venting were noted.

Observations during 8-15 January revealed that lava-dome growth
resumed at the top, central part of the dome. On 18 January, a partial
lava-dome collapse generated a pyroclastic flow that traveled W down
Gages Valley, into Spring Ghaut, and then WSW down Aymers Ghaut,
reaching the sea. Ash plumes rose to an altitude of 3 km (10,000 ft)
a.s.l. and drifted W. Smoke from burning houses in Kinsale was visible
after the event. The Hazard Level remained at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 13-14 January explosions from Tungurahua
ejected incandescent material 1 km above and 1.5 km away from the
crater, onto the flanks. Explosions produced noises resembling "cannon
shots" and caused windows and structures to vibrate. Gas-and-ash
plumes rose to altitudes of 7-8 km (23,000-26,000 ft) a.s.l. and
drifted W and SW, causing ashfall. On 15 January, although
meteorological clouds mostly prevented observations, an ash plume was
seen rising to an altitude of 6 km (19,700 ft) a.s.l. Cloud cover
prevented observations during the next two days. On 17 January,
ashfall was reported in areas W and SW. Lahars descended drainages to
the W and NW, causing the road to Baños to close. On 18 January,
Strombolian activity ejected incandescent blocks and an ash plume rose
to an altitude of 6 km (19,700 ft) a.s.l. Explosions caused windows
and structures to vibrate. Ashfall was reported in areas W and SW on
18 and 19 January.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

Based on multiple METAR weather notices during the previous few days,
the Washington VAAC reported on 16 January that gas plumes containing
some ash rose from Turrialba. Ash was not seen in satellite imagery
that day or the next.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Turrialba Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during December activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian
eruptions, and occasional avalanches that traveled down the W and SW
flanks. Acid rain and small amounts of ejected pyroclastic material
affected the NE and SE flanks. Avalanches from lava-flow fronts
traveled down the SW flanks. Crater D produced only fumarolic
activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the
Buenos Aires VAAC reported that an ash plume from Chaitén's lava-dome
complex drifted NNE on 14 January at an altitude of 1.8 km (6,000 ft)
a.s.l. A steam-and-gas plume drifted NE at the same altitude the next
day.

Geologic Summary. Chaitén is a small, glacier-free caldera with a

Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

On 13 January, Vanuatu Geohazards Observatory reported that ash
emissions that had become denser and darker on 14 December continued.
Ashfall persisted in the W part of the island and satellite imagery
showed gas emissions. The Vanuatu Volcano Alert Level (VVAL) remained

at 2 (on a scale of 0-4).

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Vanuatu Geohazards Observatory

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 8-15 January seismic activity from Karymsky
was above background levels, possibly indicating that ash plumes rose
to an altitude of 3 km (10,000 ft) a.s.l. Analyses of satellite
imagery revealed an almost daily thermal anomaly over the volcano and
ash plumes that drifted 113 km SE on 12 and 13 January. The Level of

Concern Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 13-19 January, HVO reported an active lava surface about 200 m
below a vent in the floor of Kilauea's Halema'uma'u crater. The lava
surface occasionally spattered, and both rose and drained through a
hole in the cavity floor. A plume from the vent drifted mainly SW,

dropping small amounts of ash, and occasionally fresh spatter,

downwind. On 14 January, the lava surface suddenly rose to very high
levels multiple times; the highest level was about 120 m below the
floor of Halema'uma'u crater. Thermal anomalies from the areas above
the pali, detected from satellites on the same day, indicated that
lava emissions from the TEB vent had resumed. Lava flows were noted
during 17-19 January.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 8-15 January seismic activity from

Kliuchevskoi was above background levels and lava continued to flow

down the NW flank. Strombolian activity periodically ejected material
above the crater. Phreatic explosions were seen from the front of the
lava flow, which was about 1.2 km in length. Satellite imagery also
revealed a large daily thermal anomaly at the volcano. During 12-14
January, gas-and-steam plumes rose to an altitude of 6.8 km (22,300
ft) a.s.l. and drifted E. The Level of Concern Color Code remained at
Orange. Based on information from the Yelizovo Airport (UHPP), the
Tokyo VAAC reported that on 18 January an ash plume rose to an
altitude of 9 km (30,000 ft) a.s.l. and drifted N.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

Based on pilot reports and photographs SERNAGEOMIN reported on 13
January that fumarolic plumes from Planchón-Peteroa rose 250 m high on
4, 6, and 7 January. Increased fumarolic activity is common on the
warmest days in the summer when snow melts in the crater and more
steam is produced.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Planchón-Peteroa Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

Based on a Port Moresby Met Office notice, the Darwin VAAC reported
that an ash plume from Rabaul caldera's Tavurvur cone rose 2.4 km
(8,000 ft) a.s.l.

Geologic Summary. The low-lying Rabaul caldera on the tip of the

Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during

13-19 January multiple explosions from Sakura-jima often produced
plumes that rose to altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l.
and drifted SE and E. On 16 and 18 January, pilots reported that ash
plumes drifted SE at altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on pilot observations, the Washington VAAC reported that on 14
January an ash plume from Sangay rose to an altitude of 7.3 km (24,000
ft) a.s.l. Ash was not identified in satellite imagery, although
weather clouds were present in the area.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 8-15 January seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 6.2 km (20,300 ft) a.s.l. Analyses of

satellite imagery revealed a large daily thermal anomaly from the lava

dome and an ash plume that drifted 8 km SW on 13 January. The Level of

Concern Color Code remained at Orange. Based on information from

KEMSD, the Tokyo VAAC reported that on 18 January an eruption produced
a plume that rose to an altitude of 4.9 km (16,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 13 and 16-17 January. Details of possible

resulting emissions were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-

jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

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SI / USGS Weekly Volcanic Activity Report

20 January-26 January 2010

New Activity/Unrest:

| Soufrière Hills, Montserrat
| Tungurahua, Ecuador

Ongoing Activity:

| Barren Island, Andaman Is

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile

| Fuego, Guatemala

| Gaua, Banks Islands (SW Pacific)
| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Llaima, Central Chile

| Sakura-jima, Kyushu
| Santa María, Guatemala

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays, please
see the GVP Home Page for news of the

latest significant activity.

The Weekly Volcanic Activity Report is a

cooperative project between the Smithsonian's
Global Volcanism Program and the US

Geological Survey's Volcano Hazards Program.

Updated by 2300 UTC every Wednesday,

notices of volcanic activity posted on these pages

are preliminary and subject to change as events
are studied in more detail.

This is not a comprehensive list of all of Earth's

volcanos erupting during the week, but rather a

summary of activity at volcanoes that meet
criteria discussed in detail in the "Criteria and
Disclaimers" section. Carefully reviewed,
detailed reports on various volcanoes are
published monthly in the Bulletin of the Global
Volcanism Network.

Note: Many news agencies do not archive the
articles they post on the Internet, and therefore
the links to some sources may not be active. To
obtain information about the cited articles that
are no longer available on the Internet contact
the source.

New Activity/Unrest

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 15-22 January activity from the Soufrière
Hills lava dome was variable as dome growth continued. Cycles of
vigorous ash venting, rockfalls, and pyroclastic flows occurred every
six to eight hours. Light ashfall occasionally occurred in NW
Montserrat. On 18 January, a small lava-dome collapse from the W side
of the volcano generated a large pyroclastic flow that traveled 4 km
down Gages Valley into Spring Ghaut, and into Aymer's Ghaut, reaching
the sea at Kinsale to the S of Plymouth. Ash clouds associated with
the pyroclastic flows rose to an altitude of 3 km (10,000 ft) a.s.l.
Several houses in Kinsale seen from a helicopter on 22 January had
been buried or were burning. The Hazard Level remained at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 20-26 January explosions from Tungurahua
were detected by the seismic network. Inclement weather often
prevented observations of the volcano; occasionally ash plumes were
seen rising to altitudes of 5.3-8 km (17,400-26,200 ft) a.s.l. Ashfall
was noted almost daily in areas to the SW and sometimes to the W and
NW. Roaring noises, sounds resembling "cannon shots," and vibrating
windows were reported. During 20-23 January lava fountains and
explosions ejected incandescent blocks that fell onto and rolled down
the flanks. Blocks were also seen rolling down the flanks on 24 and 25
January. On 26 January, an explosion generated an ash plume that rose
to an altitude of 9 km (30,000 ft) a.s.l. Ashfall was reported in
areas to the NW, W, and WSW.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Ongoing Activity

BARREN ISLAND Andaman Is 12.278°N, 93.858°E; summit elev. 354 m

Based on a pilot observation, the Darwin VAAC reported that on 23
January an ash plume from Barren Island rose to an altitude of 3 km
(10,000 ft) a.s.l. Ash was not identified in satellite imagery.

Geologic Summary. Barren Island, a possession of India in the Andaman
Sea about 135 km NE of Port Blair in the Andaman Islands, is the only
historically active volcano along the N-S-trending volcanic arc
extending between Sumatra and Burma (Myanmar). The 354-m-high island
is the emergent summit of volcano that rises from a depth of about
2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-
km-wide caldera with walls 250-350 m high. The caldera, which is open
to the sea on the W, was created during a major explosive eruption in
the late Pleistocene that produced pyroclastic-flow and -surge
deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course
of historical eruptions. Lava flows fill much of the caldera floor and
have reached the sea along the western coast during historical
eruptions.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Barren Island Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.

748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 23 January an ash plume from Batu Tara rose to an altitude of 1.5
km (5,000 ft) a.s.l. and drifted 25 km E.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

SERNAGEOMIN reported that during 5-19 January Chaitén's lava-dome
complex continued to grow, although possibly at rates lower than
during previous weeks. The magnitude and number of hybrid earthquakes
decreased. The Alert Level remained at Red.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Chaitén Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 22 January, INSIVUMEH reported that explosions from Fuego produced
gray plumes that rose to altitudes of 4.4-4.8 km (14,400-15,700 ft)
a.s.l. and drifted 5-12 km SW. Incandescent material was ejected to
heights of 75 m and avalanches descended the flanks. Based on analyses
of satellite imagery, the Washington VAAC reported that on 25 January
a dense ash cloud drifted 15 km NW. The next day an ash cloud drifted
11 km W.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,

e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

Based on analyses of satellite imagery and pilot observations, the
Wellington VAAC reported that on 21 January an ash plume from Gaua
rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted S. An ash
cloud was seen in satellite imagery on 26 January.

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 15-22 January seismic activity from

Karymsky was above background levels, possibly indicating that ash
plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Analyses of

satellite imagery revealed a daily thermal anomaly over the volcano.

The Level of Concern Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 20-26 January, HVO reported an active lava surface about 200 m

below a vent in the floor of Kilauea's Halema'uma'u crater. The lava
surface occasionally spattered, and both rose and drained through a

hole in the cavity floor. A plume from the vent drifted multiple
directions, dropping small amounts of ash, and occasionally fresh
spatter, downwind. Lava from beneath the Thanksgiving Eve Breakout
(TEB) and rootless shield complex flowed SE through a lava tube
system. Thermal anomalies detected by satellite and visual
observations revealed active lava flows on top of the pali from lava-
tube breakouts.

During an overflight of Pu'u 'O'o crater on 19 January scientists saw
a recent but inactive lava flow across the bottom of the crater. On 22
January a small part of the crater rim collapsed in front of the web
camera, revealing an incandescent vent at the base of the E wall.
During 23-26 January, incandescence was seen from the vent, as well as
from high on the E wall, the crater floor, and low on the S wall.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 15-22 January seismic activity from

Kliuchevskoi was above background levels and lava continued to flow
down the NW flank. Strombolian activity periodically ejected material

300 m above the crater. Phreatic explosions from the front of the lava
flow ejected material that rose to altitudes of 4.5-8 km
(14,800-26,200 ft) a.s.l. Satellite imagery also revealed a large
daily thermal anomaly at the volcano. The Level of Concern Color Code

remained at Orange. Based on information from the Yelizovo Airport

(UHPP) and analyses of satellite imagery, the Tokyo VAAC reported that
during 22-23 January ash plumes rose to altitudes of 7-10.1 km
(23,000-33,000 ft) a.s.l. and drifted NE.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

On 22 January, SERNAGEOMIN reported that seismicity from Llaima had
decreased during the previous few weeks to background levels. The
Alert Level was lowered to Green, (Level 2) on a three-color scale.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

During 26 December 2009-9 January 2010, a visitor to Sakura-jima
observed and photographed Strombolian and Vulcanian explosions from
Showa crater. Based on information from JMA, the Tokyo VAAC reported
that during 20-26 January multiple explosions often produced plumes
that rose to altitudes of 1.2-2.4 km (4,000-8,000 ft) a.s.l. and
drifted NE, E, SE, and S. On 23 January, a pilot reported that an ash
plume drifted SE at an altitude of 1.8 km (6,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Richard Roscoe,
Photo Volcanica

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 21 January ashfall was reported in areas
near Santa María's Santiaguito lava dome complex. The next day an
explosion produced an ash plume that rose to an altitude of 3.2 km
(10,500 ft) a.s.l. and drifted SW. The Washington VAAC reported that
an ash plume seen on satellite imagery drifted less than 10 km.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,

e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 15-22 January seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 4.7 km (15,400 ft) a.s.l. Analyses of

satellite imagery revealed a large daily thermal anomaly from the lava

dome. The Level of Concern Color Code remained at Orange. Based on
information from KEMSD, the Tokyo VAAC reported that during 23-24 and
26 January eruptions produced plumes that rose to altitudes of 3-4.6
km (10,000-15,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

During 29-30 December 2009, a visitor to Suwanose-jima observed and
photographed multiple Strombolian explosions and ash eruptions from On-
take (Otake) crater. Based on information from JMA, the Tokyo VAAC
reported explosions during 22-26 January. On 24 and 26 January, plumes
rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Richard Roscoe,
Photo Volcanica

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SI / USGS Weekly Volcanic Activity Report

20 January-26 January 2010

New Activity/Unrest:

| Soufri�re Hills, Montserrat
| Tungurahua, Ecuador

Ongoing Activity:

| Barren Island, Andaman Is
| Batu Tara, Komba Island (Indonesia)

| Chait�n, Southern Chile

| Santa Mar�a, Guatemala

New Activity/Unrest

MVO reported that during 15-22 January activity from the Soufri�re

Hills lava dome was variable as dome growth continued. Cycles of
vigorous ash venting, rockfalls, and pyroclastic flows occurred every
six to eight hours. Light ashfall occasionally occurred in NW
Montserrat. On 18 January, a small lava-dome collapse from the W side
of the volcano generated a large pyroclastic flow that traveled 4 km
down Gages Valley into Spring Ghaut, and into Aymer's Ghaut, reaching
the sea at Kinsale to the S of Plymouth. Ash clouds associated with
the pyroclastic flows rose to an altitude of 3 km (10,000 ft) a.s.l.
Several houses in Kinsale seen from a helicopter on 22 January had
been buried or were burning. The Hazard Level remained at 4.

Geologic Summary. The complex dominantly andesitic Soufri�re Hills

volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated

with dome growth predominate in flank deposits at Soufri�re Hills. Non-

eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufri�re Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467�S, 78.442�W; summit elev. 5023 m

The IG reported that during 20-26 January explosions from Tungurahua
were detected by the seismic network. Inclement weather often
prevented observations of the volcano; occasionally ash plumes were
seen rising to altitudes of 5.3-8 km (17,400-26,200 ft) a.s.l. Ashfall
was noted almost daily in areas to the SW and sometimes to the W and
NW. Roaring noises, sounds resembling "cannon shots," and vibrating
windows were reported. During 20-23 January lava fountains and
explosions ejected incandescent blocks that fell onto and rolled down
the flanks. Blocks were also seen rolling down the flanks on 24 and 25
January. On 26 January, an explosion generated an ash plume that rose
to an altitude of 9 km (30,000 ft) a.s.l. Ashfall was reported in
areas to the NW, W, and WSW.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of

Ba�os on the N side of the volcano.

Map

Source: Instituto Geof�sico-Escuela Polit�cnica Nacional (IG)

Ongoing Activity

Map

SERNAGEOMIN reported that during 5-19 January Chait�n's lava-dome

complex continued to grow, although possibly at rates lower than
during previous weeks. The magnitude and number of hybrid earthquakes
decreased. The Alert Level remained at Red.

Geologic Summary. Chait�n is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chait�n on the Gulf

of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the

bay of Chait�n, and the high point on its southern rim reaches 1122 m.

Map

Source: Servicio Nacional de Geolog�a y Miner�a (SERNAGEOMIN)

Chait�n Information from the Global Volcanism Program

FUEGO Guatemala 14.473�N, 90.880�W; summit elev. 3763 m

On 22 January, INSIVUMEH reported that explosions from Fuego produced
gray plumes that rose to altitudes of 4.4-4.8 km (14,400-15,700 ft)
a.s.l. and drifted 5-12 km SW. Incandescent material was ejected to
heights of 75 m and avalanches descended the flanks. Based on analyses
of satellite imagery, the Washington VAAC reported that on 25 January
a dense ash cloud drifted 15 km NW. The next day an ash cloud drifted
11 km W.

Geologic Summary. Volc�n Fuego, one of Central America's most active

Map

the 24 cu km Curacaut�n Ignimbrite. More than 40 scoria cones dot the

volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geolog�a y Miner�a (SERNAGEOMIN)

Map

near Santa Mar�a's Santiaguito lava dome complex. The next day an

explosion produced an ash plume that rose to an altitude of 3.2 km
(10,500 ft) a.s.l. and drifted SW. The Washington VAAC reported that
an ash plume seen on satellite imagery drifted less than 10 km.

Geologic Summary. Symmetrical, forest-covered Santa Mar�a volcano is

one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa Mar�a Information from the Global Volcanism Program

Map

=============================================
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SI / USGS Weekly Volcanic Activity Report

27 January- 2 February 2010

2 new + 11 Ongoing = 13 Actives

New Activity/Unrest:

| Nyiragongo, Democratic Republic of Congo
| Tungurahua, Ecuador

Ongoing Activity:

| Gaua, Banks Islands (SW Pacific)
| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Nyamuragira, Democratic Republic of Congo

| Popocatépetl, México

| Sakura-jima, Kyushu
| Sangay, Ecuador
| Shiveluch, Central Kamchatka (Russia)

| Soufrière Hills, Montserrat
| Suwanose-jima, Ryukyu Islands (Japan)

New Activity/Unrest

NYIRAGONGO Democratic Republic of Congo 1.52°S, 29.25°E; summit elev.
3470 m

During 27 January-2 February, the MODIS sensor aboard the Earth
Observing System (EOS) satellite continued to frequently detect
thermal anomalies from Nyiragongo, likely from lava lake activity.
Based on analyses of satellite imagery, the Toulouse VAAC reported
that during 30-31 January a diffuse plume drifted 240 km W.

Geologic Summary. One of Africa's most notable volcanoes, Nyiragongo
contained an active lava lake in its deep summit crater that drained
catastrophically through its outer flanks in 1977. In contrast to the
low profile of its neighboring shield volcano, Nyamuragira, Nyiragongo
displays the steep slopes of a stratovolcano. Benches in the steep-
walled, 1.2-km-wide summit crater mark the levels of former lava
lakes, which have been observed since the late 19th century. About 100
parasitic cones are located on the volcano's flanks and along a NE-SW
zone extending as far as Lake Kivu. Monitoring is done from a small
observatory building located in Goma, ~18 km S of the Nyiragongo
crater.

Map

Sources: Toulouse Volcanic Ash Advisory Center (VAAC), Hawai'i
Institute of Geophysics and Planetology (HIGP) Moderate Resolution
imaging Spectroradiometer (MODIS) Thermal Alert System

Nyiragongo Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 26 January-2 February explosions from

Tungurahua were detected by the seismic network. Inclement weather

occasionally prevented observations of the volcano; ash plumes were
seen rising to altitudes no higher than 8 km (26,200 ft) a.s.l.
Ashfall was noted almost daily in areas to the SW, W, and NW. Roaring
noises and sounds resembling "cannon shots" were reported. During 26
and 28-30 January lava fountains were seen and sometimes ejected
incandescent blocks that fell onto and rolled down the flanks. On 31
January, a lahar descended the Chontapamba drainage to the W.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Ongoing Activity

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

On 29 January, the Vanuatu Geohazards Observatory reported significant
changes in Gaua's activity over the previous two weeks. They noted
that since 16 January more gas was emitted and multiple explosions
produced denser and darker ash plumes. During 22-29 January, the water
level in the river to the E that Lake Letas feeds rose 10 cm. Gas-and-
ash plumes rose 3 km and drifted S and W. On 24 January nearby
villagers reported seeing ejected material from Strombolian activity.
The Wellington VAAC reported that on 27 January an ash cloud was seen
on satellite imagery. Strong explosions were seen and heard from East
Gaua on 29 January. According to the VAAC, the Vanuatu Geohazards
Observatory reported that gas-and-ash plumes rose to altitudes of 3 km
(10,000 ft) a.s.l. and drifted S and W that same day.

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Sources: Vanuatu Geohazards Observatory, Wellington Volcanic Ash
Advisory Center (VAAC)

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 22-29 January seismic activity from
Karymsky was above background levels and possibly indicated weak ash
explosions. Analyses of satellite imagery revealed a thermal anomaly
over the volcano during 21-25 and 27 January. The Level of Concern

Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 27 January-2 February, HVO reported an active lava surface

about 200 m below a vent in the floor of Kilauea's Halema'uma'u
crater. The lava surface occasionally spattered, and both rose and
drained through a hole in the cavity floor. A plume from the vent

drifted N, NW, and W, dropping small amounts of ash, and occasionally
fresh spatter, downwind. Measurements indicated that the sulfur
dioxide emission rate at the summit remained elevated; 400 and 1,000
tonnes per day were measured on 28 January and 1 February,
respectively. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless

shield complex flowed over 3 km SE through a lava tube system before
breaking out onto the surface. Thermal anomalies detected by satellite
and visual observations revealed active lava flows on top of and on
the pali; lava burned forest on the W side of the TEB flows.
Incandescence was seen from a vent low on the S wall of Pu'u 'O'o
crater.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 22-29 January seismic activity from

Kliuchevskoi was above background levels and lava continued to flow
down the NW flank. Strombolian activity periodically ejected material

200 m above the crater, and phreatic explosions occurred from the
front of the lava flow. Satellite imagery revealed a large daily
thermal anomaly at the volcano. Ashfall was reported in Klyuchi, about
30 km to the NE, on 22 January. The Level of Concern Color Code
remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active

volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

NYAMURAGIRA Democratic Republic of Congo 1.408°S, 29.20°E; summit
elev. 3058 m

During 27 January-2 February, the MODIS sensor aboard the Earth
Observing System (EOS) satellite frequently detected thermal anomalies
from Nyamuragira. The Toulouse VAAC reported that a diffuse ash plume
was seen on satellite imagery on 29 January.

Geologic Summary. Africa's most active volcano, Nyamuragira (Also
spelled Nyamulagira) is a massive basaltic shield volcano N of Lake
Kivu and NW of Nyiragongo volcano. Lava flows from Nyamuragira cover
1,500 sq km of the East African Rift. The 3058-m-high summit is
truncated by a small 2 x 2.3 km summit caldera that has walls up to
about 100 m high. About 40 historical eruptions have occurred since
the mid-19th century within the summit caldera and from numerous
fissures and cinder cones on the volcano's flanks. A lava lake in the
summit crater, active since at least 1921, drained in 1938. Twentieth-
century flank lava flows extend more than 30 km from the summit,
reaching as far as Lake Kivu.

Map

Sources: Toulouse Volcanic Ash Advisory Center (VAAC), Hawai'i
Institute of Geophysics and Planetology (HIGP) Moderate Resolution
imaging Spectroradiometer (MODIS) Thermal Alert System

Nyamuragira Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 27-31 January and 1 February emissions

of steam and gas from Popocatépetl contained minor amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for

smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 27
January-2 February multiple explosions from Sakura-jima produced
plumes that rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l.
and drifted SE, E, and NE. During 27-29 January and 1-2 February,
pilots reported that ash plumes sometimes drifted SE and S at
altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on pilot observations, the Washington VAAC reported that on 2
February an ash plume from Sangay rose to an altitude of 8.2 km
(27,000 ft) a.s.l. Ash was not identified in satellite imagery,

although weather clouds were present in the area.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 22-29 January seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 4.6 km (15,100 ft) a.s.l. Fumarolic activity
was occasionally observed. Analyses of satellite imagery revealed a

large daily thermal anomaly from the lava dome. The Level of Concern
Color Code remained at Orange. Based on information from KEMSD, the

Tokyo VAAC reported that during 29-30 January eruptions produced
plumes that rose to altitudes of 4.9-5.8 km (16,000-19,000 ft) a.s.l.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 22-29 January activity from the Soufrière
Hills lava dome was variable as the lava dome continued to grow.

Cycles of vigorous ash venting, rockfalls, and pyroclastic flows

occurred every five to seven hours. Pyroclastic flows traveled down
multiple valleys, including Whites Ghaut to the NE, and W down Gages
into Spring Ghaut. The increasing number of pyroclastic flows that
traveled E down the Tar River Valley, frequently reaching the sea,
were attributed to new lava-dome growth in the SE part of the lava
dome. Ash fell across most of Montserrat on 23 January. Vigorous
steaming from hot pyroclastic flows emplaced in the Belham Valley on 8
January was caused by heavy rains on 25 January. Small steam
explosions generated steam plumes that sometimes contained ash. The

Hazard Level remained at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 27 January-2 February. On 27 January, plumes rose
to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted W.
Plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 29 January.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

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SI / USGS Weekly Volcanic Activity Report

3 February- 9 February 2010

3 new + 11 Ongoing = 14 Actives

Sally Kuhn Sennert - Weekly Report Editor

New Activity/Unrest:

| Bezymianny, Central Kamchatka (Russia)
| Fukutoku-Okanoba, Volcano Is
| Pacaya, Guatemala

Ongoing Activity:

| Dukono, Halmahera
|Galeras, Colombia

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Sakura-jima, Kyushu
| Sarychev Peak, Matua Island

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Suwanose-jima, Ryukyu Islands (Japan)

| Tungurahua, Ecuador

This page is updated on Wednesdays, please
see the GVP Home Page for news of the
latest significant activity.

The Weekly Volcanic Activity Report is a
cooperative project between the Smithsonian's
Global Volcanism Program and the US

Geological Survey'sVolcanoHazards Program.

Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages
are preliminary and subject to change as events
are studied in more detail.
This is not a comprehensive list of all of Earth's
volcanos erupting during the week, but rather a
summary of activity at volcanoes that meet
criteria discussed in detail in the "Criteria and
Disclaimers" section. Carefully reviewed,
detailed reports on various volcanoes are
published monthly in the Bulletin of the Global
Volcanism Network.

Note: Many news agencies do not archive the
articles they post on the Internet, and therefore
the links to some sources may not be active. To
obtain information about the cited articles that
are no longer available on the Internet contact
the source.

New Activity/Unrest

BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit
elev. 2882 m

KVERT reported that during 29-30 January and 2 February a thermal
anomaly from Bezymianny's lava dome was detected in satellite imagery.
The anomaly was larger during 7-8 February, prompting KVERT to raise
the Level of Concern Color Code to Orange. Strong activity from
Kliuchevskoi volcano had obscured seismic signals from Bezymianny
since 4 January.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny
volcano had been considered extinct. Three periods of intensified
activity have occurred during the past 3,000 years. The latest period,
which was preceded by a 1,000-year quiescence, began with the dramatic
1955-56 eruption. That eruption, similar to the 1980 event at Mount
St. Helens, produced a large horseshoe-shaped crater that was formed
by collapse of the summit and an associated lateral blast. Subsequent
episodic but ongoing lava-dome growth, accompanied by intermittent
explosive activity and pyroclastic flows, has largely filled the 1956
crater.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bezymianny Information from the Global Volcanism Program

FUKUTOKU-OKANOBA Volcano Is 24.28°N, 141.485°E; summit elev. -14 m

According to news articles, JMA reported Surtseyan explosions from
Fukutoku-Okanoba, 5 km NE of the island of Minami-Iwo-jima, on 3
February. Steam-and-ash plumes rose 100 m a.s.l. and the surrounding
sea turned yellow-green. Video footage of the event was captured by
people aboard a Japanese Coast Guard patrol boat. One article stated
that the sea in the area had regularly changed colors since the 1950s,
most recently in December 2009.

Geologic Summary. Fukutoku-Okanoba is a submarine volcano located 5 km
NE of the pyramidal island of Minami-Iwo-jima. Water discoloration is
frequently observed from the volcano, and several ephemeral islands
have formed in the 20th century. The first of these formed Shin-Iwo-
jima ("New Sulfur Island") in 1904, and the most recent island was
formed in 1986. Fukutoku-Okanoba is part of an elongated edifice with
two major topographic highs trending NNW-SSE and is a trachyandesitic
volcano geochemically similar to Iwo-jima.

Map

Sources: ITN, The Mainichi Daily News

Fukutoku-Okanoba Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that activity from Pacaya consisting of effusion of
lava flows, the source of which had migrated towards the S from the N
flank since April 2006, ceased on 30 January 2010. On 5 February,
Strombolian explosions from MacKenney cone ejected material 30 m into
the air and lava from the crater moved down the flank. The activity
was heard in the village of San Francisco de Sales, 5 km N. A new lava
flow originating from a depression on the NE flank was seen on 6
February.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

Ongoing Activity

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that during 5-6 February ash plumes from
Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted
55-150 km SW and W.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

On 9 February, INGEOMINAS lowered the Alert Level for Galeras to III

(Yellow; "changes in the behavior of volcanic activity"). During the

previous few days, seismicity was low and sulfur dioxide emissions
were low to moderate.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 29 January-5 February seismic activity from

Karymsky was above background levels and possibly indicated weak ash
explosions. Analyses of satellite imagery revealed a thermal anomaly

over the volcano on 28 January and 1 February. The Level of Concern

Color Code remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 3-9 February, HVO reported an active lava surface about 200 m

below a vent in the floor of Kilauea's Halema'uma'u crater. The lava
surface occasionally spattered, and both rose and drained through

holes in the cavity floor. A plume from the vent drifted mainly SW,

dropping small amounts of ash, and occasionally fresh spatter,
downwind. Measurements indicated that the sulfur dioxide emission rate

at the summit remained elevated; 1,200 and 700 tonnes per day were
measured on 4 and 8 February, respectively. The 2003-2007 average rate

was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless
shield complex flowed over 3 km SE through a lava tube system before
breaking out onto the surface. Thermal anomalies detected by satellite

and visual observations revealed active lava flows above and on the
pali, and on the coastal plain. By 8 February, pahoehoe lava flows had
advanced 700 m from the base of the pali S onto the coastal plain.
Incandescence was sometimes seen from a vent low on the S wall of Pu'u
'O'o crater.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 29 January-5 February seismic activity from

Kliuchevskoi was above background levels and lava continued to flow
down the NW flank. Strombolian activity periodically ejected material

300 m above the crater, and phreatic explosions occurred from the

front of the lava flow. Satellite imagery revealed a large daily

thermal anomaly at the volcano. On 30 and 31 January, gas-and-steam
plumes rose to an altitude of 6.2 km (20,300 ft) a.s.l. The Level of

Concern Color Code remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 3-9

February multiple explosions from Sakura-jima produced plumes that

rose to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted SE
and N. On 5, 6, and 7 February, pilots reported that ash plumes
sometimes drifted SE and S at altitudes of 1.5-3.4 km (5,000-11,000
ft) a.s.l. An eruption on 8 February produced an estimated 1-km-high
lava fountain, and an ash plume with abundant lightning. Incandescent
material fell onto the flanks.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kago-Net

Sakura-jima Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that a thermal anomaly on Sarychev Peak was detected by
satellite on 3 February.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 29 January-5 February seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 5.7 km (18,700 ft) a.s.l. Fumarolic activity
was observed on 1 February; cloud cover prevented observations on
other days. Analyses of satellite imagery revealed a large daily

thermal anomaly from the lava dome. The Level of Concern Color Code
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 29 January-5 February activity from the

Soufrière Hills lava dome was variable as the lava dome continued to
grow. Cycles of vigorous ash venting, rockfalls, and pyroclastic flows

occurred every seven to twelve hours. Pyroclastic flows traveled
mostly W down Gages into Spring Ghaut, as far as 3 km, but also
occurred in Whites Ghaut to the NE. Rockfall activity was abundant on
the N flank. On 4 February, ash fell across NW Montserrat.
Observations the next day revealed that the central W part of the lava
dome had grown and was 1,070 m a.s.l.

Pyroclastic flows following a Vulcanian explosion on 5 February
traveled W, reaching Plymouth and spreading 500 m across the sea.
Pyroclastic flows also traveled as far as 2 km NW down Tyers Ghaut and
NE down Whites Ghaut. An ash plume rose to an altitude of 6.4 km
(21,000 ft) a.s.l. A small Vulcanian explosion on 8 February generated
pyroclastic flows that mostly traveled W down Gages Valley. Small
pyroclastic surges observed using a thermal camera descended the N
flanks. An ash plume rose to an altitude of 4.6 km (15,000 ft) a.s.l.
and drifted E and ENE. Ashfall was reported in NW Montserrat and in SW
Antigua, 50 km NW. The Hazard Level remained at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 5-6 and 9 February. Details of possible resulting
emissions were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-

jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that 14-51 explosions from Tungurahua were detected by
the seismic network during 3-9 February. Inclement weather often
prevented observations of the volcano; an ash plume was seen rising to
an altitude of 7 km (23,000 ft) a.s.l. Ashfall was noted almost daily
in areas to the SW, W, and NW, and was particularly heavy towards the
end of the reporting period. Roaring noises and sounds resembling
"cannon shots" were heard. Explosions sometimes caused windows and
structures to vibrate, including large windows at the Tungurahua
Observatory (OVT) in Guadalupe, 11 km N. Occasionally at night
incandescence emanated from the crater and incandescent blocks rolled
down the flanks as far as 1 km. On 3 February lahars descended
drainages to the W and SW, carrying tree trunks and blocks up to 1 m
in diameter, and causing the road from Riobamba to Baños to close.
Strombolian activity from the crater was seen during 6-8 February.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

http://www.igepn.edu.ec/

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

Last Post

unread,

Feb 17, 2010, 11:13:11 PM2/17/10

to aaron....@mail.mcgill.ca

SI / USGS Weekly VolcanicActivityReport

10 February- 16 February 2010

5 new + 13 Ongoing = 18 Actives

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/
usgs/

NewActivity/Unrest:

OngoingActivity:

| Bagana, Bougainville

| Chaitén, Southern Chile
| Dukono, Halmahera

| Karangetang [Api Siau], Siau I

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Nevado del Huila, Colombia
| Pacaya, Guatemala

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)
| Tungurahua, Ecuador

  This page is updated on Wednesdays, please
  see the GVP Home Page for news of the
  latest significantactivity.

The Weekly VolcanicActivityReport is a

  cooperative project between the Smithsonian's
  Global Volcanism Program and the US
  Geological Survey'sVolcanoHazards Program.

Updated by 2300 UTC every Wednesday,

notices of volcanicactivityposted on these pages

are preliminary and subject to change as events
are studied in more detail.
This is not a comprehensive list of all of Earth's
volcanos erupting during the week, but rather a

summary ofactivityat volcanoes that meet

  criteria discussed in detail in the "Criteria and
  Disclaimers" section. Carefully reviewed,
  detailed reports on various volcanoes are
  published monthly in the Bulletin of the Global
  Volcanism Network.

  Note: Many news agencies do not archive the
  articles they post on the Internet, and therefore
  the links to some sources may not be active. To
  obtain information about the cited articles that
  are no longer available on the Internet contact
  the source.

NewActivity/Unrest

BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit
elev. 2882 m

KVERT reported that during 5-12 February a thermal anomaly from
Bezymianny's lava dome was detected in satellite imagery. On 6
February a new hot lava flow from the lava dome was observed.
Fumarolic activity was observed on 7 and 9 February. The Aviation
Color Code level was lowered to Yellow.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny
volcano had been considered extinct. Three periods of intensified
activity have occurred during the past 3,000 years. The latest period,
which was preceded by a 1,000-year quiescence, began with the dramatic
1955-56 eruption. That eruption, similar to the 1980 event at Mount
St. Helens, produced a large horseshoe-shaped crater that was formed
by collapse of the summit and an associated lateral blast. Subsequent
episodic but ongoing lava-dome growth, accompanied by intermittent
explosive activity and pyroclastic flows, has largely filled the 1956
crater.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bezymianny Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

Cameras operated by OVDAS-SERNAGEOMIN showed steam-and-gas plumes
rising from Llaima's main crater during 20 January-9 February. Seismic
signals (tremor and volcano-tectonic earthquakes) had characteristics
that indicated fluid movement within the volcano's conduits. The Alert
Level was raised to Yellow, Level 3. SERNAGEOMIN recommended that
people stay at least 4 km away from the main crater.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 5-12 February activity from the Soufrière
Hills lava dome increased significantly. Activity was concentrated on
the W side of the lava dome during the first part of the week then
shifted to the N side on 9 February.

On 11 February part of the lava dome collapsed leaving a large
collapse scar on the NE flank. Pyroclastic flows traveled NE and then,
along with pyroclastic surges, across the sea at several places on the
E side of Montserrat. Pyroclastic flow deposits covered several
hundred meters of the coastline near the old Bramble airport, about 5
km NE. Pyroclastic flows also traveled NW into Tyers Ghaut and down
the Belham valley as far a Cork Hill, 4 km NW. An ash plume rose to an
altitude of 15.2 km (50,000 ft) a.s.l. and drifted E and then SE.
Ashfall occurred in NE Montserrat, SW Antigua (50 km NW), Guadeloupe
(65 km SE), and Dominica (145 km SE). According to news articles,
flights in and out of the region were temporarily suspended due to the
ash plumes.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Sources: Montserrat Volcano Observatory (MVO), Agence France-Presse

Soufrière Hills Information from the Global Volcanism Program

TIATIA Kunashir Island 44.351°N, 146.256°E; summit elev. 1819 m

SVERT reported that a weak thermal anomaly from Tiatia was detected by
satellite on 9 February.

Geologic Summary. Tiatia volcano, one of the most impressive of the
Kuril Islands, consists of a beautifully symmetrical cone that rises
above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide
caldera. The 1819-m-high Tiatia (also known as Chacha-dake) occupies
the NE tip of Kunashir Island and morphologically resembles Mount
Vesuvius. The pristine-looking conical central cone, mostly formed by
basaltic to basaltic-andesite strombolian eruptions, rises 400 m above
the floor of the caldera and contains a 400 x 250 m wide crater with
two explosion vents separated by a linear septum. Fresh lava flows
cover much of the SW caldera floor and have overflowed the rim,
extending to the foot of the older somma, which formed during the late
Pleistocene or early Holocene. A lava flow from a flank cone on the
northern caldera rim reached the Sea of Okhotsk. A major explosive
eruption in 1973 was the first since Tiatia's initial historical
eruption in 1812.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Tiatia Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 14-15 February ash plumes from Ulawun drifted 45-95 km at
altitudes of 2.4-3.7 km (8,000-12,000 ft) a.s.l.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 11-15 February ash plumes from Bagana rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 20-150 km E and NE.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

On 11 February, ODVAS-SERNAGEOMIN reported that a camera, installed
800 m from the center of Chaitén's lava-dome complex in late January,
showed incandescence and gas emissions on 28 January. Seismicity had
also increased during 21 January-3 February. The Alert Level remained
at Red. Based on web camera views and analyses of satellite imagery,
the Buenos Aires VAAC reported that a steam-and-gas plume drifted 25
km NW on 11 February at an altitude of 2.4 km (8,000 ft) a.s.l.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 10 February a plume from Dukono was
seen on satellite imagery drifting 150 km SW at an altitude of 2.4 km
(8,000 ft) a.s.l.

Geologic Summary. Reports from this remote volcano in northernmost

Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m

On 12 February, CVGHM reported that seismicity from Karangetang
declined during 1 January-8 February. When the weather was clear,
white plumes were seen rising 100-200 m above the crater rim.
Incandescent material was ejected 10-50 m above the Utama Crater.
Based on these observations and the decline in seismicity, CVGHM
lowered the Alert level to 2 (on a scale of 1-4).

Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi, and contains five
summit craters strung along a N-S line. One of Indonesia's most active
volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Karangetang [Api Siau] Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 5-12 February seismic activity from

Karymsky was above background levels and possibly indicated weak ash
explosions. Analyses of satellite imagery revealed a thermal anomaly

over the volcano on 8 February; meteorological clouds prevented
observations on other days. The Aviation Color Code level remained at
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 10-16 February, HVO reported an active lava surface about 200 m

below a vent in the floor of Kilauea's Halema'uma'u crater. The lava
surface occasionally spattered, and both rose and drained through
holes in the cavity floor. A plume from the vent drifted mainly SW,
dropping small amounts of ash, and occasionally fresh spatter,

downwind. Measurements on 11 February indicated that the sulfur
dioxide emission rate at the summit remained elevated at 900 tonnes
per day. The 2003-2007 average rate was 140 tonnes per day. That same
day a significant rockfall or collapse event was followed by a brown
plume for several minutes.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless
shield complex flowed over 3 km SE through a lava tube system before
breaking out onto the surface. Thermal anomalies detected by satellite

and visual observations revealed active lava flows on the pali and on
the coastal plain. Incandescence was sometimes seen from a vent low on

the S wall of Pu'u 'O'o crater.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 5-12 February seismic activity from

Kliuchevskoi was above background levels and lava continued to flow
down the NW flank. Strombolian activity periodically ejected material

300 m above the crater. Steam plumes rose to an altitude of 6 km
(19,700 ft) a.s.l. on 8, 9, and 10 February, and were seen on
satellite imagery drifting 65 km NE. Satellite imagery also revealed a
large daily thermal anomaly at the volcano. The Aviation Color Code
level remained at Orange. Based on information from KVERT and analyses
of satellite imagery, the Tokyo VAAC reported that on 13 February an
ash plume rose to an altitude of 6.4 km (21,000 ft) a.s.l. and drifted
NW.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that during 10-16 February whitish gas plumes from
Nevado del Huila were seen through the web camera rising no more than
2 km above the lava domes. The rate of sulfur dioxide emissions was
945 and 4,130 tonnes per day on 10 and 16 February, respectively.
During an overflight on 12 February scientists saw gas emissions and
thermal anomalies on the high part of the dome. Based on analyses of
images, the volume of the extruded lava dome was an estimated 70
million cubic meters. The Alert Level remained at III (Yellow;

"changes in the behavior of volcanic activity").

Geologic Summary. Nevado del Huila, the highest active volcano in

Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Huila Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 10 February, INSIVUMEH reported that lava flows from Pacaya,
descending the flanks since April 2006, continued to flow down the E
flank onto part of the meseta. During 11-16 February, lava flows
100-400 m long descended the E and NE flanks. Avalanches of blocks
from the lava-flow fronts set fire to local vegetation.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during

11-16 February multiple explosions from Sakura-jima produced plumes

that rose to altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and

drifted N, E, SE, and S.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 5-12 February seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 5.2 km (17,100 ft) a.s.l. Fumarolic activity
was occasionally observed. Analyses of satellite imagery revealed a
large daily thermal anomaly from the lava dome. The Aviation Color
Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 11-16 February. Details of possible resulting
plumes were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 10-16 February explosions from Tungurahua
were detected by the seismic network. The explosions often produced
sounds resembling "cannon shots" and caused windows and structures to
occasionally vibrate. Blocks ejected from the crater fell onto the
flanks and rolled as far as 2 km from the crater. Ash plumes rose to
altitudes of 5.5-9 km (18,000-29,500 ft) a.s.l. On 11 February, a
small pyroclastic flow seen from Tungurahua Observatory (OVT) in
Guadalupe, 11 km N, descended the N and NNW flanks. Ashfall was seen
daily and impacted areas to the NW, W, SW, and S. Ashfall was 3 mm
thick in Choglontus, Cahuají, and Pillate on 12 February, and 1 mm
thick in Choglontus on 14 February.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

leona...@gmail.com

unread,

Feb 24, 2010, 11:56:51 PM2/24/10

to aaron....@mail.mcgill.ca, leona...@gmail.com

SI / USGS Weekly VolcanicActivityReport

17 February- 23 February 2010

5 new + 13 Ongoing = 18 Actives

Sally Kuhn Sennert - Weekly Report
Editor
http://www.volcano.si.edu/reports/
usgs/

New Activity/Unrest:

| Ol Doinyo Lengai, Tanzania

| Reventador, Ecuador
| Soufrière Hills, Montserrat

| Ulawun, New Britain

Ongoing Activity:

| Bagana, Bougainville

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Sakura-jima, Kyushu
| Sangay, Ecuador

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)

| Talang, Sumatra (Indonesia)
| Tungurahua, Ecuador

NewActivity/Unrest

OL DOINYO LENGAI Tanzania 2.764°S, 35.914°E; summit elev. 2962 m

According to Frederick Belton's website, geologists that had climbed
Ol Doinyo Lengai on 11 February saw periodic eruptions from a small
fissure, and steam emissions from an area of the crater rim next to a
part that had collapsed. Another group of geologists that visited
during 14-15 February noted three new hornitos on the W part of the
crater floor that were black and very fresh. They also noted a cone-
shaped gray hornito on the middle of the floor and a new black lava
flow to the S.

Geologic Summary. The symmetrical Ol Doinyo Lengai stratovolcano is
the only volcano known to have erupted carbonatite tephras and lavas
in historical time. The prominent volcano, known as "The Mountain of
God," rises abruptly above the broad plain S of Lake Natron. The cone-
building stage of the volcano ended about 15,000 years ago and was
followed by periodic ejection of natrocarbonatite and nephelinite
tephra during the Holocene. Historical eruptions have consisted of
smaller tephra eruptions and emission of numerous natrocarbonatitic
lava flows on the floor of the summit crater. Petrologists first
observed the eruption of carbonatitic lava flows in the 1960s.
Subsequent more frequent visits have documented long-term lava
effusion in the summit crater that would not have been seen from the
foot of the volcano.

Map

Source: Frederick Belton's Ol Doinyo Lengai website

Ol Doinyo Lengai Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The MODIS satellite detected a thermal anomaly over Reventador on 14
February. Based on information from the Guayaquil MWO, the Washington
VAAC reported an ash emission on 18 February. Ash was not identified
in satellite imagery. IG reported that seismic signals indicated an
emission that day, but weather conditions prevented visual
observations.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),

Hawai'i Institute of Geophysics and Planetology (HIGP) Moderate

Resolution imaging Spectroradiometer (MODIS) Thermal Alert System,
Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 12-19 February activity from the Soufrière
Hills lava dome was at a low level. Rockfalls originated from the
inner walls of the 300-m-wide collapse scar on the N flank, formed
from the 11 February event, and from the dome summit. Gas measurements
on 17 February and seismicity were consistent with lava-dome growth,
but growth was unconfirmed.

Inspection of the deposits from the 11 February collapse event
revealed that the NE coastline had extended into the sea an additional
650 m. Pyroclastic flows razed many buildings in both Harris (3 km N)
and Streatham (2 km NNW), and destroyed trees in the Gun Hill area (2
km NNW). Pyroclastic-flow deposits were approximately 15 m thick in
the Trants region of the coast (near the old Bramble airport, about 5
km NE). A deep crater, similar in diameter to the collapse scar, was
seen in the summit of the lava dome. The Hazard Level remained at 4.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that during 12-20 February Ulawun emitted white vapor
that was occasionally forceful. A plume seen on satellite imagery on
14 February drifted NNE.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

RVO reported that white vapor from Bagana was emitted during 1-21
February. Ash plumes were seen on 5 February and night-time
incandescence was seen on 2, 12, 13, and 19 February. Sulfur dioxide
plumes drifted ENE during 11-20 February and NNW on 20 and 21
February.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Rabaul Volcano Observatory (RVO)

Bagana Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity from Karymsky was above
background levels during 11-14 February, possibly indicating weak ash

explosions. Analyses of satellite imagery revealed a thermal anomaly

over the volcano during that time and also on 15 February. Seismic
activity was at background levels during 15-19 February. The Aviation

Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 17-23 February, HVO reported an active lava surface about 200 m

below a vent in the floor of Kilauea's Halema'uma'u crater. The lava

surface circulated and occasionally spattered, and both rose and
drained through holes in the cavity floor. Bursting bubbles and low
lava fountains were also noted. A plume from the vent drifted mainly
SW, dropping small amounts of ash downwind. Measurements on 18

February indicated that the sulfur dioxide emission rate at the summit

remained elevated at 600 tonnes per day. The 2003-2007 average rate

was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless

shield complex flowed over 3 km SE through a lava tube system before
breaking out onto the surface. Thermal anomalies detected by satellite

and visual observations revealed active lava flows on the W side of
the TEB flow field, on the pali, and on the coastal plain.

Incandescence was sometimes seen from a vent low on the S wall of Pu'u
'O'o crater.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 12-19 February seismic activity from

Kliuchevskoi was above background levels and lava continued to flow
down the NW flank. Strombolian activity periodically ejected material

200 m above the crater, and phreatic explosions occurred from the
front of the lava flow. Satellite imagery revealed a large daily
thermal anomaly at the volcano and gas-and-steam plumes that drifted
over 240 km NE. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

The Tokyo VAAC reported that during 17-23 February plumes from Sakura-
jima identified on satellite imagery, and ash plumes seen by pilots,
rose to altitudes of 1.5-4 km (5,000-13,000 ft) a.s.l. and drifted NE,
E, SE, and S.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on pilot observations, the Washington VAAC reported that on 22
February an ash plume from Sangay rose to an altitude of 7.6 km
(25,000 ft) a.s.l. Ash was not identified in satellite imagery.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 12-19 February seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 5.1 km (16,700 ft) a.s.l. Fumarolic activity

was occasionally observed. Analyses of satellite imagery revealed a

large daily thermal anomaly from the lava dome and ash plumes that
drifted over 70 km in northern directions on 11, 13, and 17 February.
The Aviation Color Code level remained at Orange. Based on information
from KVERT, the Tokyo VAAC reported that on 23 February an eruption
produced a plume that rose to an altitude of 3 km (10,000 ft) a.s.l.
and drifted N.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 17-19 and 21-22 February. Plumes occasionally
rose to altitudes of 1.2-1.8 km (4,000-6,000 ft) a.s.l. and drifted E
and SE.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TALANG Sumatra (Indonesia) 0.978°S, 100.679°E; summit elev. 2597 m

On 17 February, CVGHM lowered the Alert Level for Talang from 3 to 2
(on a scale of 1-4) because seismicity had declined in general since
February 2009. Visitors and tourists were advised not approach the
crater.

Geologic Summary. Talang, which forms a twin volcano with the extinct
Pasar Arbaa volcano, has two crater lakes on its flanks. The largest
of these is 1 x 2 km wide Danau Talang. No historical eruptions have
occurred from the summit of the volcano, which lacks a crater. All
historical eruptions from Gunung Talang volcano have involved small-to-
moderate 19th-century explosive activity originating from a series of
small craters in a valley on the upper NE flank.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Talang Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that explosions from Tungurahua were detected by the
seismic network during 16-23 February. Although inclement weather
often prevented observations of the volcano, ash plumes were seen
rising to altitudes of 6-8 km (19,700-26,200 ft) a.s.l. and drifting
S, SW, W, and ENE. Ashfall was noted almost daily, in areas to the SW
and S. Blocks rolled down the flanks on 18 February. Lahars descended
NW and W drainages on 20 February and a SW drainage on 22 February. On
21 February small block avalanches on the N flank generated
pyroclastic flows.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

Global Volcanism Program — Department of Mineral Sciences
National Museum of Natural History — Smithsonian Institution

>

> a small lava dome in ...
>
> read more »

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SI / USGS Weekly VolcanicActivityReport

17 February- 23 February 2010

4 new + 10 Ongoing = 14 Actives

New Activity/Unrest:

Ongoing Activity:

NewActivity/Unrest

Map

Ongoing Activity

Map

within a 5-km-wide caldera that ...

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SI / USGS Weekly VolcanicActivityReport

24 February-2 March 2010

3 new + 11 Ongoing = 14 Actives

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/usgs/

NewActivity/Unrest:

| Poás, Costa Rica
| Semeru, Eastern Java (Indonesia)
| Soufrière Hills, Montserrat

Ongoing Activity:

| Fuego, Guatemala

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Mayon, Luzon
| Pacaya, Guatemala
| Popocatépetl, México

| Sakura-jima, Kyushu
| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Tungurahua, Ecuador

New Activity/Unrest

POAS Costa Rica 10.20°N, 84.233°W; summit elev. 2708 m

OVSICORI-UNA reported that on 23 February a phreatic eruption from
Laguna Caliente, a summit lake of Poás, ejected gray and sulfur-
scented sediment onto the southern flanks. The event was seen by a
scientist collecting samples in the low part of the crater and by
visitors at the viewpoint area. Seismographs showed no precursory
signals.

Geologic Summary. The broad, well-vegetated edifice of Poás, one of
the most active volcanoes of Costa Rica, contains three craters along
a N-S line. The frequently visited multi-hued summit crater lakes of
the basaltic-to-dacitic volcano, which is one of Costa Rica's most
prominent natural landmarks, are easily accessible by vehicle from the
nearby capital city of San José. A N-S-trending fissure cutting the
2,708-m-high complex stratovolcano extends to the lower northern
flank, where it has produced the Congo stratovolcano and several lake-
filled maars. The southernmost of the two summit crater lakes, Botos,
is cold and clear and last erupted about 7,500 years ago. The more
prominent geothermally heated northern lake, Laguna Caliente, is one
of the world's most acidic natural lakes, with a pH of near zero. It
has been the site of frequent phreatic and phreatomagmatic eruptions
since the first historical eruption was reported in 1828. Poás
eruptions often include geyser-like ejection of crater-lake water.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Poás Information from the Global Volcanism Program

SEMERU Eastern Java (Indonesia) 8.108°S, 112.92°E; summit elev. 3676 m

On 1 March, CVGHM reported that although inclement weather often
prevented observations of Semeru during November 2009-February 2010,
"smoke" was often seen rising 50-500 m above the Jonggring Seloko
crater. During 25-28 February, incandescent rock avalanches traveled
as far as 750 m from the crater. The Alert Level remained at 2 (on a
scale of 1-4).

Geologic Summary. Semeru is the highest volcano on Java and one of its
most active. The symmetrical stratovolcano rises abruptly to 3,676 m
above coastal plains to the S and lies at the southern end of a
volcanic massif extending N to the Tengger caldera. Semeru has been in
almost continuous eruption since 1967. Frequent small-to-moderate
Vulcanian eruptions have accompanied intermittent lava dome extrusion,
and periodic pyroclastic flows and lahars have damaged villages below
the volcano. A major secondary lahar on 14 May 1981 caused more than
250 deaths and damaged 16 villages.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Semeru Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 19-26 February activity from the Soufrière
Hills lava dome was at a low level. A few rockfalls originated from
the inner walls of the collapse scar on the N flank, formed during the
11 February event. Small areas of incandescence on the dome were
noted. Gas emission ratios were consistent with slow lava extrusion,
but growth was unconfirmed. On 26 February scientists first saw the
crater at the summit of the lava dome formed by explosions on 11
February. The crater was 200 m in diameter and 50-100 m deep. The
Hazard Level was lowered to 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

Ongoing Activity

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 26 February and 2 March, INSIVUMEH reported that explosions from
Fuego produced gray plumes that rose to altitudes of 4.1-4.5 km
(13,500-14,800 ft) a.s.l. and drifted E and NE. Avalanches descended
the S and W flanks. Weak incandescence emanated from the crater. On 2
March, ash fell in areas downwind.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity from Karymsky was occasionally
above background levels during 19-26 February, possibly indicating
weak ash explosions. Analyses of satellite imagery revealed a weak
thermal anomaly over the volcano on 22 and 24 February; cloud cover
prevented observations on other days. The Aviation Color Code level
was lowered to Yellow.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed

within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 24 February-2 March, HVO reported an active lava surface about

200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The

lava surface circulated and both rose and drained through holes in the
cavity floor. Low lava fountains rose from the south edge of the deep
pit. A plume from the vent drifted mainly SW, dropping small amounts
of ash downwind. Measurements on 25 February indicated that the sulfur
dioxide emission rate at the summit remained elevated at 900 tonnes

per day. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless

shield complex flowed SE through a lava tube system and broke out onto

the surface. Thermal anomalies detected by satellite and visual

observations revealed active lava flows on the pali and on the coastal

plain. Incandescence was sometimes seen from a vent low on the S wall
of Pu'u 'O'o crater.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 19-26 February seismic activity from

Kliuchevskoi was above background levels and lava continued to flow
down the NW flank. Strombolian activity periodically ejected material

300 m above the crater, and phreatic explosions occurred from the
fronts of the lava flows. Satellite imagery revealed a large daily

thermal anomaly at the volcano and gas-and-steam plumes that drifted

90 km NNW on 23 February and 25 km ESE the next day. The Aviation

Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active

volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

On 2 March, PHIVOLCS reported that, after the Alert Level for Mayon
was lowered to 2 on 13 January, seismicity remained at normal levels,
deflation was measured, and sulfur dioxide emissions were consistent
with post-eruption levels. Rising steam and incandescence from the
crater was not indicative of any new activity. The Alert level was
lowered to 1 and the public was reminded not to enter the 6-km-radius
Permanent Danger Zone (PDZ).

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of

people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Mayon Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that on 26 February explosions from Pacaya ejected
tephra 150 m high. Bluish-white plumes drifted N and a lava flow
traveled 800 m E.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported emissions of steam and gas from Popocatépetl during
24-28 February. Plumes contained small amounts of ash on 28 February
and 1 March.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

The Tokyo VAAC reported that during 24 February-2 March explosions
from Sakura-jima produced plumes identified in satellite imagery and
seen by pilots. The plumes, occasionally containing ash, rose to
altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted N, NE, E,
and SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 2 March, INSIVUMEH reported that explosions from Santa María's
Santiaguito lava dome complex produced ash plumes that rose to
altitudes of 2.8-3.1 km (9,200-10,200 ft) a.s.l. and drifted E and NE.
Ash fell in areas downwind.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 19-26 February seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 5 km (16,400 ft) a.s.l. Fumarolic activity
was occasionally observed. Ash and snow fell simultaneously in
Klyuchi, 50 km SW, on 21 February. Analyses of satellite imagery
revealed a large daily thermal anomaly from the lava dome, and ash
plumes that drifted 30 km to the N and E on 23 and 25 February,
respectively. Gas-and-steam plumes drifted 60 km N during 18 and 22-25
February. The Aviation Color Code level remained at Orange. Based on
information from KVERT, the Tokyo VAAC reported that on 26 February an
ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted
NE.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

During 24-28 February, IG reported that as many as 11 explosions from
Tungurahua were detected by the seismic network; explosions were not
detected on 1 or 2 March. Although inclement weather occasionally
prevented observations of the volcano, ash plumes were seen during 24
February-1 March rising to altitudes of 6.5-8 km (21,300-26,200 ft)
a.s.l. and drifting SW and W. Ashfall was noted almost daily in areas
downwind.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of

Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

leona...@gmail.com

unread,

Mar 11, 2010, 9:44:07 PM3/11/10

to

SI / USGS Weekly VolcanicActivityReport

3 March - 9 March 2010

2 new + 10 Ongoing = 12 Actives

Sally Kuhn Sennert - Weekly Report Editor
http://www.volcano.si.edu/reports/
usgs/

NewActivity/Unrest:

| Concepción, Nicaragua
| Llaima, Central Chile

Ongoing Activity:

| Ambrym, Vanuatu (SW Pacific)
| Arenal, Costa Rica

| Batu Tara, Komba Island (Indonesia)

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Sakura-jima, Kyushu
| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Soufrière Hills, Montserrat
| Tungurahua, Ecuador

NewActivity/Unrest

CONCEPCION Nicaragua 11.538°N, 85.622°W; summit elev. 1700? m

Based on information from INETER and analyses of satellite imagery,
the Washington VAAC reported that on 8 March an ash plume from
Concepción rose to an estimated altitude of 2.1 km (7,000 ft) a.s.l.
The plume was last seen in satellite imagery later that day 227 km W.

Geologic Summary. Volcán Concepción is one of Nicaragua's highest
volcanoes and is also one of its most active. The symmetrical volcano
forms the NW half of the dumbbell-shaped island of Ometepe in Lake
Nicaragua. Concepción is connected to neighboring Madera volcano by a
narrow isthmus. N-S-trending fractures cutting across the volcano are
associated with spatter cones, cinder cones, and maars located on the
middle N flank and on the lower S flank down to Lake Nicaragua.
Concepción has had frequent moderate explosive eruptions in the past
century, most of which have originated from a small summit crater.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Concepción Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

SERNAGEOMIN reported that on 4 March seismicity from Llaima increased.
During an overflight that same day, scientists observed emissions of
gas and steam from the main crater. Images taken that day were
compared to those taken on 21 February and showed no significant
changes in morphology. The rate of sulfur dioxide emissions had
increased, however. Scientists also noted deposits from a large
rockfall along with fracturing of the glacier, especially on the upper
N and NW flanks. Those observations in addition to the increased
seismicity prompted SERNAGEOMIN to raise the Alert Level to Yellow,
Level 4.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

Ongoing Activity

AMBRYM Vanuatu (SW Pacific) 16.25°S, 168.12°E; summit elev. 1334 m

Based on pilot observations and analyses of satellite imagery, the
Wellington VAAC reported that ash plumes from Ambrym rose to an
altitude of 2.4 km (8,000 ft) a.s.l. on 5 March.

Geologic Summary. Ambrym, a large basaltic volcano with a 12-km-wide
caldera, is one of the most active volcanoes of the New Hebrides arc.
A thick, almost exclusively pyroclastic sequence, initially dacitic,
then basaltic, overlies lava flows of a pre-caldera shield volcano.
The caldera was formed during a major Plinian eruption with dacitic
pyroclastic flows about 1900 years ago. Post-caldera eruptions,
primarily from Marum and Benbow cones, have partially filled the
caldera floor and produced lava flows that ponded on the caldera floor
or overflowed through gaps in the caldera rim. Post-caldera eruptions
have also formed a series of scoria cones and maars along a fissure
system oriented ENE-WSW. Eruptions have apparently occurred almost
yearly during historical time from cones within the caldera or from
flank vents. However, from 1850 to 1950, reporting was mostly limited
to extra-caldera eruptions that would have affected local populations.

Map

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Ambrym Information from the Global Volcanism Program

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during February activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian

eruptions, and occasional avalanches. A lava flow traveled down the SW
flank. Acid rain and small amounts of ejected pyroclastic material
affected the NE and SE flanks. Avalanches from the crater and from
lava-flow fronts traveled down the SW, S, and SE flanks, occasionally
igniting vegetation. Crater D produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.

748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 8-9 March ash plumes from Batu Tara rose to altitudes of
1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted 45-120 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 3-9 March, HVO reported an active lava surface about 200 m

below a vent in the floor of Kilauea's Halema'uma'u crater. The lava

surface circulated and both rose and drained through a pit in the
cavity floor. A plume from the vent drifted mainly SW, dropping small
amounts of ash downwind. Measurements during 4-5 March indicated that

the sulfur dioxide emission rate at the summit remained elevated at

700-800 tonnes per day. The 2003-2007 average rate was 140 tonnes per
day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless

shield complex flowed SE through the upper portion of a lava tube

system and broke out onto the surface. Thermal anomalies detected by

satellite, and visual observations, revealed active lava flows on the

pali and on the coastal plain.

Geologic Summary. Kilauea, one of five coalescing volcanoes that

comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 26 February-5 March seismic activity from

Kliuchevskoi was above background levels and lava continued to flow
down the NW flank. Strombolian activity periodically ejected material
300 m above the crater, and phreatic explosions occurred from the

fronts of the lava flows. Steam-and-gas plumes rose to an altitude of
6.8 km (22,300 ft) a.s.l. most days, and on 3 March one drifted 50 km
NE. Satellite imagery revealed a large daily thermal anomaly from the
volcano. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

During 3-9 March, the Tokyo VAAC reported multiple explosions from
Sakura-jima based on information from JMA. During 3, 5-6, and 8-9
March, plumes rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l.
and drifted NE, E, and SE. Pilots reported on 8 and 9 March that ash
plumes rose as high as 3 km (10,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 4 March, INSIVUMEH reported that explosions from Santa María's

Santiaguito lava dome complex produced ash plumes that rose to

altitudes of 2.7-3 km (8,900-10,000 ft) a.s.l. and drifted E. Ash fell
in inhabited areas downwind. The Washington VAAC reported that on 8
March an ash plume was seen in satellite imagery drifting WNW.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 26 February-5 March seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 6 km (19,700 ft) a.s.l. Fumarolic activity
was occasionally observed. Analyses of satellite imagery revealed a

large daily thermal anomaly from the lava dome, and ash plumes that

drifted 30 km NE on 26 February and 130 km SE on 28 February. Ash fell
in Klyuchi, 50 km SW, on 26 February. On 3 March, a second thermal
anomaly on the S flank was noted. Based on information from KVERT and
analyses of satellite imagery, the Tokyo VAAC reported that during 5
and 8-9 March ash plumes rose to an altitude of 2.7 km (9,000 ft)
a.s.l. and drifted E and SE. The Aviation Color Code level remained at
Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 26 February-5 March activity from the
Soufrière Hills lava dome was at a low level. A swarm of seven
relatively large hybrid earthquakes was detected early on 4 March.
Later that morning, two small pyroclastic flows descended the Tar
River valley and caused ashfall in Salem and Olveston, 6-8 km NW. The
Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that on 2 March an ash plume from Tungurahua rose to
an altitude of 8.5 km (28,000 ft) a.s.l. and drifted NW. Although
inclement weather often prevented observations of the volcano during
3-9 March, fumarolic activity in the crater was seen on 6 and 8 March.
Ash fell in areas to the SW on 3 and 4 March.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

leona...@gmail.com

unread,

Mar 17, 2010, 5:47:43 PM3/17/10

to

SI / USGS Weekly VolcanicActivityReport

10 March-16 March 2010

5 new + 11 Ongoing = 16 Actives

Sally Kuhn Sennert - Weekly Report Editor

NewActivity/Unrest:

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile
| Dukono, Halmahera

| Karymsky, Eastern Kamchatka

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)
| Sakura-jima, Kyushu

| Sarychev Peak, Matua Island

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Tungurahua, Ecuador

       This page is updated on Wednesdays, please
       see the GVP Home Page for news of the
       latest significantactivity.

       The Weekly VolcanicActivityReport is a
       cooperative project between the Smithsonian's
       Global Volcanism Program and the US
       Geological Survey'sVolcanoHazards Program.

      Updated by 2300 UTC every Wednesday,
       notices of volcanicactivityposted on these pages
      are preliminary and subject to change as events
       are studied in more detail.
      This is not a comprehensive list of all of Earth's
       volcanos erupting during the week, but rather a

summary of activity at volcanoes that meet

       criteria discussed in detail in the "Criteria and
       Disclaimers" section. Carefully reviewed,
      detailed reports on various volcanoes are
       published monthly in the Bulletin of the Global
       Volcanism Network.

       Note: Many news agencies do not archive the
       articles they post on the Internet, and therefore
       the links to some sources may not be active. To
       obtain information about the cited articles that
       are no longer available on the Internet contact
      the source.

NewActivity/Unrest

CONCEPCION Nicaragua 11.538°N, 85.622°W; summit elev. 1700? m

According to the Washington VAAC, INETER reported an eruption from
Concepción on 12 March. A rapidly-dissipating ash cloud was seen on
satellite imagery almost 60 km E of the summit.

Geologic Summary. Volcán Concepción is one of Nicaragua's highest
volcanoes and is also one of its most active. The symmetrical volcano
forms the NW half of the dumbbell-shaped island of Ometepe in Lake
Nicaragua. Concepción is connected to neighboring Madera volcano by a
narrow isthmus. N-S-trending fractures cutting across the volcano are
associated with spatter cones, cinder cones, and maars located on the
middle N flank and on the lower S flank down to Lake Nicaragua.
Concepción has had frequent moderate explosive eruptions in the past
century, most of which have originated from a small summit crater.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Concepción Information from the Global Volcanism Program

STROMBOLI Aeolian Islands (Italy) 38.789°N, 15.213°E; summit elev. 924
m

INGV-CT reported strong explosions from Stromboli on 10 March mainly
from craters located in the N part of the crater terrace, a flat area
in the upper part of Sciara del Fuoco (a depression cutting the NW
flank of the volcano). After one of the more powerful explosions, lava
flowed over the NW edge of the crater terrace for tens of meters
before fragmenting and producing small landslides of hot material that
likely reached the sea.

Geologic Summary. Spectacular incandescent nighttime explosions at
Stromboli volcano have long attracted visitors to the "Lighthouse of
the Mediterranean."Stromboli, the NE-most of the Aeolian Islands, has
lent its name to the frequent mild explosive activity that has
characterized its eruptions throughout historical time. The small, 926-
m-high island of Stromboli is the emergent summit of a volcano that
grew in two main eruptive cycles, the last of which formed the western
portion of the island. The active summit vents are located at the head
of the Sciara del Fuoco, a horseshoe-shaped scarp formed as a result
of slope failure that extends to below sea level and funnels
pyroclastic ejecta and lava flows to the NW. Essentially continuous
mild Strombolian explosions, sometimes accompanied by lava flows, have
been recorded at Stromboli since Roman times.

Map

Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di
Catania (INGV-CT)

Stromboli Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

OVSICORI-UNA reported that scientists visited Turrialba at night on 7
March. A gas plume, commonly seen drifting with prevailing winds, was
seen that night rising 1.5 km above the crater and drifting NW. Noises
from the crater were described as sounding like a jet engine and
rumblings. A vent, formed in January, emitted gas at temperatures
between 300 and 320 degrees Celsius. Small blocks 3-12 cm in diameter
and different colors dominated the surface around the vent. Lithics
ejected 30-50 m away from the vent measured 170 degrees Celsius.
Incandescence seen at night originated from the vent which ejected
reddish-colored tephra.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Observatorio Vulcanológico y Sismológico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Turrialba Information from the Global Volcanism Program

VILLARRICA Central Chile 39.42°S, 71.93°W; summit elev. 2847 m

Based on web camera views, the Buenos Aires VAAC indicated that on 11
March a diffuse gas-and-ash plume from Villarrica drifted near the
crater. Ash was not detected on satellite imagery. That same day,
SERNAGEOMIN reported that, during an overflight, scientists saw a
typical-looking gas plume drifting SW and tephra deposits on the
flanks.

Geologic Summary. Villarrica, one of Chile's most active volcanoes,
rises above the lake and town of the same name. It is the westernmost
of three large stratovolcanoes that trend perpendicular to the Andean
chain. A 6-km wide caldera formed during the late Pleistocene, more
than 0.9 million years ago. A 2-km-wide postglacial caldera is located
at the base of the presently active, dominantly basaltic-to-andesitic
cone at the NW margin of the Pleistocene caldera. About 25 scoria
cones dot Villarrica's flanks. Plinian eruptions and pyroclastic flows
have been produced during the Holocene from this dominantly basaltic
volcano, but historical eruptions have consisted largely of mild-to-
moderate explosive activity with occasional lava effusion. Lahars from
the glacier-covered volcano have damaged towns on its flanks.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos
Aires Volcanic Ash Advisory Center (VAAC)

Villarrica Information from the Global Volcanism Program

YASUR Vanuatu (SW Pacific) 19.53°S, 169.442°E; summit elev. 361 m

On 12 March, Vanuatu Geohazards Observatory reported that thermal
anomalies from Yasur were detected in satellite imagery during 8
December 2009-8 March 2010. They also noted an increase in activity
since January 2010. Satellite images from 21 January showed
significant sulfur dioxide gas emissions. Bombs were ejected sometime
during the week of 1 March. Observations on 8 March and analyses of
seismic data also indicated increased activity, and all three vents
were active. The Vanuatu Volcano Alert Level (VVAL) was raised to 2
(on a scale of 0-4).

Geologic Summary. Yasur, the best-known and most frequently visited of
the Vanuatu volcanoes, has been in more-or-less continuous Strombolian
and vulcanian activity since Captain Cook observed ash eruptions in
1774. This style of activity may have continued for the past 800
years. Yasur is a mostly unvegetated pyroclastic cone with a nearly
circular, 400-m-wide summit crater. Yasur is largely contained within
the small Yenkahe caldera in SE Tanna Island. It is the youngest of a
group of Holocene volcanic centers constructed over the down-dropped
NE flank of the Pleistocene Tukosmeru volcano. Active tectonism along
the Yenkahe horst accompanying eruptions of Yasur has raised Port
Resolution harbor more than 20 m during the past century.

Map

Source: Vanuatu Geohazards Observatory

Yasur Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 10-16 March ash plumes from Batu Tara rose to altitudes of
2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted about 20-150 km N, NW,
W, SW, and SSE.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the
Buenos Aires VAAC reported that a diffuse ash plume from Chaitén's
lava-dome complex, likely mixed with steam and gas, drifted NE on 15
March.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 13 March an ash plume from Dukono was
seen on satellite imagery drifting 75 km E at an altitude of 2.7 km
(9,000 ft) a.s.l.

Geologic Summary. Reports from this remote volcano in northernmost

Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 5-12 March seismic activity from Karymsky
was slightly above background levels, possibly indicating weak ash
explosions. A weak daily thermal anomaly was detected in satellite
imagery. Based on information from KEMSD, the Tokyo VAAC reported that
an eruption on 12 March produced a plume that rose to an altitude of
5.8 km (19,000 ft) a.s.l. Ash was not identified on satellite imagery.
The Level of Aviation Color Code remained at Yellow.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 10-16 March, HVO reported incandescence from an active lava

surface about 200 m below a vent in the floor of Kilauea's
Halema'uma'u crater. The lava surface circulated and both rose and

drained through a pit in the cavity floor towards the end of the
reporting period. Lava fountaining from the N edge of the pit was also
noted. A plume from the vent drifted mainly SW, dropping small amounts
of ash downwind. Measurements on 11 March indicated that the sulfur
dioxide emission rate at the summit remained elevated at 600 tonnes

per day. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless
shield complex flowed SE through the upper portion of a lava tube
system and broke out onto the surface. Thermal anomalies detected by
satellite, and visual observations, revealed active lava flows on the
pali and on the coastal plain.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 5-12 March seismic activity from
Kliuchevskoi was above background levels. Strombolian activity ejected
material 300 m above the crater. Gas-and-steam plumes rose to
altitudes of 5-6.8 km (16,000-22,000 ft) a.s.l. and were occasionally
seen on satellite imagery drifting 80 km E. On 4 March new lava flows
traveled down the S and NE flanks. A satellite image from 9 March
showed that the S-flank lava flow was about 1.3 km long. Phreatic
explosions sometimes occurred from the fronts of the lava flows.
Satellite imagery also revealed a large daily thermal anomaly at the

volcano. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during
10-16 March multiple explosions from Sakura-jima produced plumes that
rose to altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l. and drifted N,
NE, E, and SE. Pilots reported that on 11 and 16 March ash plumes rose
as high as 2.7 km (9,000 ft) a.s.l. and drifted SE and NE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that a thermal anomaly on Sarychev Peak was detected by
satellite on 9 March.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 5-12 March seismic activity from Shiveluch

was above background levels, possibly indicating ash plumes rising to

an altitude of 6.4 km (21,000 ft) a.s.l. Gas-and-steam plumes
sometimes containing ash were seen daily, rising to altitudes of
2.5-3.5 km (8,200-11,500 ft) a.s.l. and drifting 130 km ESE; an ash
plume rose to an altitude of 5.5 km (18,000 ft) a.s.l. on 10 March.

Analyses of satellite imagery revealed a large daily thermal anomaly

from the lava dome. The Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that heavy rains during 5-12 March caused vigorous
steaming from hot deposits emplaced after part of the Soufrière Hills
lava dome collapsed on 11 February. Geysers were visible at Trants
near the old Bramble airport, about 5 km NE, along with ash and steam
ejections. Lahars descended multiple drainages around the volcano.
Cooled lava shed from the dome on 8 and 9 March due to the heavy rains
caused a series of pyroclastic flows to travel W down Gages Valley on
9 March, as far as 2 km. Ashfall from the pyroclastic flows was noted
in NE Montserrat. There was no evidence of fresh lava extrusion. The

Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that rains during 9-11 March caused lahars to descend
drainages on Tungurahua's NW, W, SW, and S flanks. Lahars caused the
road to Baños to close on 10 March and carried blocks up to 50 cm in
diameter on 11 March. Fumarolic activity in the crater was seen during
12-15 March when the weather was clearer.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

leona...@gmail.com

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Mar 17, 2010, 5:57:18 PM3/17/10

to aaron....@mail.mcgill.ca

10 March-16 March 2010

NewActivity/Unrest:

OngoingActivity:

summary ofactivity at volcanoes that meet

NewActivity/Unrest

Map

Source: WashingtonVolcanicAsh Advisory Center (VAAC)

Concepción Information from the Global Volcanism Program

STROMBOLI Aeolian Islands (Italy) 38.789°N, 15.213°E; summit elev.
924
m

INGV-CT reported strong explosions from Stromboli on 10 March mainly
from craters located in the N part of the crater terrace, a flat area
in the upper part of Sciara del Fuoco (a depression cutting the NW
flank of the volcano). After one of the more powerful explosions,
lava
flowed over the NW edge of the crater terrace for tens of meters
before fragmenting and producing small landslides of hot material
that
likely reached the sea.

Geologic Summary. Spectacular incandescent nighttime explosions at
Stromboli volcano have long attracted visitors to the "Lighthouse of
the Mediterranean."Stromboli, the NE-most of the Aeolian Islands, has

lent its name to the frequent mild explosiveactivitythat has

Map

breached to the NE. Mostactivityat Turrialba originated from the

Map

moderate explosiveactivitywith occasional lava effusion. Lahars from

the glacier-covered volcano have damaged towns on its flanks.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN),
Buenos

AiresVolcanicAsh Advisory Center (VAAC)

Villarrica Information from the Global Volcanism Program

YASUR Vanuatu (SW Pacific) 19.53°S, 169.442°E; summit elev. 361 m

On 12 March, Vanuatu Geohazards Observatory reported that thermal
anomalies from Yasur were detected in satellite imagery during 8
December 2009-8 March 2010. They also noted an increase inactivity
since January 2010. Satellite images from 21 January showed
significant sulfur dioxide gas emissions. Bombs were ejected sometime
during the week of 1 March. Observations on 8 March and analyses of

seismic data also indicated increasedactivity, and all three vents

were active. The Vanuatu Volcano Alert Level (VVAL) was raised to 2
(on a scale of 0-4).

Geologic Summary. Yasur, the best-known and most frequently visited
of
the Vanuatu volcanoes, has been in more-or-less continuous
Strombolian

and vulcanianactivitysince Captain Cook observed ash eruptions in
1774. This style ofactivitymay have continued for the past 800

years. Yasur is a mostly unvegetated pyroclastic cone with a nearly
circular, 400-m-wide summit crater. Yasur is largely contained within
the small Yenkahe caldera in SE Tanna Island. It is the youngest of a

group of Holocenevolcaniccenters constructed over the down-dropped

NE flank of the Pleistocene Tukosmeru volcano. Active tectonism along
the Yenkahe horst accompanying eruptions of Yasur has raised Port
Resolution harbor more than 20 m during the past century.

Map

Source: Vanuatu Geohazards Observatory

Yasur Information from the Global Volcanism Program

OngoingActivity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 10-16 March ash plumes from Batu Tara rose to altitudes of
2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted about 20-150 km N, NW,
W, SW, and SSE.

Geologic Summary. The small isolated island of Batu Tara in the
Flores

Sea about 50 km north of Lembata (formerly ...

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Mar 25, 2010, 1:19:26 AM3/25/10

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SI / USGS Weekly VolcanicActivityReport

17 March-23 March 2010

1 new + 11 Ongoing = 12 Actives

Sally Kuhn Sennert - Weekly Report Editor

NewActivity/Unrest:

| Eyjafjöll, Southern Iceland

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)
| Sakura-jima, Kyushu

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Tungurahua, Ecuador

         This page is updated on Wednesdays, please
         see the GVP Home Page for news of the
         latest significant activity.

         The Weekly VolcanicActivityReport is a
         cooperative project between the Smithsonian's
         Global Volcanism Program and the US
         Geological Survey'sVolcanoHazards Program.

        Updated by 2300 UTC every Wednesday,
         notices of volcanicactivityposted on these pages
        are preliminary and subject to change as events
         are studied in more detail.
        This is not a comprehensive list of all of Earth's

volcanoseruptingduring theweek, but rather a

         summary ofactivity at volcanoes that meet
         criteria discussed in detail in the "Criteria and
         Disclaimers" section. Carefully reviewed,
        detailed reports on various volcanoes are
         published monthly in the Bulletin of the Global
         Volcanism Network.

         Note: Many news agencies do not archive the
         articles they post on the Internet, and therefore
         the links to some sources may not be active. To
         obtain information about the cited articles that
         are no longer available on the Internet contact
        the source.

NewActivity/Unrest

EYJAFJOLL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666 m

The Institute of Earth Sciences and the Icelandic Met Office reported
that a fissure eruption from Eyjafjöll (also known as
Eyjafjallajökull) began late at night on 20 March. High rates of
deformation and increased seismic activity were noted during the
previous three weeks; earthquakes were located between 7 and 10 km
below the surface. During 19-20 March earthquakes migrated E and
became more shallow, at 4-7 km depth. At 22:30 on 20 March seismicity
slightly increased and, within the next two hours, reports of a
volcanic eruption were received.

The first reports described incandescence reflected from a cloud above
the eruption area, a 2-km-wide ice-free pass between Eyjafjöll and
Katla volcano (with its overlying Myrdalsjökull ice cap). Lava
fountains, seen from the air on 21 March, were ejected from a 500-m-
long NE-SW trending fissure on the NE flank of Eyjafjöll at an
elevation of about 1,000 m a.s.l. Lava flowed a short distance from
the fissure and a minor plume rose 1 km and drifted W. Tephra fall was
minor or insignificant. According to news articles, flights in and out
of Reykjavík were diverted, delayed, or cancelled. Some local roads
were closed and about 500 people living in nearby areas were
evacuated. A steam explosion on 22 March generated a steam plume that
rose to an altitude of 8 km (26,200 ft) a.s.l. Lava flowed S of the
fissure into a canyon causing steam to rise from where the lava
interacted with snow and ice. The eruption continued during 23-24
March.

Geologic Summary. Eyjafjöll (also known as Eyjafjallajökull) is
located immediately west of Katla volcano. Eyjafjöll consists of an E-
W-trending, elongated ice-covered basaltic-andesite stratovolcano with
a 2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. The sole historical eruption of Eyjafjöll, prior to
an eruption in 2010, produced intermediate-to-silicic tephra from the
central caldera during December 1821 to January 1823.

Map

Sources: Institute of Earth Sciences, Icelandic Met Office, Iceland
Review, Iceland Review, Iceland Review

Eyjafjöll Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 17-18 and 22-23 March ash plumes from Batu Tara rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted about 30-95 km NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores

Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

On 17 March SERNAGEOMIN reported that, during the previous few weeks,
growth of Chaitén's lava-dome complex was concentrated in the W part.
Gas-and-ash plumes, seen through the video camera located on the rim
of the caldera, rose at most 1 km from the central area of the domes.
Seismic activity persisted at a low level. The Alert Level remained at
Red.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 22 March an ash plume from Dukono was
seen on satellite imagery drifting 45 km SE at an altitude of 2.4 km
(8,000 ft) a.s.l.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 17-23 March, HVO reported incandescence from an active lava

surface about 200 m below a vent in the floor of Kilauea's
Halema'uma'u crater. The lava surface circulated and both rose and

drained through a pit in the cavity floor. A plume from the vent
drifted mainly SW, dropping small amounts of ash and spatter downwind.
Measurements on 19 March indicated that the sulfur dioxide emission
rate at the summit remained elevated at 500 tonnes per day. The

2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless
shield complex flowed SE through the upper portion of a lava tube
system and broke out onto the surface. Thermal anomalies detected by

satellite, and visual observations, revealed active lava flows above
the pali. Incandescence was sometimes seen from a vent low on the S

wall of Pu'u 'O'o crater.

Geologic Summary. Kilauea, one of five coalescing volcanoes that

comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 12-19 March seismic activity from

Kliuchevskoi was above background levels. Strombolian activity ejected

material 200 m above the crater and lava continued to flow down the
flanks. Gas-and-steam plumes rose to altitudes of 5 km (16,400 ft)
a.s.l. during 12 and 15-16 March. Satellite imagery revealed a large
daily thermal anomaly at the volcano. Based on information from KVERT,
the Tokyo VAAC reported that on 21 March an ash plume rose to an
altitude of 4.9 km (16,000 ft) a.s.l. and drifted NE. The Aviation

Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

The Tokyo VAAC reported that during 17-23 March plumes from Sakura-

jima identified on satellite imagery, and ash plumes seen by pilots,

rose to altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l. and drifted SE
and E.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 12-19 March seismic activity from Shiveluch

was above background levels, possibly indicating ash plumes rising to

an altitude of 5.5 km (18,000 ft) a.s.l. Hot avalanches were seen at
night. Gas-and-steam plumes sometimes containing ash were seen on 12,
13, 15, and 16 March; plumes seen in satellite imagery on 13 and 16
March drifted 90 km E and SE. Analyses of satellite imagery revealed a
large daily thermal anomaly from the lava dome. Based on information
from KVERT, the Tokyo VAAC reported that on 21 March an ash plume rose
to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted NE. The

Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 12-19 March activity from the Soufrière Hills
lava dome was at a low level. Small incandescent areas on the dome
were visually observed on 14 March. Occasional small pyroclastic flows
and rockfalls occurred from the W and S parts of the dome. The Hazard
Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that although inclement weather often prevented
observations of Tungurahua during 17-23 March, steam-and-gas plumes
were occasionally seen. Explosions were detected by the seismic
network and heard in nearby areas on 19 March; the largest explosion
generated an ash plume that rose to an altitude of 9 km (29,500 ft)
a.s.l. Ashfall was reported in Choglontús, to the SW. On 20 March
small lahars affected the Baños-Penipe highway. On 22 March, ashfall
was again reported in areas to the SW.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

Last Post

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SI / USGS Weekly VolcanicActivityReport

24 March- 30 March 2010

3 new + 10 Ongoing = 13 Actives

Sally Kuhn Sennert - Weekly Report
Editor

NewActivity/Unrest:

| Eyjafjöll, Southern Iceland
| Karymsky, Eastern Kamchatka
| Mauna Loa, Hawaii (USA)

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Llaima, Central Chile

| Sakura-jima, Kyushu
| Santa María, Guatemala

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)

NewActivity/Unrest

According to news articles, the fissure eruption from Eyjafjöll
continued during 24-30 March. On 24 March, steam explosions were seen.
A local scientist described four or five active craters and a 200-
meter-high basalt lava-fall into Hrunagil canyon. Two days later
reports indicated that lava flows had changed course and had entered
the Hvannárgil canyon down a 100-meter-high lava-fall; water levels in
that drainage increased. From a helicopter on 28 March, scientists saw
lava flowing into both canyons and noted fewer jets of lava. The next
evening a swarm of earthquakes in the region measuring M 2-2.5 were
detected. A geophysicist noted that seismicity was gradually
decreasing. The lava covered an area of 1 square kilometer.

Geologic Summary. Eyjafjöll (also known as Eyjafjallajökull) is
located immediately west of Katla volcano. Eyjafjöll consists of an E-
W-trending, elongated ice-covered basaltic-andesite stratovolcano with
a 2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. The sole historical eruption of Eyjafjöll, prior to
an eruption in 2010, produced intermediate-to-silicic tephra from the
central caldera during December 1821 to January 1823.

Map

Sources: Iceland Review, Iceland Review, Iceland Review, Iceland
Review

Eyjafjöll Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity from Karymsky increased on 25
March. Two days later, an intense thermal anomaly over the volcano was
seen in satellite imagery. During 28-29 March ash plumes were seen in
the area of the volcano. The Aviation Color Code level was raised to
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

MAUNA LOA Hawaii (USA) 19.475°N, 155.608°W; summit elev. 4170 m

On 30 March, HVO reported that the Aviation Color Code and the Volcano
Alert Level for Mauna Loa were both lowered to Green and Normal,
respectively. Deformation had not been noted since mid-2009 and
seismicity was at normal levels.

Geologic Summary. Massive Mauna Loa shield volcano rises almost 9 km
above the sea floor to form the world's largest active volcano. Flank
eruptions are predominately from the lengthy NE and SW rift zones, and
the summit is cut by the Mokuaweoweo caldera, which sits within an
older and larger 6 x 8 km caldera. Almost 90% of the volcano's surface
is covered by lavas less than 4,000 years old. During a 750-year
eruptive period beginning about 1,500 years ago, a series of
voluminous overflows from a summit lava lake covered about one fourth
of the volcano's surface. The ensuing 750-year period, from shortly
after the formation of Mokuaweoweo caldera until the present, saw an
additional quarter of the volcano covered with lava flows
predominately from summit and NW rift zone vents.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Mauna Loa Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 24-26 March ash plumes from Batu Tara rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted about 10-120 km W, NW, and NE.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on analyses of satellite imagery, the Buenos Aires VAAC reported
that a plume from Chaitén's lava-dome complex drifted 20 km SW on 29
March.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 24-30 March, HVO reported incandescence from an active lava

surface about 200 m below a vent in the floor of Kilauea's
Halema'uma'u crater. The lava surface circulated and both rose and

drained through a pit in the cavity floor. Plumes from the vent
drifted mainly SW, dropping small amounts of ash, and occasionally
spatter, downwind. Gas measurements on 25 and 26 March indicated that

the sulfur dioxide emission rate at the summit remained elevated at

600 and 800 tonnes per day, respectively. The 2003-2007 average rate

was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless
shield complex flowed SE through the upper portion of a lava tube
system and broke out onto the surface. Thermal anomalies detected by
satellite, and visual observations, revealed active lava flows above
the pali.

Geologic Summary. Kilauea, one of five coalescing volcanoes that

comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 19-29 March seismic activity from

Kliuchevskoi was above background levels. Strombolian activity ejected

material 100-300 m above the crater and lava continued to flow down
the flanks. Satellite imagery revealed a large daily thermal anomaly
from the volcano, and gas-and-steam plumes that drifted over 80 km E
during 18-20 March. Ash plumes seen in satellite imagery drifted about
75 km NE on 21 and 24 March. The Aviation Color Code level remained at
Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

SERNAGEOMIN reported that seismicity from Llaima had generally
decreased during 5-22 March, to levels detected prior to an earthquake
on 27 February. A significant number of earthquakes that indicated
fluid movement in the volcano continued to be registered. Gas-and-
steam plumes rose 100 m from their source. The Alert Level was lowered
to Yellow, (Level 3) on a three-color scale.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent

moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

The Tokyo VAAC reported that during 24-30 March explosions from Sakura-
jima sometimes produced plumes identified on satellite imagery. Those
plumes, along with ash plumes occasionally seen by pilots, rose to
altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted SW, S, SE,
and E.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 29 March, INSIVUMEH reported that explosions from Santa María's
Santiaguito lava dome complex produced ash plumes that rose to
altitudes of 3-3.3 km (10,000-10,800 ft) a.s.l. and drifted W over
inhabited areas. Avalanches from a lava flow descended the SW flank.
The Washington VAAC reported that on 30 March a diffuse ash plume seen
in satellite imagery drifted between the NW and NE.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,

e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 19-29 March seismic activity from Shiveluch

was above background levels, possibly indicating ash plumes rising to

an altitude of 4.2 km (13,800 ft) a.s.l. Hot avalanches from the lava
dome were seen at night. On 22 March, seismic signals detected an
explosion that may have produced an ash plume rising to an altitude of
7 km (23,000 ft) a.s.l. Satellite imagery revealed a large daily
thermal anomaly from the volcano, and ash plumes that drifted over 40
km NE on 21 March. The Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 19-26 March activity from the Soufrière Hills
lava dome was at a low level. Small-to-moderate-sized pyroclastic
flows on the W and S flanks occurred sporadically. The largest
pyroclastic flow traveled 2 km W down Spring Ghaut on 25 March. The

Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion
from Suwanose-jima on 29 March. Details of possible resulting plumes
were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-

jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

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1 March- 6 April 2010

4 new + 8 Ongoing = 12 Actives

Weekly Report Editor Sally Kuhn Sennert -

NewActivity/Unrest:

| Eyjafjöll, Southern Iceland
| Karymsky, Eastern Kamchatka

| Kirishima, Kyushu
| Redoubt, Southwestern Alaska

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Dukono, Halmahera

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Sakura-jima, Kyushu

NewActivity/Unrest

The Icelandic Met Office reported that around 1900 on 31 March a new
fissure at Eyjafjöll opened NE of the first fissure that began
erupting on 20 March. Activity from the second fissure was not
preceded by detectable seismicity. According to a news article, the
fissure was about 300 m long, and about 200 m away from the first
fissure. At the time of reporting by the Icelandic Met Office on 5
April, lava fountains had remained active from both fissures. Lava
mostly accumulated near the new vent but some lava flows had entered
the Hruná and Hvanná gullies. News outlets reported that two people
had died during the journey back from seeing the eruption. The police
estimated that 25,000 people had visited the site since the eruption
began.

Geologic Summary. Eyjafjöll (also known as Eyjafjallajökull) is
located immediately west of Katla volcano. Eyjafjöll consists of an E-
W-trending, elongated ice-covered basaltic-andesite stratovolcano with
a 2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. The sole historical eruption of Eyjafjöll, prior to
an eruption in 2010, produced intermediate-to-silicic tephra from the
central caldera during December 1821 to January 1823.

Map

Sources: Icelandic Met Office, Morgunbladid News, Iceland Review,
Iceland Review

Eyjafjöll Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that during 26 March-2 April seismic activity from
Karymsky was above background levels, possibly indicating ash plumes
rising to an altitude of 4.1 km (13,500 ft) a.s.l. Satellite imagery
revealed an intense daily thermal anomaly from the volcano, and ash
plumes that drifted about 250 km generally E during 28-29 and 31
March. The Aviation Color Code level was raised to Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KIRISHIMA Kyushu 31.931°N, 130.864°E; summit elev. 1700 m

An eruption from Shinmoe-dake (Shinmoe peak), a stratovolcano of the
Kirishima volcano group, on 30 March prompted JMA to raise the Alert
Level from 1 to 2 (on a scale of 1-5). Ash blanketed the ground to the
W of the crater.

Geologic Summary. Kirishima is a large group of more than 20
Quaternary volcanoes located north of Kagoshima Bay. The late-
Pleistocene to Holocene volcano group consists of stratovolcanoes,
pyroclastic cones, maars, and underlying shield volcanoes located over
an area of 20 x 30 km. The larger stratovolcanoes are scattered
throughout the field, with the centrally located, 1,700-m-high
Karakuni-dake being the highest. Onami-ike and Mi-ike, the two largest
maars, are located SW of Karakuni-dake and at its far eastern end,
respectively. Holocene eruptions have been concentrated along an E-W
line of vents from Mi-ike to Ohachi, and at Shinmoe-dake to the NE.
Frequent small-to-moderate explosive eruptions have been recorded
since the 8th century.

Map

Source: Japan Meteorological Agency (JMA)

Kirishima Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

AVO reported that a series of small repetitive earthquakes in the
vicinity of Redoubt's summit were detected on 5 April. The Volcano
Alert Level was raised to Advisory and the Aviation Color Code was
raised to Yellow.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 5 April an ash plume from Batu Tara rose to an altitude of 2.1 km
(7,000 ft) a.s.l. and drifted more than 35 km N.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 2 April an ash plume from Dukono was
seen on satellite imagery drifting 55 km S at an altitude of 2.4 km
(8,000 ft) a.s.l.

Geologic Summary. Reports from this remote volcano in northernmost

Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 31 March-6 April, HVO reported incandescence from a 60-m-wide

active lava surface about 200 m below a vent in the floor of Kilauea's
Halema'uma'u crater. The lava surface circulated and both rose and

drained through a pit in the cavity floor; a few times the level
fluctuated between 235 and 260 m below the surface. Plumes from the
vent drifted mainly SW, dropping small amounts of ash downwind. The
sulfur dioxide emission rate at the summit on 31 March was 1,400
tonnes per day, the highest recorded in 2010. The rate on 1 and 2
April was 1,000 and 650 tonnes per day, respectively.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless
shield complex flowed SE through the upper portion of a lava tube

system and broke out onto the surface. Lava flows advanced E, and then
SE down Pulama pali.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 26 March-2 April seismic activity from
Kliuchevskoi was above background levels, and gas-and-steam plumes
containing small amounts of ash were sometimes seen rising to an
altitude of 5.3 km (17,400 ft) a.s.l. Strombolian activity ejected
material 300 m above the crater and lava continued to flow down the

flanks. Satellite imagery revealed a large daily thermal anomaly from

the volcano, and gas-and-steam plumes that drifted about 70 km E on 30

March. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

The Tokyo VAAC reported that during 31 March-6 April explosions from
Sakura-jima sometimes produced plumes identified on satellite imagery.

Those plumes, along with ash plumes occasionally seen by pilots, rose

to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted SW, SE,
E, and NE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 26 March-2 April seismic activity from

Shiveluch was above background levels, possibly indicating ash plumes

rising to an altitude of 4.7 km (15,400 ft) a.s.l. Hot avalanches from
the lava dome were seen at night. Satellite imagery revealed a large
daily thermal anomaly from the lava dome, and ash plumes that drifted
about 40 km SE on 29 March. Based on information from KVERT, the Tokyo
VAAC reported that on 5 April an ash plume rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted SE. The Aviation Color Code level
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 26 March-2 April activity from the Soufrière
Hills lava dome was at a low level. Rockfalls and pyroclastic flows
occurred sporadically on the W and S flanks. The Hazard Level remained
at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported an explosion

from Suwanose-jima on 2 April. Details of possible resulting plumes
were not reported.

Map

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Apr 14, 2010, 9:14:05 PM4/14/10

to

SI / USGS Weekly VolcanicActivityReport

7 April-13 April 2010

7 new+ 11 Ongoing = 18 Actives

Weekly Report Editor Sally Kuhn Sennert -

http://www.volcano.si.edu/reports/
usgs/

NewActivity/Unrest:

| Egon, Flores Island (Indonesia)
| Etna, Sicily (Italy)
| Eyjafjöll, Southern Iceland

| Gaua, Banks Islands (SW Pacific)

| Miyake-jima, Izu Islands (Japan)
| Redoubt, Southwestern Alaska
| Reventador, Ecuador

Ongoing Activity:

| Arenal, Costa Rica

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera

| Karymsky, Eastern Kamchatka

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Popocatépetl, México
| Rabaul, New Britain

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

New Activity/Unrest

EGON Flores Island (Indonesia) 8.67°S, 122.45°E; summit elev. 1703 m

CVGHM reported that on 7 April the Alert Level for Egon was raised
from 1 to 2 (on a scale of 1-4) due to a marked increase in seismic
activity since 28 March. Small steam plumes normally rose 10 m above
the crater.

Geologic Summary. Gunung Egon volcano sits astride the narrow waist of
eastern Flores Island. The barren, sparsely vegetated summit region
has a 350-m-wide, 200-m-deep crater that sometimes contains a lake.
Other small crater lakes occur on the flanks of the 1,703-m-high
volcano. A lava dome forms the southern 1,671-m-high summit. Reports
of historical eruptive activity are inconclusive. A column of "smoke"
was often observed above the summit during 1888-1891 and in 1892.
Strong "smoke" emission in 1907 reported by Sapper (1917) was
considered by the Catalog of Active Volcanoes of the World (Neumann
van Padang, 1951) to be an historical eruption, but Kemmerling (1929)
noted that this was likely confused with an eruption on the same date
and time from Lewotobi Lakilaki volcano.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Egon Information from the Global Volcanism Program

ETNA Sicily (Italy) 37.734°N, 15.004°E; summit elev. 3330 m

INGV-CT reported that on 8 April a dozen low-frequency events located
near the summit of Etna were detected by the seismic network.
Concurrently, a dark-colored ash plume rose 1 km from a pit crater
located at the E base of the Southeast Crater and drifted NE. Dark
emissions from the central crater were also seen a short time later.
Ashfall was reported from a few local areas. On 9 April intense gas
emissions were noted at the pit crater.

Geologic Summary. Mount Etna, towering above Catania, Sicily's second
largest city, has one of the world's longest documented records of
historical volcanism, dating back to 1500 BC. Historical lava flows
cover much of the surface of this massive basaltic stratovolcano, the
highest and most voluminous in Italy. Two styles of eruptive activity
typically occur at Etna. Persistent explosive eruptions, sometimes
with minor lava emissions, take place from one or more of the three
prominent summit craters, the Central Crater, NE Crater, and SE
Crater. Flank eruptions, typically with higher effusion rates, occur
less frequently and originate from fissures that open progressively
downward from near the summit. A period of more intense intermittent
explosive eruptions from Etna's summit craters began in 1995. The
active volcano is monitored by the Instituto Nazionale di Geofisica e
Volcanologia (INGV) in Catania.

Map

Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di
Catania (INGV-CT)

Etna Information from the Global Volcanism Program

EYJAFJOLL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666 m

The Institute of Earth Sciences reported that on 7 April the eruption
from Eyjafjöll ceased from the original eruption craters and was
limited to the fissure that had opened on 31 March. Lava flows covered
an estimated area of 1.3 square kilometers and were on average 10-20 m
thick. The largest scoria cone was 82 m high. After minor changes in
deformation rates during the eruption, on 9 April deformation returned
to pre-eruption levels. Eruptive activity was observed on 11 April,
but tremor decreased to baseline the next day. Also on 12 April,
according to a new article, the Icelandic Civil Protection Department
decided to lower the preparedness level by one point, from emergency
to danger because of the decreasing activity. Another article stated
that a pilot saw no active lava flows, only steam plumes, during an
overflight on 13 April.

At 2300 on 13 April, a seismic swarm was detected below the central
part of Eyjafjöll, W of the previous eruption fissures. About an hour
later, the onset of seismic tremor heralded an eruption from a new
vent on the S rim of the central caldera, capped by Eyjafjallajökull
glacier. The eruption was visually confirmed early in the morning on
14 April; an eruption plume rose at least 8 km above the glacier.
Meltwater flowed to the N and S. News outlets reported that a circular
ice-free area about 200 m in diameter was seen near the summit.
Scientists conducting an overflight saw a new 2-km-long, N-S-trending
fissure, and ashfall to the E. About 700 people were ordered to
evacuate the area, and certain flights were banned from flying N and E
of the eruption area. Flooding increased throughout the day, causing
road closures and some structural damage.

Geologic Summary. Eyjafjöll (also known as Eyjafjallajökull) is
located immediately west of Katla volcano. Eyjafjöll consists of an E-
W-trending, elongated ice-covered basaltic-andesite stratovolcano with
a 2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. The sole historical eruption of Eyjafjöll, prior to
an eruption in 2010, produced intermediate-to-silicic tephra from the
central caldera during December 1821 to January 1823.

Map

Sources: Institute of Earth Sciences, Icelandic Met Office, Iceland
Review

Eyjafjöll Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

On 7 April, the Vanuatu Geohazards Observatory reported that recent
field observations of Gaua confirmed significant changes in activity.
Gas plumes were detected daily by satellite images. During the end of
March through the beginning of April, ash plumes rose daily to
altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. Explosions were heard
in nearby villages. Starting on 3 April villagers living in the N and
S parts of the island reported ashfall and saw bombs ejected from
Gaua. Based on Vanuatu Geohazards Observatory information, the
Wellington VAAC reported that during 8-12 April ash plumes rose to an
altitude of 3 km (10,000 ft) a.s.l. Ash plumes were seen on satellite
imagery on 11 and 12 April drifting S and SE. The Vanuatu Volcano
Alert Level (VVAL) remained at 2 (on a scale of 0-4).

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Sources: Vanuatu Geohazards Observatory, Wellington Volcanic Ash
Advisory Center (VAAC)

Gaua Information from the Global Volcanism Program

MIYAKE-JIMA Izu Islands (Japan) 34.079°N, 139.529°E; summit elev. 815
m

Based on information from JMA, the Tokyo VAAC reported an eruption
from Miyake-jima on 11 April. Details of possible resulting plumes
were unknown.

Geologic Summary. The circular, 8-km-wide island of Miyake-jima forms
a low-angle stratovolcano that rises about 1100 m from the sea floor
in the northern Izu Islands about 200 km SSW of Tokyo. Parasitic
craters and vents, including maars near the coast and radially
oriented fissure vents, dot the flanks of the volcano. Frequent
historical eruptions have occurred since 1085 AD at vents ranging from
the summit to below sea level, causing much damage on this small
populated island. After a three-century-long hiatus ending in 1469,
activity has been dominated by flank fissure eruptions sometimes
accompanied by minor summit eruptions. A 1.6-km-wide summit caldera
was slowly formed by subsidence during an eruption in 2000; by October
of that year the crater floor had dropped to only 230 m above sea
level.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Miyake-jima Information from the Global Volcanism Program

REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m

AVO reported that the rate of small earthquakes in the vicinity of
Redoubt's summit approached background levels during 7-11 April. Gas
measurements on 8 April were consistent with a passively degassing and
cooling lava dome. The Volcano Alert Level was lowered to Normal and
the Aviation Color Code was lowered to Green on 12 April.

Geologic Summary. Redoubt is a 3108-m-high glacier-covered
stratovolcano with a breached summit crater in Lake Clark National
Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has
been the most active Holocene volcano in the upper Cook Inlet.
Collapse of the summit of Redoubt 10,500-13,000 years ago produced a
major debris avalanche that reached Cook Inlet. Holocene activity has
included the emplacement of a large debris avalanche and clay-rich
lahars that dammed Lake Crescent on the south side and reached Cook
Inlet about 3500 years ago. Eruptions during the past few centuries
have affected only the Drift River drainage on the north. Historical
eruptions have originated from a vent at the north end of the 1.8-km-
wide breached summit crater. The 1989-90 eruption of Redoubt had
severe economic impact on the Cook Inlet region and affected air
traffic far beyond the volcano.

Map

Source: Alaska Volcano Observatory (AVO)

Redoubt Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The IG reported that during 7-13 April observations of Reventador were
not possible because of weather. The Washington VAAC reported that on
8 April an ash plume seen by pilots rose to altitudes of 4.6-6.7 km
(15,000-22,000 ft) a.s.l. and drifted W. Cloud cover prevented
satellite observations of the area. The VAAC also noted that
seismicity was elevated.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),

Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during March activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian

eruptions, and occasional avalanches. A lava flow that began in mid-
January remained active on the S flank. Acid rain and small amounts of
ejected pyroclastic material affected the NE, E, and SE flanks.

Avalanches from the crater and from lava-flow fronts traveled down the
SW, S, and SE flanks, occasionally igniting vegetation. Crater D
produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 6-11 April ash plumes from Batu Tara rose to an altitude of 2.1
km (7,000 ft) a.s.l. and drifted 25-75 km NW, NE, E, and SE.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 9 April an ash plume from Dukono was
seen on satellite imagery drifting over 220 km NE at an altitude of
3.7 km (12,000 ft) a.s.l. During 10-12 April ash plumes rose to
altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted 20-75 km
NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity from Karymsky was above
background on 2 and 3 April and at background levels during 4-9 April.
Satellite imagery revealed a thermal anomaly from the volcano during
3-4 and 6 April. The Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 7-13 April, HVO reported incandescence from a 60-m-wide active
lava surface about 200 m below a 130-m-wide vent in the floor of

Kilauea's Halema'uma'u crater. The lava surface circulated and both
rose and drained through a pit in the cavity floor; a few times the

level fluctuated between 235 and 260 m below the surface. Rocks from
the vent walls fell into the pond, causing spattering. Plumes from the
vent drifted mainly SW, dropping small amounts of ash, and
occasionally Pele's hair and Pele's tears, downwind. Measurements
indicated that the sulfur dioxide emission rate at the summit remained
elevated; 600 and 500 tonnes per day were measured on 8 and 9 April,
respectively.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless
shield complex flowed SE through the upper portion of a lava tube

system and broke out onto the surface. Lava flows moved SE down Pulama
pali.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 2-9 April seismic activity from
Kliuchevskoi was above background levels. Strombolian activity
periodically ejected material 200 m above the crater and lava

continued to flow down the flanks. Satellite imagery revealed a large
daily thermal anomaly from the volcano, and gas-and-steam plumes that

drifted 30-180 km NNE. On 7 April, gas-and-steam plumes containing
small amounts of ash rose to an altitude of 6.3 km (20,700 ft) a.s.l.
The next day, a diffuse ash plume drifted 55-60 km NE. The Aviation

Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that most days during 7-13 April emissions of steam

and gas from Popocatépetl contained minor amounts of ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for

smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported on 9 April that deformation measurements at Rabaul
caldera during the previous 3-4 months showed an inflationary trend
with a total of 4 cm of uplift. During 2-8 April seismicity was low
and variable amounts of white vapor rose from Tavurvur cone.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

The Tokyo VAAC reported that during 7-13 April explosions from Sakura-
jima sometimes produced plumes identified in satellite imagery. Those

plumes, along with ash plumes occasionally seen by pilots, rose to

altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and sometimes drifted
NW, E, and SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 2-9 April seismic activity from Shiveluch
was above background levels. Ash plumes from hot avalanches rose to an
altitude of 6.1 km (20,000 ft) a.s.l. on 5 and 8 April. Satellite

imagery revealed a large daily thermal anomaly from the lava dome, and

ash plumes that drifted about 100 km SE on 5 April. The Tokyo VAAC
reported that on 10 April ash plumes were seen in satellite imagery.

The Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 2-9 April activity from the Soufrière Hills
lava dome was at a low level. Rockfalls occurred sporadically from
several areas of the lava dome. Multiple small areas of incandescence
on the dome were visible several nights during the reporting period.
Heavy rains on 2 April caused lahars in the Farm River and Trants area
(NNE). The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor

Eric Baird

unread,

Apr 20, 2010, 6:48:48 PM4/20/10

to

I notice that the last time Iceland kicked off with a major plume
seems to have been the Laki event in June 1783, which was (no doubt
coincidentally) a couple of months before the big 1783 Mount Asama
eruption in Japan.

=Erk= (Eric Baird)
http://www.scribd.com/doc/30090609/Relativity-in-Curved-Spacetime

Androcles

unread,

Apr 20, 2010, 7:11:35 PM4/20/10

to

"Eric Baird" <-@-.-> wrote in message
news:1g9ss5l7m17vnigac...@4ax.com...

Come off it, Eric, it was 1963.
http://en.wikipedia.org/wiki/Surtsey

leona...@gmail.com

unread,

Apr 28, 2010, 10:47:58 PM4/28/10

to

SI / USGS Weekly Volcanic Activity
Report

21 April-27 April 2010

4 new + 12 Ongoing = 16
Actives

Weekly Report Editor Sally Kuhn Sennert -

NewActivity/Unrest:

| Eyjafjallajökull, Southern Iceland
| Reventador, Ecuador
| Santa María, Guatemala
| Tongkoko, Sulawesi

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera

| Fuego, Guatemala
| Karymsky, Eastern Kamchatka (Russia)

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Llaima, Central Chile
| Pagan, Mariana Islands (Central Pacific)

| Sakura-jima, Kyushu
| Sangay, Ecuador
| Shiveluch, Central Kamchatka (Russia)

This page is updated on Wednesdays, please

NewActivity/Unrest

EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666
m

The Institute of Earth Sciences at the Nordic Volcanological Center
(NVC) reported that the summit eruption from Eyjafjallajökull
continued during 21-27 April. The eruption rate on 21 April was
inferred to have been an order of magnitude smaller than during the
initial 72 hours of the eruption, having declined over the previous
few days. Phreatomagmatic activity with some lava spatter occurred
from the northernmost of two craters in the summit caldera, generating
plumes to an altitude of 3 km (9,800 ft) a.s.l. that drifted S. The
emission of lava flows likely began around 1200 evident by the onset
of semi-continuous meltwater discharge, steaming from the N edge of
the ice cauldron, and changes in tremor amplitude.

Similar activity continued for the next four days, although plumes
sometimes rose to 6 km (19,700 ft) a.s.l. on 22 April. On 23 April
changes in the wind direction pushed the plume NW, causing airports in
SW Iceland to close. The next day, mild explosive activity ejected
spatter 100 m above the crater and shockwaves were detected every few
seconds; an ash plume rose 4 km (13,100 ft) a.s.l. and drifted SW. A
depression in the ice, formed from lava flows that had advanced
400-500 m N of the crater, was 700 m long and steaming, especially at
the edges.

The N crater was active on 25 April. The eruption plume height was
unknown due to meteorological cloud cover at 5.3 km (17,400 ft)
a.s.l.; minor ashfall was noted at two farms 10 km NW of the vents.
Explosions were also heard at locations 10-15 km NW. On 26 April
plumes rose to an average altitude of 4.8 km (15,700 ft) a.s.l. and
drifted E. Radar data showed a tephra crater or cone continuously
building on the N crater. The structure was approximately 150 m high
and 200 m wide. According to news articles, flights from Iceland's
airports resumed.

On 27 April NVC reported that the eruption plume was seen during an
overflight, and rose to altitudes of 3-3.6 km (10,000-11,800 ft)
a.s.l. and drifted WNW. Light ashfall was noted in inhabited areas
between 32 and 45 km W. Scientists also saw that a new crater had
formed in the SW part of the caldera; the rim was about 50 m lower
than the surrounding ice surface. Ash plumes rose from the vent and
spatter was ejected 100-200 m above the vent. The lava flow front had
advanced 1 km N from the vents. Flights from Iceland's airports were
again disrupted.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is
located west of Katla volcano. Eyjafjallajökull consists of an E-W-

trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava

flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last
historical eruption of Eyjafjallajökull prior to an eruption in 2010

produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Sources: Institute of Earth Sciences, Associated Press, Iceland Review

Eyjafjallajökull Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The IG reported that on 20 April scientists conducting an overflight
of Reventador saw steam-and-gas emissions. They also observed an
explosion generate a pyroclastic flow that traveled 200 m down the S
flank. Deposits from previous pyroclastic flows were seen on the same
flank. Explosions generated steam-and-gas plumes with low ash content
during 20-22 April. Weather clouds prevented views of the volcano in
satellite imagery on 23 April, although a pilot reported that an ash
plume rose to an altitude of 4.9 km (16,000 ft) a.s.l. On 26 April a
steam-and-ash plume rose 500 m above the crater.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),
Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 20 April, INSIVUMEH reported that explosions from Santa María's

Santiaguito lava dome complex produced ash plumes that rose to

altitudes of 2.8-3.4 km (9,200-11,200 ft) a.s.l. and drifted S and SE.
On 26 April, ash explosions and pyroclastic flows generated ash plumes
that rose to an altitude of 8.3 km (27,300 ft) a.s.l. and drifted NW
and N. Ashfall was reported in Quetzaltenango (18 km WNW) and other
areas to the W, NW, and N. According to news articles, schools in 10
communities were closed and flights were banned from within a 20-km-
radius of the volcano.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

TONGKOKO Sulawesi 1.52°N, 125.20°E; summit elev. 1149 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 23 April a possible ash plume from Tongkoko rose to an altitude of
10.7 km (35,000 ft) a.s.l.

Geologic Summary. The NE-most volcano on the island of Sulawesi,
Tongkoko (also called Tangkoko) has a summit that is elongated in a NW-
SE direction with a large deep crater that in 1801 contained a cone
surrounded by lake water. The slightly higher Dua Saudara
stratovolcano is located only 3 km to the SW of Tongkoko, and along
with Tongkoko, forms the most prominent features of Gunung Dua Saudara
National Park, a noted wildlife preserve. Eruptions occurred from the
summit crater of Tongkoko in the 17th century and in 1801. The
prominent, flat-topped lava dome Batu Angus originated on the E flank
of Tongkoko in 1801, and, along with an adjacent E-flank vent, has
been the source of all subsequent eruptions.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Tongkoko Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 19-20, 23, 25, and 27 April ash plumes from Bagana rose to
altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted 35-85 km S,
SW, W, and NW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 25-27 April ash plumes from Batu Tara rose to an altitude of
2.1 km (7,000 ft) a.s.l. and drifted 45-85 km W and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 27 April an ash plume from Dukono was
seen on satellite imagery drifting 45 km NW at an altitude of 3 km
(10,000 ft) a.s.l.

Geologic Summary. Reports from this remote volcano in northernmost

Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 26 April, INSIVUMEH reported that explosions from Fuego produced
gray plumes that rose to altitudes of 4.3-4.6 km (14,100-15,100 ft)
a.s.l. and drifted E. A few of the explosions produced avalanches
around the volcano, and rumbling sounds were heard.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that on 16 and 23 April seismic activity from Karymsky
was at background levels. During 17-22 April, seismicity was above
background levels and a thermal anomaly was seen in satellite imagery.
On 17 and 18 April, seismic data suggested that ash plumes rose to an
altitude of 2 km (6,500 ft) a.s.l. Ash plumes were seen in satellite
imagery drifting 40-130 km SE on 17 and 21 April. The Aviation Color

Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 21-27 April HVO reported that activity at Kilauea continued at
the summit and the east rift zone. At the summit, episodic rising and
falling of the lava column continued at the deep pit inset within the
floor of Halema`uma`u crater; glow from the vent was often visible. On
most mornings the plume of gas and ash from the summit vent drifted
SW, depositing small amounts of tephra near the vent. Sulfur dioxide
emission rates measured at the summit during 21-23 April were in the
630-770 tonnes/day range.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 16-23 April seismic activity from
Kliuchevskoi was above background levels. Strombolian activity was
noted and lava continued to flow down the flanks. Gas-and-steam plumes
rose to an altitude of 5.7 km (18,700 ft) a.s.l. Satellite imagery
revealed a large daily thermal anomaly from the volcano, and ash
plumes that drifted about 45 km S on 18 April. Gas-and-steam plumes
drifted 90-100 km E on 20 and 21 April. Based on information from the
Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 27 April an
ash plume rose to an altitude of 7.9 km (26,000 ft) a.s.l. and drifted
W. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

On 26 April, SERNAGEOMIN reported that seismicity from Llaima had
increased on 15 April and that tremor was detected. The Alert Level
was raised to Yellow, (Level 4) on a three-color scale.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

A gas plume from Pagan was seen in satellite imagery on 21 and 22
April (UTC). The Volcano Alert Level and the Aviation Color Code
remained "Unassigned." There are no monitoring instruments on Pagan,
thus the levels "Green" or "Normal" do not apply because background
activity is not defined. Monitoring is done by satellite and ground
observers.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana
Islands, Office of the Governor, United States Geological Survey
Volcano Hazards Program

Pagan Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during
14-26 April explosions from Sakura-jima sometimes produced plumes

identified in satellite imagery. Those plumes, along with ash plumes

occasionally seen by pilots, rose to altitudes of 1.5-3.7 km
(5,000-12,000 ft) a.s.l. and sometimes drifted in multiple directions.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on a pilot observation, the Washington VAAC reported that on 21
April an ash plume from Sangay rose to an altitude of 6.7 km (22,000

ft) a.s.l. Ash was not identified in satellite imagery, although
weather clouds were present in the area.

Geologic Summary. The isolated Sangay volcano, located E of the Andean

crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 16-23 April seismic activity from Shiveluch
was above background levels and ash plumes from hot avalanches rose to
an altitude of 4 km (13,100 ft) a.s.l. Seismic data suggested that ash
plumes rose 4-6.9 km (13,100-22,600 ft) a.s.l. during 15-17 and 20-21
April. An ash explosion on 18 April generated an ash plume that rose
to an altitude of 7 km (23,000 ft) a.s.l. Satellite imagery revealed a

large daily thermal anomaly from the lava dome, and ash plumes that

drifted about 50-220 km SE on 18, 20, and 21 April. The Aviation Color

Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

leona...@gmail.com

unread,

May 13, 2010, 2:01:17 PM5/13/10

to

SI / USGS Weekly Volcanic Activity Report

5 May - 11 May 2010

6 New + 14 Ongoing = 20 active

Weekly Report Editor Sally Kuhn Sennert -

NewActivity/Unrest:

| Eyjafjallajökull, Southern Iceland
| Ketoi, Kuril Islands (Russia)

| Pagan, Mariana Islands (Central Pacific)

| Reventador, Ecuador
| Rinjani, Lombok Island (Indonesia)
| Santa María, Guatemala

Ongoing Activity:

| Aoba, Vanuatu (SW Pacific)
| Bagana, Bougainville
| Dukono, Halmahera

| Gaua, Banks Islands (SW Pacific)

| Karymsky, Eastern Kamchatka (Russia)

| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)
| Popocatépetl, México

| Sakura-jima, Kyushu
| Sangay, Ecuador

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Tungurahua, Ecuador
| Yasur, Vanuatu (SW Pacific)

NewActivity/Unrest

EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666
m

The Institute of Earth Sciences at the Nordic Volcanological Center
(NVC) reported that during 5-11 May the eruption from Eyjafjallajökull
continued to produce ash plumes from the summit vent. Based on
analyses of imagery from weather satellites, scientific overflights,
and pilot reports, ash plumes ranging in color from light gray to
black rose to altitudes of 4-9 km (13,100-29,500 ft) a.s.l. and
drifted ESE, SE, and S. The cinder cone in the summit crater continued
to build and was near the level of the ice on the crater rim on 8 May.

On 5 and 6 May explosive activity increased and effusive activity
decreased, resulting in higher eruption plumes and increased tephra
fallout. The lava flow stopped advancing, and very little steam rose
from the edges of the flow. Ashfall was reported in areas 55-70 km
away during 5-8 May, and was "considerable" on 6 and 7 May. Ash was
reported in a few areas within 12 km E and SSE during 9-10 May.
According to new articles, ash plumes again caused flight disruptions
during 5-11 May in several European countries, including Scotland,
Ireland, Spain, and Portugal.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is

located west of Katla volcano. Eyjafjallajökull consists of an E-W-

trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava

flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last

historical eruption of Eyjafjallajökull prior to an eruption in 2010

produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Sources: Institute of Earth Sciences, Reuters, Agence France-Presse

Eyjafjallajökull Information from the Global Volcanism Program

KETOI Kuril Islands (Russia) 47.35°N, 152.475°E; summit elev. 1172 m

SVERT reported that increased fumarolic activity from Ketoi was noted
in satellite imagery on 4 May.

Geologic Summary. The circular, 10-km-wide Ketoi island, which rises
across the 19-km-wide Diana Strait from Simushir Island, hosts of one
of the most complex volcanic structures of the Kuril Islands. The rim
of a 5-km-wide Pleistocene caldera is exposed only on the NE side. A
younger 1172-m-high stratovolcano forming the NW part of the island is
cut by a horst-and-graben structure containing two solfatara fields. A
1.5-km-wide freshwater lake fills an explosion crater in the center of
the island. Pallas Peak, a large andesitic cone in the NE part of the
caldera, is truncated by a 550-m-wide crater containing a brilliantly
colored turquoise crater lake. Lava flows from Pallas Peak overtop the
caldera rim and descend nearly 5 km to the SE coast. The first
historical eruption of Pallas Peak, during 1843-46, was its largest.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Ketoi Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Steam and gas plumes from Pagan were seen in satellite imagery on 28
April (UTC) and 3 May; no unusual thermal activity was identified. A
visitor to the island saw a minor ash emission on the morning of 3
May. The Aviation Color Code was raised to Yellow and the Volcano
Alert Level was raised to Advisory on 6 May based on the recent
satellite and confirmed minor ashfall on the island.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana
Islands, Office of the Governor, United States Geological Survey
Volcano Hazards Program

Pagan Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The IG reported that during 5-9 May observations of Reventador were

not possible because of weather. The Washington VAAC reported that on

7 May an ash plume seen by a pilot rose to an altitude of 5.2 km
(17,000 ft) a.s.l. Cloud cover prevented satellite observations of the
area. On 8 May the IG noted a small lahar inside the caldera.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),
Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

RINJANI Lombok Island (Indonesia) 8.42°S, 116.47°E; summit elev. 3726
m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 5 May a possible ash plume from Rinjani rose to an altitude of 5.5
km (18,000 ft) a.s.l. and drifted 150 km NW. The plume was not seen in
imagery about six hours later. CVGHM advised the VAAC that
intermittent activity could produce ash plumes to 1.5 km (5,000 ft)
above the caldera.

Geologic Summary. Rinjani volcano on the island of Lombok rises to
3,726 m, second in height among Indonesian volcanoes only to Sumatra's
Kerinci volcano. Rinjani has a steep-sided conical profile when viewed
from the E, but the W side of the compound volcano is truncated by the
6 x 8.5 km, oval-shaped Segara Anak caldera. The western half of the
caldera contains a 230-m-deep lake whose crescentic form results from
growth of the post-caldera cone Barujari at the E end of the caldera.
Historical eruptions at Rinjani dating back to 1847 have been
restricted to Barujari cone and consist of moderate explosive activity
and occasional lava flows that have entered Segara Anak lake.

Map

Source: Darwin Volcanic Ash Advisory Center (VAAC)

Rinjani Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 7 May, INSIVUMEH reported that explosions from Santa María's

Santiaguito lava dome complex produced ash plumes that rose to

altitudes of 2.9-3.4 km (9,500-11,200 ft) a.s.l. and drifted SW.
Seismic stations recorded 17 explosions within 24 hours. On 10 May a
white plume rose 75 m high. No explosions were noted.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

Ongoing Activity

AOBA Vanuatu (SW Pacific) 15.40°S, 167.83°E; summit elev. 1496 m

On 11 May the Vanuatu Geohazards Observatory noted that there had been
recent increases in activity from Aoba, starting with reports that
local villagers saw a plume over the island in December 2009.
Fluctuating gas emissions seen in satellite imagery were also noted at
that time. Satellite imagery on 11 April revealed that sulfur dioxide
emissions increased to a rate of more than 3,000 tons/day. Scientists
flew over Aoba and confirmed increased gas emissions. They also noted
two fumarolic zones in the SE part of Lake Manaro that were surrounded
by discolored water. The Vanuatu Volcano Alert Level (VVAL) remained
at 1 (on a scale of 0-4).

Geologic Summary. Aoba, also known as Ambae, is a massive 2500 cu km
basaltic shield volcano that is the most voluminous volcano of the New
Hebrides archipelago. A pronounced NE-SW-trending rift zone dotted
with scoria cones gives the 16 x 38 km island an elongated form. A
broad pyroclastic cone containing three crater lakes is located at the
summit of the Hawaiian-style shield volcano within the youngest of at
least two nested calderas, the largest of which is 6 km in diameter.
Post-caldera explosive eruptions formed the summit craters of Lake
Voui (also spelled Vui) and Lake Manaro Ngoru about 360 years ago. A
tuff cone was constructed within Lake Voui about 60 years later. The
latest known flank eruption, about 300 years ago, destroyed the
population of the Nduindui area near the western coast.

Map

Source: Vanuatu Geohazards Observatory

Aoba Information from the Global Volcanism Program

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

ash plumes from Bagana rose to altitudes of 2.4-3 km (8,000-10,000 ft)
a.s.l. during 6 and 10-11 May and drifted 65 km W and SW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that during 4 and 8-10 May ash plumes from
Dukono were seen in satellite imagery drifting 25-100 km NW, NE, and
SE at an altitude of 3 km (10,000 ft) a.s.l. On 6 May a pilot reported
that a significant plume rose to an altitude of 4.6 km (15,000 ft)
a.s.l. and drifted NW, but there was no confirmation of the plume in
satellite imagery.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

On 11 May the Vanuatu Geohazards Observatory reported that field
observations of Gaua revealed continued activity during April through
the beginning of May. Significant emissions of gas and ash caused
damage to vegetation around the crater and in areas on the NW, W, and
SW parts of the island, the dominant wind directions. Lahars on the W
part of the island were seen in April. Seismic data revealed that
tremors had become more frequent since the beginning of the year. The

Vanuatu Volcano Alert Level (VVAL) remained at 2 (on a scale of 0-4).

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Vanuatu Geohazards Observatory

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 30 April-7 May seismic activity from
Karymsky was above background levels, suggesting that possible ash
plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Satellite
imagery revealed a thermal anomaly over the volcano during 28 April-2
May. The Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 5-11 May HVO reported that activity at Kilauea continued at the

summit and the east rift zone. At the summit, episodic rising and

falling of the lava-pool surface continued at the deep pit inset

within the floor of Halema'uma'u crater; glow from the vent was

visible. The plume of gas and ash from the summit vent drifted SW and

W, dropping small amounts of ash, and occasionally Pele's hair and

Pele's tears, downwind. The sulfur dioxide emission rate measured at
the summit on 5 May was 880 tonnes/day.

At the east rift zone, lava flows that broke out of the TEB lava-tube
system had advanced down the Pulama pali onto the coastal plain and
headed S into the ocean. Lava also flowed along the highway, after
covering the county viewing area on 5 May. Incandescence was sometimes
seen from a vent low on the S wall of Pu'u 'O'o crater. On 9 May lava
flows near the county viewing area stalled.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 30 April-7 May seismic activity from
Kliuchevskoi was above background levels. Ground observations were
prevented due to meteorological cloud cover. Satellite imagery
revealed a large daily thermal anomaly from the volcano. Ash plumes
drifted 125 km N on 2 May and 70 km W at an altitude of 5.5 km (18,000
ft) a.s.l. on 3 May. Gas-and-steam plumes drifted 55 km W and SW both
days. Based on information from KEMSD, the Tokyo VAAC reported that on
10 May an eruption produced a plume that rose to an altitude of 6.1 km
(20,000 ft) a.s.l. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported emissions of steam and gas from Popocatépetl during
5-11 May. Plumes contained small amounts of ash on 7 May.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 4-6
and 8-9 May explosions from Sakura-jima often produced plumes. Those

plumes, along with ash plumes occasionally seen by pilots, rose to

altitudes of 2.1-3.7 km (7,000-12,000 ft) a.s.l. and sometimes drifted
N, NE, E, and SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 6 May an ash plume from Sangay
was seen by a pilot. Ash was not identified in satellite imagery, but
a diffuse steam-and-gas plume was seen before weather clouds moved
into the area.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 30 April-7 May seismic activity from
Shiveluch was above background levels and suggested that possible ash
plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. Satellite

imagery revealed a large daily thermal anomaly from the lava dome, and

ash plumes that drifted about 18 km W on 3 May. The Aviation Color

Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that activity at Soufrière Hills was low during 30
April-7 May. A pyroclastic flow traveled down the Tar River Valley on
3 May, stopping about 1 km before reaching the sea. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 4-5 and 7-8 May lahars traveled down
Tungurahua's N, W, and SW flanks. No activity from the crater was
noted during 5-11 May, although meteorological cloud cover often
prevented observations.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

YASUR Vanuatu (SW Pacific) 19.53°S, 169.442°E; summit elev. 361 m

On 11 May the Vanuatu Geohazards Observatory reported that, following
an assessment of Yasur during 26-27 April, activity from the volcano
remained high. Strong degassing and ash emissions from all three
active vents were noted. Ash fell on the E and W parts of the island.
New bombs were deposited around the crater rim and in areas near the
vents. Explosions were heard and seen from surrounding villages.
Satellite imagery and seismic data confirmed strong degassing and
explosive activity. The Vanuatu Volcano Alert Level (VVAL) remained at

2 (on a scale of 0-4).

Geologic Summary. Yasur, the best-known and most frequently visited of

the Vanuatu volcanoes, has been in more-or-less continuous Strombolian

and vulcanian activity since Captain Cook observed ash eruptions in
1774. This style of activity may have continued for the past 800

years. Yasur is a mostly unvegetated pyroclastic cone with a nearly
circular, 400-m-wide summit crater. Yasur is largely contained within
the small Yenkahe caldera in SE Tanna Island. It is the youngest of a

group of Holocene volcanic centers constructed over the down-dropped

NE flank of the Pleistocene Tukosmeru volcano. Active tectonism along
the Yenkahe horst accompanying eruptions of Yasur has raised Port
Resolution harbor more than 20 m during the past century.

Map

Source: Vanuatu Geohazards Observatory

Yasur Information from the Global Volcanism Program

leona...@gmail.com

unread,

May 19, 2010, 7:44:57 PM5/19/10

to

SI / USGS Weekly Volcanic Activity
Report

12 May-18 May 2010

4 New+ 14 Ongoing = 18 active

Weekly Report Editor Sally Kuhn Sennert -

www.terradaily.com/reports/Costa_Rica_volcano_erupts_national_park_evacuated_999.html

NewActivity/Unrest:

| Eyjafjallajökull, Southern Iceland
| Kanlaon, Negros I

| Pagan, Mariana Islands (Central Pacific)

| Villarrica, Central Chile

Ongoing Activity:

| Arenal, Costa Rica

| Bagana, Bougainville
| Chaitén, Southern Chile

| Llaima, Central Chile
| Sakura-jima, Kyushu

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)
| Turrialba, Costa Rica

NewActivity/Unrest

(NVC) reported that during 12-18 May the eruption from

Eyjafjallajökull continued to produce ash plumes from the summit vent.
Based on analyses of imagery from weather satellites, scientific

overflights, and pilot reports, gray ash plumes rose to altitudes of
4-9 km (13,100-29,500 ft) a.s.l. and drifted mainly ESE, SE, and S.
Plumes drifted W and SW during 14-15 May, and NE and N on 18 May.
Ashfall was reported in multiple areas, as far away as 40 km SE and
SW, over 50 km SSE, and in Reykjavík 125 km NW. The meltwater
discharge at Gígjökull glacier was low, and deformation measurements
indicated subsidence. According to news reports airports in parts of
multiple European countries including England, Scotland, and Ireland
were closed at times during 16-17 May.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is
located west of Katla volcano. Eyjafjallajökull consists of an E-W-
trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last
historical eruption of Eyjafjallajökull prior to an eruption in 2010
produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Sources: Institute of Earth Sciences, BBC News

Eyjafjallajökull Information from the Global Volcanism Program

KANLAON Negros I 10.412°N, 123.132°E; summit elev. 2435 m

Based on a pilot observation, the Tokyo VAAC reported that on 15 May
an ash plume from Kanlaon rose to an altitude of 2.4 km (8,000 ft)
a.s.l. and drifted W. Ash was not identified in satellite imagery.

Geologic Summary. Kanlaon volcano (also spelled Canlaon), the most
active of the central Philippines, forms the highest point on the
island of Negros, about 500 km ESE of Manila. The massive
stratovolcano is dotted with fissure-controlled pyroclastic cones and
craters, many of which are filled by lakes. The summit of Kanlaon
contains a broad northern crater with a crater lake and a smaller, but
higher, historically active crater to the south. Historical eruptions,
recorded since 1866, have typically consisted of phreatic explosions
of small-to-moderate size that produce minor ashfalls near the
volcano.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Kanlaon Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

During 7-14 May, satellite imagery revealed that a robust steam plume
from Pagan drifted W and a diffuse gas plume drifted farther in the
same direction. Researchers camped on the island reported no unusual
activity. The Aviation Color Code remained at Yellow and the Volcano
Alert Level remained at Advisory.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana
Islands, Office of the Governor, United States Geological Survey
Volcano Hazards Program

Pagan Information from the Global Volcanism Program

VILLARRICA Central Chile 39.42°S, 71.93°W; summit elev. 2847 m

On 12 May, OVDAS-SERNAGEOMIN reported that a slight increase in
activity from Villarrica during April led to a change in the Alert
Level from Green Level 1 to Green Level 2. April's activity was
characterized by increased seismicity, a rise in the lava lake level,
more vigorous fumarolic activity, and more frequent incandescence at
night. According to the Projecto Observación Visual Volcán Villarrica
(POVI), the spattering lava lake was about 100 m below the crater rim
on 10 May.

Geologic Summary. Villarrica, one of Chile's most active volcanoes,
rises above the lake and town of the same name. It is the westernmost
of three large stratovolcanoes that trend perpendicular to the Andean
chain. A 6-km wide caldera formed during the late Pleistocene, more
than 0.9 million years ago. A 2-km-wide postglacial caldera is located
at the base of the presently active, dominantly basaltic-to-andesitic
cone at the NW margin of the Pleistocene caldera. About 25 scoria
cones dot Villarrica's flanks. Plinian eruptions and pyroclastic flows
have been produced during the Holocene from this dominantly basaltic
volcano, but historical eruptions have consisted largely of mild-to-

moderate explosive activity with occasional lava effusion. Lahars from

the glacier-covered volcano have damaged towns on its flanks.

Map

Sources: Observatorio Volcanológico de los Andes del Sur-Servico
Nacional de Geología y Minería (OVDAS-SERNAGEOMIN), Projecto
Observación Visual Volcán Villarrica (POVI)

Villarrica Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during April activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian

eruptions, infrequent ash emissions, and occasional avalanches. A lava
flow that began in mid-January remained active on the S flank. Acid

rain and small amounts of ejected pyroclastic material affected the
NE, E, and SE flanks. Avalanches from the crater and from lava-flow
fronts traveled down the SW, S, and SE flanks, occasionally igniting
vegetation. Crater D produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft)
a.s.l. on 12 May and drifted 55-75 km W and WSW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, the Buenos Aires VAAC reported that an ash
plume from Chaitén's lava-dome complex drifted NE at an altitude of
1.8 km (6,000 ft) a.s.l. on 14 May.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that on 16 and 18 May ash plumes from Dukono
were seen in satellite imagery drifting about 165 km W and NW,
respectively, at an altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

Based on information from the Vanuatu Geohazards Observatory, the
Wellington VAAC reported that on 11 May an ash plume from Gaua rose to

an altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known

as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 7-14 May seismic activity from Karymsky was

above background levels, suggesting that possible ash plumes rose to

altitudes of 2-4.6 km (6,600-15,100 ft) a.s.l. Satellite imagery
revealed a thermal anomaly over the volcano during 8 and 11-13 May.

The Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 12-18 May HVO reported that activity at Kilauea continued from
the summit and the east rift zone. At the summit, occasional rising
and falling of the circulating lava-pool surface continued at the deep

pit inset within the floor of Halema'uma'u crater; glow from the vent

was visible. The plume of gas and ash from the summit vent drifted SW.
On 14 May the sulfur dioxide emission rate measured at the summit
was1,000 tonnes/day. The surface dimensions of the lava pool were an
estimated 60 m by 90 m on 17 and 18 May.

At the east rift zone, lava flows that broke out of the TEB lava-tube
system had advanced down the Pulama pali onto the coastal plain and

headed S into the ocean. Geologists confirmed a collapse of a 17 m by
75 m sliver of Pu'u 'O'o crater's N rim that occurred on 11 May.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 7-14 May seismic activity from Kliuchevskoi
was above background levels and Strombolian activity was seen. Gas-and-
steam plumes containing a small amount of ash were noted during 6 and
8-12 May. Satellite imagery revealed a large daily thermal anomaly
from the volcano, and a gas-and-ash plume that drifted 21 km N on 7
May. Based on information from KVERT, the Tokyo VAAC reported that on
18 May an ash plume rose to an altitude of 5.8 km (19,000 ft) a.s.l.
and drifted NE. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m

SERNAGEOMIN reported that during 1-14 May seismicity from Llaima had
decreased to moderate levels. Small white fumaroles that rose from the
main crater were seen through web cameras. The Alert Level was lowered
to Yellow Level 3 on a three-color scale.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two main historically active craters, one at the
summit and the other to the SE. The massive 3,125-m-high, glacier-
covered stratovolcano has a volume of 400 cu km. A Holocene edifice
built primarily of accumulated lava flows was constructed over an 8-km-
wide caldera that formed about 13,200 years ago, following eruption of
the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the
volcano's flanks. Following the end of an explosive stage about 7,200
years ago, construction of the present edifice began, characterized by
Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent
moderate explosive eruptions with occasional lava flows have been
recorded since the 17th century.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Llaima Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that on 14 May
an explosion from Sakura-jima produced a plume that rose to an

altitude of 2.7 km (9,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,

is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 7-14 May seismic activity from Shiveluch

was above background levels and suggested that possible ash plumes

rose to an altitude of 8.3 km (27,200 ft) a.s.l. on most days. Gas-and-
steam plumes were sometimes seen rising to an altitude of 3.2 km
(10,500 ft) a.s.l. Satellite imagery revealed a large daily thermal
anomaly from the lava dome. The Aviation Color Code level remained at
Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that activity at Soufrière Hills was low during 7-14 May.
A pyroclastic flow traveled as far as 2 km W down Gages Valley on 10
May. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Suwanose-jima during 15-16 May produced plumes that rose to
altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted N and NW.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

OVSICORI-UNA reported that during April a majority of the gases
emitted from Turrialba originated from the vent that opened in
January, producing plumes that rose 2 km. Gas was emitted from other
areas including from fissures SW of the W crater and from multiple
vents and fissures in the main crater. Gas plumes mainly drifted NW,
W, and SW, coincident with areas that had the most vegetation impact
from the plumes.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is

breached to the NE. Most activity at Turrialba originated from the

summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Observatorio Vulcanológico y Sismológico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Turrialba Information from the Global Volcanism Program

leona...@gmail.com

unread,

May 25, 2010, 11:59:49 AM5/25/10

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Costa Rica volcano erupts, national park evacuated

San Jose (AFP) May 24, 2010
Costa Rica's Arenal volcano erupted Monday,
spewing geysers of lava, ash and toxic gases from
its crater and forcing the evacuation of the national
park where it is located, authorities said.

The 1,633-meter-tall (5,450 foot) cone-shaped
mountain in northern Costa Rica shuddered into
activity at midday (1800 GMT), issuing eight
successive rivers of lava that flowed down its steep
slopes, National Volcanology and Seismology
Observatory expert Elicer Duarte told AFP.

He said nobody was at risk from the eruptions but
authorities as a precaution evacuated the Arenal
National Park, 80 kilometers (50 miles) northeast
of San Jose.

The Arenal Volcano is one of Costa Rica's major
tourist attractions and the park has scores of hotels,
restaurants, nightclubs and shopping centers.

No estimates were given of how many people were
inside the park when the eruption began.

Arenal's last major eruption in July 1968 killed 89
people. Smaller eruptions have occurred at least
six times over the past 35 years.

OVSICORI-UNA reported that during April activity originating from
Arenal's Crater C consisted of gas emissions, sporadic Strombolian
eruptions, infrequent ash emissions, and occasional avalanches. A lava
flow that began in mid-January remained active on the S flank. Acid
rain and small amounts of ejected pyroclastic material affected the
NE, E, and SE flanks. Avalanches from the crater and from lava-flow
fronts traveled down the SW, S, and SE flanks, occasionally igniting
vegetation. Crater D produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-
hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow

lava effusion and the occasional emission of pyroclastic ...

Uncle Al

unread,

May 25, 2010, 2:37:21 PM5/25/10

to

"leona...@gmail.com" wrote:
>
> Costa Rica volcano erupts, national park evacuated
>
> www.terradaily.com/reports/Costa_Rica_volcano_erupts_national_park_evacuated_999.html
>
> San Jose (AFP) May 24, 2010
> Costa Rica's Arenal volcano erupted Monday,
> spewing geysers of lava, ash and toxic gases from
> its crater and forcing the evacuation of the national
> park where it is located, authorities said.

[snip]

President Obama immediately declared Puerto Rico to be a disaster zone
and dispatched the US Navy to evacuate all Puerto Ricans from the
Bronx. He later said "I misquoted myself" and declared all Costa
Ricans to be honorary Amercian citizens, then dispatched the US Navy
to evacuate them from Brooklyn.

The White House has declared Project Oil on Troubled Waters a
success! By topping the Gulf of Mexico with a thin hydrocarbon skin,
water evaporation kinetics are deeply impeded and ocean chop is
suppressed. A White House spokesperson said, "the Officially most
devatating Gulf hurricane season in all recorded human history has
been reduced to nothing. $Trillions in damages and million of deaths
have been prevented with one oil well."

The US Department of Energy has been tasked with saving America's
agricultural heartland (Food for Fuel!) from tornadoes, hailstorms,
and lightning fires. Thousands of oil wells are being drilled as you
read this, all leased on political contributors' land.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm

leona...@gmail.com

unread,

May 25, 2010, 3:14:27 PM5/25/10

to

On May 25, 2:37 pm, Uncle Al <Uncle...@hate.spam.net> wrote:

> "leonard7...@gmail.com" wrote:
>
> > Costa Rica volcano erupts, national park evacuated
>

> >www.terradaily.com/reports/Costa_Rica_volcano_erupts_national_park_ev...

>
> > San Jose (AFP) May 24, 2010
> > Costa Rica's Arenal volcano erupted Monday,
> > spewing geysers of lava, ash and toxic gases from
> > its crater and forcing the evacuation of the national
> > park where it is located, authorities said.
>
> [snip]

Ø The idiot fascist jackass Al always posts off topic spam
and thinks he is funny
4Q Al.

—— ——
There are three types of people that you
can_not_talk_into_behaving_well. The
stupid, the religious fanatic, and the evil.

1- The stupid aren't smart enough to follow the
logic of what you say. You have to tell them
what is right in very simple terms. If they do
not agree, you will never be able to change
their mind.

2- The religious fanatic: If what you say goes
against their religious belief, they will cling to
that belief even if it means their death.

3- There is no way to reform evil- not in a
million years. There is no way to convince

the anthropogenic_global_warming_alarmists,

the terrorists, serial killers, paedophiles, and

predators to change their evil ways, They
knew what they were doing was wrong, but
knowledge didn't stop them. It only made
them more careful in how they went about
performing their evil deeds.

leona...@gmail.com

unread,

May 26, 2010, 7:32:11 PM5/26/10

to

SI / USGS Weekly Volcanic Activity Report

19 May-25 May 2010

4 New+ 14 Ongoing = 18 active

Weekly Report Editor Sally Kuhn Sennert -

NewActivity/Unrest:

| Arenal, Costa Rica
| Cleveland, Chuginadak Island
| Eyjafjallajökull, Southern Iceland

| Pagan, Mariana Islands (Central Pacific)

| Rinjani, Lombok Island (Indonesia)

Ongoing Activity:
| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)

| Fuego, Guatemala

| Gaua, Banks Islands (SW Pacific)
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Pacaya, Guatemala

| Sakura-jima, Kyushu
| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Ulawun, New Britain

NewActivity/Unrest

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

According to news articles, an eruption from Arenal on 24 May produced
gas and ash emissions as well as multiple lava flows, prompting the
evacuation of Arenal National Park.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Agence France-Presse

Arenal Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

On 25 May, AVO raised the Volcano Alert Level for Cleveland to
Advisory and the Aviation Color Code to Yellow because thermal
anomalies from the crater were seen in satellite imagery during the
previous few days.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666
m

The Nordic Volcanological Center (NVC) at the Institute of Earth
Sciences reported that during 19-24 May overall activity from
Eyjafjallajökull declined, and deformation measurements indicated
subsidence. During 19-20 May gray ash plumes rose to altitudes of 5-6
km (16,400-19,700 ft) a.s.l. and drifted NW, N, and NE. Ashfall was
reported in areas to the S, NW, and N. On 19 May heavy rainfall
combined with ashfall to cause a mudslide in a local river. During
21-22 May light gray plumes with small amounts of ash rose to
altitudes of 3-4 km (9,800-13,100 ft) a.s.l. No ashfall was reported.
Some explosions occurred in the summit crater those days, but no lava
flows. Seismicity continued to decrease and approached pre-eruption
levels. White steam plumes rose from the crater during 23-25 May,
though a small ash explosion was seen by scientists visiting the
crater on 25 May.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is
located west of Katla volcano. Eyjafjallajökull consists of an E-W-
trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last
historical eruption of Eyjafjallajökull prior to an eruption in 2010
produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Source: Institute of Earth Sciences

Eyjafjallajökull Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Satellite imagery revealed steam plumes from Pagan during 14-21 May.
On 21 May researchers camping on the island reported that a trace
amount of ash was deposited on their tents from activity through the
night. The Aviation Color Code remained at Yellow and the Volcano

Alert Level remained at Advisory.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana
Islands, Office of the Governor, United States Geological Survey
Volcano Hazards Program

Pagan Information from the Global Volcanism Program

RINJANI Lombok Island (Indonesia) 8.42°S, 116.47°E; summit elev. 3726
m

According to news articles, three eruptions from Rinjani during 22-23
May were accompanied by tremors. Ash and incandescent material was
ejected as high as 2 km. Ash plumes drifted 12 km and caused ashfall
in multiple areas. Lava flowed into the caldera lake and caused the
lake water temperature to rise from 21 to 35 degrees Celsius.

Geologic Summary. Rinjani volcano on the island of Lombok rises to
3,726 m, second in height among Indonesian volcanoes only to Sumatra's
Kerinci volcano. Rinjani has a steep-sided conical profile when viewed
from the E, but the W side of the compound volcano is truncated by the
6 x 8.5 km, oval-shaped Segara Anak caldera. The western half of the
caldera contains a 230-m-deep lake whose crescentic form results from
growth of the post-caldera cone Barujari at the E end of the caldera.
Historical eruptions at Rinjani dating back to 1847 have been
restricted to Barujari cone and consist of moderate explosive activity
and occasional lava flows that have entered Segara Anak lake.

Map

Source: RTT News

Rinjani Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

an ash plume from Bagana rose to an altitude of 3 km (10,000 ft)
a.s.l. on 25 May and drifted 55-160 km NW and W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 20 May an ash plume from Batu Tara rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 65 km W.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 20 May, INSIVUMEH reported that explosions from Fuego produced ash
plumes that rose to altitudes of 4.4-4.8 km (14,400-15,700 ft) a.s.l.
and drifted SW. Incandescent material was ejected to heights of 100 m
and avalanches descended the S and W flanks.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

Based on information from the Vanuatu Geohazards Observatory and
analyses of satellite imagery, the Wellington VAAC reported that
during 18-19 and 21-22 May ash plumes from Gaua rose to an altitude of
3 km (10,000 ft) a.s.l. and occasionally drifted W.

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 14-21 May seismic activity from Karymsky

was above background levels, suggesting that possible ash plumes rose

to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery revealed
a thermal anomaly over the volcano during 13-17 and 19-20 May, and an
ash plume that drifted 18 km NE on 17 May. Based on information from
the Yelizovo Airport (UHPP) and KVERT, the Tokyo VAAC reported that on
22 and 25 May ash plumes rose to an altitude of 4.3 km (14,000 ft)
a.s.l. and drifted SW and W. The Aviation Color Code level remained at
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 19-25 May HVO reported that activity at Kilauea continued from

the summit and the east rift zone. At the summit, occasional rising

and falling of the circulating, crusting, and bubbling lava-pool

surface continued at the deep pit inset within the floor of
Halema'uma'u crater; glow from the vent was visible. The plume of gas

from the summit vent drifted SW. Sulfur dioxide emission rates
measured at the summit during 19-21 and 24 May were in the 800-1,200
tonnes/day range.

At the east rift zone, lava flows that broke out of the TEB lava-tube
system had advanced down the Pulama pali onto the coastal plain and

headed S, entering the ocean at Ki. Other lava flows were active on
the flow field. A small lava flow issued from a vent on Pu'u 'O'o's S
crater wall on 21 May.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 14-21 May seismic activity from

Kliuchevskoi was above background levels and Strombolian activity was

seen. Gas-and-steam plumes containing a small amount of ash were noted
during 13-18 May. Satellite imagery revealed a large daily thermal
anomaly from the volcano, and ash plumes that drifted 20-145 km E on
most days. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 20 May, INSIVUMEH reported that small explosions and incandescence
from Pacaya's MacKenney cone were accompanied by white and blue
plumes. Multiple lava flows traveled as far as 1.6 km down the SW
flank.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that on 21 May

an explosion from Sakura-jima produced a plume that rose to an

altitude higher than 2.1 km (7,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

During 19-20 May, INSIVUMEH reported that hot lahars traveled down
Santa María's Nima I, Nima II, and San Isidro rivers. The lahar in the
San Isidro channel was 30 m wide and 1.5-2 m deep, emitted a sulfur
odor, and carried blocks up to 2 m in diameter. Explosions from the
Santiaguito lava dome complex produced ash plumes that rose to an
altitude of 2.9-3.4 km (9,500-11,200 ft) a.s.l. and drifted SW. The
next day, an explosion produced a plume that rose to an altitude of
3.3 km (10,800 ft) a.s.l. and drifted E and a pyroclastic flow that
traveled SW. On 21 May another lahar descended the Nima II River.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 14-21 May seismic activity from Shiveluch
was above background levels, suggesting that possible ash plumes rose
to an altitude of 5.1 km (16,700 ft) a.s.l. Satellite imagery revealed
a large daily thermal anomaly from the lava dome. An ash plume drifted
about 40 km SE on 15 May and gas-and-steam plumes drifted the same
distance NE on 18 May. Based on information from KVERT, the Tokyo VAAC
reported that on 24 May an ash plume rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted NE. Ash was not identified on satellite
imagery. The Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that during 1-20 May Ulawun emitted variable amounts of
white vapor. Based on analyses of satellite imagery, the Darwin VAAC
reported that during 22-25 May ash plumes drifted 35-130 km at an

altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun

stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Last Post

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Jun 9, 2010, 11:06:43 PM6/9/10

to aaron....@mail.mcgill.ca

SI / USGS Weekly Volcanic Activity Report

19 May-25 May 2010

7 New+ 10 Ongoing = 17 active

Weekly Report Editor Sally Kuhn Sennert -

New Activity/Unrest:

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera
| Eyjafjallajökull, Southern Iceland

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Popocatépetl, México

summary of activity at volcanoes that meet

    criteria discussed in detail in the "Criteria and
    Disclaimers" section. Carefully reviewed,
    detailed reports on various volcanoes are
    published monthly in the Bulletin of the Global
    Volcanism Network.

    Note: Many news agencies do not archive the
    articles they post on the Internet, and therefore
    the links to some sources may not be active. To
   obtain information about the cited articles that
    are no longer available on the Internet contact
    the source.

New Activity/Unrest

BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit
elev. 2882 m

KVERT reported that after an explosive eruption from Bezymianny on 1
June two bright thermal anomalies on the flanks were seen in satellite
imagery during 1-2 June, possibly from pyroclastic flow deposits. On 4
June KVERT noted that strong gas-and-steam emissions continued to rise
from the lava dome. The Aviation Color Code level was lowered to
Yellow.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny

volcano had been considered extinct. Three periods of intensified
activity have occurred during the past 3,000 years. The latest period,
which was preceded by a 1,000-year quiescence, began with the dramatic
1955-56 eruption. That eruption, similar to the 1980 event at Mount
St. Helens, produced a large horseshoe-shaped crater that was formed
by collapse of the summit and an associated lateral blast. Subsequent
episodic but ongoing lava-dome growth, accompanied by intermittent
explosive activity and pyroclastic flows, has largely filled the 1956
crater.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bezymianny Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

AVO reported that a weak thermal anomaly from Cleveland was detected
in satellite imagery on 2 June. Cloud cover mostly prevented
observations during 3-8 June. The Volcano Alert Level remained at
Advisory and the Aviation Color Code remained at Yellow.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that on 3 June Strombolian activity from Pacaya
ejected material 200 m into the air. During 5-6 June no explosions or
ash emissions were noted, and seismic energy remained stable. Bluish-
white plumes rose 700 m and drifted W. On 7 June an explosion ejected
ash 100 m above the crater resulting in an ash plume that drifted 2 km
NW. Blue-and-white plumes continued to rise from MacKenney cone.
Multiple lava flows remained active and had traveled as far as 3.5 km
by 6 June.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

TAAL Luzon 14.002°N, 120.993°E; summit elev. 311 m

On 8 June, PHIVOLCS raised the Alert Level for Taal to 2 (scale is
0-5, 0 referring to No Alert status) due to changes in several
monitored parameters, starting in late April. Since 26 April the
number of earthquakes per day continued to increase, as well as the
magnitude. Low-frequency volcanic earthquakes were detected on 2 June,
and during the previous day high-frequency earthquakes were noted. In
addition to increased seismicity, the temperature of the Main Crater
Lake increased from 32 degrees Celsius on 11 May to 34 degrees Celsius
on 24 May. Steaming from the N and NE sides of Main Crater
occasionally intensified. Deformation data had shown slight inflation
since 2004; measurements taken at the SE side of Taal on 7 June showed
further inflation by 3 mm.

Geologic Summary. Taal volcano is one of the most active volcanoes in
the Philippines and has produced some of its most powerful historical
eruptions. In contrast to Mayon volcano, Taal is not topographically
prominent, but its prehistorical eruptions have greatly changed the
topography of SW Luzon. The 15 x 20 km Taal caldera is largely filled
by Lake Taal, whose 267 sq km surface lies 700 m below the S caldera
rim and only 3 m above sea level. The maximum depth of the lake is 160
m, and several eruptive centers lie submerged beneath the lake. The 5-
km-wide Volcano Island in north-central Lake Taal is the location of
all historical eruptions. The island is a complex volcano composed of
coalescing small stratovolcanoes, tuff rings, and scoria cones that
has grown about 25% in area during historical time. Powerful
pyroclastic flows and surges from historical eruptions of Taal have
caused many fatalities.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Taal Information from the Global Volcanism Program

TIATIA Kunashir Island 44.351°N, 146.256°E; summit elev. 1819 m

SVERT reported that a thermal anomaly from Tiatia was detected by
satellite on 31 May. Tiatia does not have a seismic network; satellite
image observations are the primary tool for monitoring many of the
Kurile Islands volcanoes.

Geologic Summary. Tiatia volcano, one of the most impressive of the
Kuril Islands, consists of a beautifully symmetrical cone that rises
above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide
caldera. The 1819-m-high Tiatia (also known as Chacha-dake) occupies
the NE tip of Kunashir Island and morphologically resembles Mount
Vesuvius. The pristine-looking conical central cone, mostly formed by
basaltic to basaltic-andesite strombolian eruptions, rises 400 m above
the floor of the caldera and contains a 400 x 250 m wide crater with
two explosion vents separated by a linear septum. Fresh lava flows
cover much of the SW caldera floor and have overflowed the rim,
extending to the foot of the older somma, which formed during the late
Pleistocene or early Holocene. A lava flow from a flank cone on the
northern caldera rim reached the Sea of Okhotsk. A major explosive
eruption in 1973 was the first since Tiatia's initial historical
eruption in 1812.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Tiatia Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Although storm clouds often prevented observations of Tungurahua's
summit area during 1-8 June, steam-and-ash plumes generated by
explosions were sometimes seen and rose to altitudes of 6-8 km
(19,700-26,200 ft) a.s.l. Larger explosions occasionally produced ash
plumes that rose as high as an altitude of 9 km (29,500 ft) a.s.l.
Daily reports of ashfall came from multiple areas within about 8 km
NW, W, and SW. Explosions ejected blocks (that were occasionally
incandescent) almost daily as high as 1 km above the crater rim. The
blocks that fell outside of the crater descended the flanks a maximum
distance of 2 km. Noises resembling "cannon shots" associated with
explosions were often followed by vibrating windows and doors in local
areas; on 6 June large windows vibrated at Tungurahua Observatory
(OVT) in Guadalupe, 11 km N.

On 2 June a pyroclastic flow traveled 1.5 km down the NW flank. During
5-7 June ashfall was noted in areas farther away, including at OVT and
Cevallos, 23 km NW. Explosions on 7 and 8 June generated ash plumes
that rose to altitudes of 9-10 km (29,500-32,800 ft) a.s.l. and
drifted W. On 7 June another small pyroclastic flow traveled 1.5 km
down the NW flank.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that during 2-7 June occasional low roaring or rumbling
noises from Ulawun were heard daily in areas on the ESE, SE, and S
flanks. During 2-5 June white vapor plumes rose 800-900 m high. Very
fine ash particles fell in Ulamona about 10 km NW on 3 June and some
gray emissions rose from the volcano on 5 June. Emissions during 6-9
June were white and light gray, and continued to rise no higher than
900 m. Fluctuating incandescence from the crater was seen at night
from the S side of the volcano. Ashfall was again reported in Ulamona
on 8 June.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 2-7 June ash plumes from Batu Tara rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 20-65 km W, NW, and N.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 2 June an ash plume from Dukono rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 110 km NW. On 7 June a diffuse ash plume
was seen drifting 110 km W at an altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666
m

The Nordic Volcanological Center (NVC) at the Institute of Earth

Sciences reported that on 2 June a white steam cloud from
Eyjafjallajökull's summit caldera rose to an altitude of 2.5 km (8,200
ft) a.s.l. On 3 June, scientists visited the summit and noted that the
main crater remained active, though it was less active than during the
previous visit on 27 May; steam rose 200-400 m above the crater rim.
The next day cloud cover prevented observations. During 3-4 June
remobilized ash drifted over a wide area of S and SW Iceland.

Scientists noted increased tremor on 4 June and a black plume that
rose to an altitude of 4.5 km (14,800 ft) a.s.l. Considerable rumbling
noises were reported from an area 10 km S. Tremor levels fluctuated
during the next three days. Plumes that rose from the summit caldera
were mostly white with occasional dark areas at the base following
explosive activity. Plumes drifted SW during 4-5 June and S during 6-7
June at altitudes of 3-6 km (9,800-19,700 ft) a.s.l. A new crater was
seen in the W part of the caldera at the site of the new explosive
activity.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is
located west of Katla volcano. Eyjafjallajökull consists of an E-W-
trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last
historical eruption of Eyjafjallajökull prior to an eruption in 2010
produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Sources: Institute of Earth Sciences, Iceland Review

Eyjafjallajökull Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 28 May-4 June seismic activity from

Karymsky was above background levels, suggesting that possible ash

plumes rose to an altitude of 4 km (13,100 ft) a.s.l. Satellite
imagery revealed a daily thermal anomaly over the volcano and ash
plumes that drifted 30 km S on 1 June. The Aviation Color Code level
remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 2-8 June HVO reported that activity at Kilauea continued from
the summit and the east rift zone. At the summit, the level of the
circulating, crusting, and bubbling lava-pool surface remained mostly
stable in the deep pit inset within the floor of Halema'uma'u crater;
glow from the vent was visible. A plume from the vent drifted SW,
dropping small amounts of ash and spatter downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube

system at 580 m elevation built up rootless shields. Minor surface
lava flows from the shields were active on the pali and the coastal
plain. Lava stopped flowing into the ocean at the Ki entry sometime
during 2-3 June. The Pu'u 'O'o' web camera recorded a growing and
circulating lava pond on the crater floor that on 5 June was an
estimated 300 x 125 m in dimension. A small spattering cone was seen
on the floor to the N of the pond.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 28 May-4 June seismic activity from

Kliuchevskoi was above background levels and Strombolian activity was

seen. Gas-and-steam plumes occasionally containing a small amount of
ash were also noted. Satellite imagery revealed a large daily thermal
anomaly from the volcano, and ash plumes that drifted 40 km NW on 28
and 31 May. On 1 June an ash plume rose to an altitude of 7.3 km
(24,000 ft) a.s.l. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 2-3 and 7-8 June steam-and-gas emissions
from Popocatépetl occasionally contained small amounts of ash. The
seismic network detected a few periods of harmonic tremor. Steam-and-
gas emissions continued during 4-7 June. On 8 June a moderate
explosion generated an ash plume that rose to an altitude of 8.4 km
(27,600 ft) a.s.l.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA and pilot observations, the Tokyo VAAC
reported that on 3 June an eruption from Sakura-jima produced a plume
that rose to altitudes of 2.1-3.4 km (7,000-11,000 ft) a.s.l. and
drifted W.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,

is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 4 June, INSIVUMEH reported that a 12-m-wide lahar descended Santa
María's Nima I river, carrying blocks up to 60 cm in diameter.
Tropical storm Agatha had brought abundant rain to the area.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 28 May-4 June seismic activity from

Shiveluch was above background levels, suggesting that possible ash

plumes rose to an altitude of 6.1 km (20,000 ft) a.s.l. Strong
fumarolic activity was also noted and, at night, hot avalanches were
seen. Ash plumes observed throughout the reporting period rose to an
altitude of 4.5 km (14,800 ft) a.s.l. Satellite imagery showed a large
daily thermal anomaly. Gas-and-steam plumes seen in imagery drifted 30
km W on 29 May, and an ash cloud 20 by 6 km in dimension was detected
about 15 km N on 31 May. The Aviation Color Code level remained at
Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

leona...@gmail.com

unread,

Jun 16, 2010, 9:34:16 PM6/16/10

to

SI / USGS Weekly Volcanic Activity Report

9 June-15 June 2010

9 New+ 13 Ongoing = 22 active

Weekly Report Editor Sally Kuhn Sennert -

New Activity/Unrest:

| Bezymianny, Central Kamchatka (Russia)
| Cleveland, Chuginadak Island

| Melimoyu, Southern Chile
| Pacaya, Guatemala
| San Cristóbal, Nicaragua
| Sarigan, Mariana Islands (Central Pacific)

| Tiatia, Kunashir Island
| Tungurahua, Ecuador
| Ulawun, New Britain

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)

| Dukono, Halmahera
| Eyjafjallajökull, Southern Iceland

| Popocatépetl, México

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

New Activity/Unrest

KVERT reported that although clouds prevented views of Bezymianny
during 4-11 June, thermal anomalies were seen in satellite imagery
during 4-5 and 8 June. The Aviation Color Code level remained at
Yellow.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny
volcano had been considered extinct. Three periods of intensified
activity have occurred during the past 3,000 years. The latest period,
which was preceded by a 1,000-year quiescence, began with the dramatic
1955-56 eruption. That eruption, similar to the 1980 event at Mount
St. Helens, produced a large horseshoe-shaped crater that was formed
by collapse of the summit and an associated lateral blast. Subsequent
episodic but ongoing lava-dome growth, accompanied by intermittent
explosive activity and pyroclastic flows, has largely filled the 1956
crater.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bezymianny Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

AVO reported that on 11 June the Volcano Alert Level and the Aviation
Color Code for Cleveland was lowered to Unassigned; no activity or
unrest was detected during 4-11 June.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

MELIMOYU Southern Chile 44.08°S, 72.88°W; summit elev. 2400 m

ODVAS-SERNAGEOMIN reported on 8 June that the Alert Level for Melimoyu
was raised to Green Level 2 due to increased seismicity during May,
specifically starting with nine long-period earthquakes on 27 May. The
next day six long-period earthquakes preceded two separate seismic
swarms. The first swarm was located 2-12 km beneath the summit.
Earthquakes in the second swarm were located 7-14 km S of the summit
at depths no greater than 15 km. All earthquakes were M 2.5 or less.

Geologic Summary. Melimoyu is a stratovolcano with an 8-km-wide,
largely buried caldera located about 40 km NW of the town of
Puyuhuapi. The ice-filled caldera is drained by a glacier through a
notch in the NE caldera rim. The basaltic-andesite volcano is
elongated 10 km in an E-W direction and has several cinder cones. A 1-
km-wide crater is located at the summit of the volcano. Two late-
Holocene tephra layers have been documented from Melimoyu.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Melimoyu Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that during 9-10 June Pacaya's MacKenney cone
emitted white-and-blue fumarolic plumes that rose 300 m high, and
generated sounds audible up to 5 km away that resembled airplane
engines. Occasional ash plumes drifted 2 km NW. Lava flows continued
to be active on the SE flank and moved at a speed of about 1 m per
hour. Explosions continued from a lateral crater.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

SAN CRISTOBAL Nicaragua 12.702°N, 87.004°W; summit elev. 1745 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 9 June a well-defined ash plume from San Cristóbal drifted
about 115 km WNW.

Geologic Summary. The San Cristóbal volcanic complex, consisting of
five principal volcanic edifices, forms the NW end of the Marrabios
Range. The symmetrical 1,745-m-high youngest cone, San Cristóbal
itself (also known as El Viejo), is Nicaragua's highest volcano and is
capped by a 500 x 600 m wide crater. El Chonco, with several flank
lava domes, is located 4 km to the west of San Cristóbal; it and the
eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of
Pleistocene age. Volcán Casita contains an elongated summit crater and
lies immediately E of San Cristóbal; Casita was the site of a
catastrophic landslide and lahar in 1998. The Plio-Pleistocene La
Pelona caldera is located at the eastern end of the San Cristóbal
complex. Historical eruptions from San Cristóbal, consisting of small-
to-moderate explosive activity, have been reported since the 16th
century. Some other 16th-century eruptions attributed to Casita
volcano are uncertain and may pertain to other Marrabios Range
volcanoes.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

San Cristóbal Information from the Global Volcanism Program

SARIGAN Mariana Islands (Central Pacific) 16.708°N, 145.78°E; summit
elev. 538 m

On 10 June the Volcano Alert Level and the Aviation Color Code for
Sarigan was lowered to Unassigned because no further volcanic activity
was noted since the submarine eruption from a vent S of the island on
29 May.

Geologic Summary. Sarigan volcano forms a 3-km-long, roughly
triangular island. A low truncated cone with a 750-m-wide summit
crater contains a small ash cone. The youngest eruptions produced two
lava domes from vents above and near the S crater rim. Lava flows from
each dome reached the coast and extended out to sea, forming irregular
shorelines. The northern flow overtopped the crater rim on the N and
NW sides. The sparse vegetation on the flows indicates they are of
Holocene age.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana

Islands and the US Geological Survey Hawaiian Volcano Observatory

Sarigan Information from the Global Volcanism Program

TIATIA Kunashir Island 44.351°N, 146.256°E; summit elev. 1819 m

SVERT reported that a thermal anomaly from Tiatia was detected by

satellite on 10 June. Tiatia does not have a seismic network;

satellite image observations are the primary tool for monitoring many
of the Kurile Islands volcanoes.

Geologic Summary. Tiatia volcano, one of the most impressive of the
Kuril Islands, consists of a beautifully symmetrical cone that rises
above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide
caldera. The 1819-m-high Tiatia (also known as Chacha-dake) occupies
the NE tip of Kunashir Island and morphologically resembles Mount
Vesuvius. The pristine-looking conical central cone, mostly formed by
basaltic to basaltic-andesite strombolian eruptions, rises 400 m above
the floor of the caldera and contains a 400 x 250 m wide crater with
two explosion vents separated by a linear septum. Fresh lava flows
cover much of the SW caldera floor and have overflowed the rim,
extending to the foot of the older somma, which formed during the late
Pleistocene or early Holocene. A lava flow from a flank cone on the
northern caldera rim reached the Sea of Okhotsk. A major explosive
eruption in 1973 was the first since Tiatia's initial historical
eruption in 1812.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Tiatia Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Although storm clouds occasionally prevented observations of
Tungurahua's summit area during 9-12 June, steam-and-ash plumes were
seen and rose to altitudes of 5.5-8 km (18,000-29,500 ft) a.s.l. Daily

reports of ashfall came from multiple areas within about 8 km NW, W,

and SW, but ash was noted as far away as 22 km NW and 25 km W on 9
June. Blocks, including some that were incandescent, occasionally
ejected by explosions rolled at most 1 km down the flanks. Explosions
caused noises resembling "cannon shots" and vibrating windows almost
daily. During 13-14 June steam plumes from the crater and the NW flank
rose 500-1,000 m above the crater and drifted W. An explosion on 15
June generated an ash plume that rose to an altitude of 7 km (23,000

ft) a.s.l. and drifted W.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more

than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that during 9-16 June white and gray plumes from Ulawun
rose 800-900 m high. Fine ashfall was reported almost daily and
affected the NW, W, and SW flanks. During 9-12 June occasional
rumbling noises were reported. Fluctuating incandescence from the
crater was seen at night on 9 and 10 June from observers in areas to
the SW and for a brief period of time on 13 June from areas N.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

ash plumes from Bagana rose to an altitude of 3 km (10,000 ft) a.s.l.
during 13-14 June and drifted 75-205 km SW and W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 9 and 11-15 June ash plumes from Batu Tara rose to an altitude
of 2.4 km (8,000 ft) a.s.l. and drifted 35-65 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

The Darwin VAAC reported that during 9-10 June an ash plume from
Dukono was seen in satellite imagery drifting 130 km W.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666
m

The Nordic Volcanological Center (NVC) at the Institute of Earth

Sciences reported that on 9 June rumbling noises were heard at
Gígjökull just before a steam cloud rose from the summit crater. The
crater area was not visible the next day, but a few small shallow
earthquakes beneath the summit crater continued to be detected. On 11
June white steam was mainly confined to the crater, but occasionally a
steam plume rose higher than the rim. Heavy rainfall during the
previous few days led to flooding along the Svadbaelisa River. The
water contained a large amount of mud and flowed over levees into
fields. NVC also noted that a lake about 300 m in diameter had formed
in the large summit crater. Steam rose as high as 1 km from the rims,
especially from the N side. Two small vents above the water level on
the W side emitted brown-colored clouds.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is
located west of Katla volcano. Eyjafjallajökull consists of an E-W-
trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last
historical eruption of Eyjafjallajökull prior to an eruption in 2010
produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Source: Institute of Earth Sciences

Eyjafjallajökull Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

INSIVUMEH reported that during 10-11 June multiple explosions from
Fuego produced ash plumes that rose to altitudes of 4.1-4.3 km
(13,500-14,100 ft) a.s.l. and drifted NW. Rumbling and "degassing"
sounds were associated with the explosions. Occasionally incandescent
material was ejected as high as 75 m above the crater and avalanches
descended the flanks. Fine ashfall was reported in Sangre de Cristo,
10 km WSW. During a period of increased activity on 11 June, shock
waves were detected as far away as 5 km.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

Based on information from the Vanuatu Geohazards Observatory, the
Wellington VAAC reported that on 7 June an ash plume from Gaua rose to

an altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known

as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 4-11 June seismic activity from Karymsky
was above background levels, and suggested that possible ash plumes
rose to an altitude of 2.5 km (8,200 ft) a.s.l. on 6 June. Satellite
imagery revealed a thermal anomaly over the volcano during 4-5 and 8
June. Based on information from KVERT and Yelizovo Airport (UHPP), and
analyses of satellite imagery, the Tokyo VAAC reported that on 11 June
an eruption produced an ash plume that rose to an altitude of 6.1 km
(20,000 ft) a.s.l. and drifted NE and SE. The Aviation Color Code
level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 9-15 June HVO reported that activity at Kilauea continued from
the summit and the east rift zone. At the summit, the level of a lava-

pool surface remained mostly stable in the deep pit inset within the
floor of Halema'uma'u crater; glow from the vent was visible. A plume

from the vent mainly drifted SW, dropping small amounts of tephra
downwind. Vigorous bubbling of the lava surface was seen during 14-15
June.

At the east rift zone, lava flows that broke out of the TEB lava-tube
system at 580 m elevation built up rootless shields. Minor surface

lava flows from the shields were often active on the pali and the
coastal plain, and advanced along the W side of the TEB flow field
towards the abandoned Royal Gardens subdivision. The Pu'u 'O'o web
camera recorded a growing and sometimes circulating lava pond on the
crater floor that was an estimated 300 x 125 m in dimension. The pond
was fed predominantly from a source near the N rim of the Pu'u 'O'o,
with some contributions from a source near the S shore.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 4-11 June seismic activity from

Kliuchevskoi was above background levels and Strombolian activity was

seen. Gas-and-steam plumes, occasionally containing a small amount of
ash, were also noted. On 5 June ash plumes rose to an altitude of 7.3
km (24,000 ft) a.s.l. Satellite imagery revealed a large daily thermal
anomaly from the volcano, and ash plumes that drifted 60-190 km NE on
5 and 8 June. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 9-11 June steam-and-gas emissions from
Popocatépetl occasionally contained small amounts of ash. On 10 June
an ash-and-steam plume rose 800 m above the crater. The next day an
ash-and-gas plume rose 1 km above the crater. Later that day, another
ash-and-gas plume rose 600 m.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Sakura-jima during 12-14 June. Details of possible resulting plumes
were not reported. On 15 June an ash plume at an altitude of 3 km
(10,000 ft) a.s.l. was reported by a pilot.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 4-11 June seismic activity from Shiveluch
was above background levels and hot avalanches were seen at night. The
seismic data suggested that possible ash plumes rose to an altitude of
4.1 km (13,400 ft) a.s.l. during 3-4 and 6 June. Ash plumes were seen
during 4-6 and 9 June rising to an altitude of 4.5 km (14,800 ft)
a.s.l. Satellite imagery showed a large daily thermal anomaly over the
lava dome, and ash plumes that drifted 100 km SE on 4 June. The

Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that rockfalls and pyroclastic flows from the Soufrière
Hills lava dome occurred during 4-11 June. The largest pyroclastic
flow originated in the collapse scar and traveled 1 km N. The Hazard
Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

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wrote:

SI / USGS Weekly Volcanic Activity Report

16 June-22 June 2010

8 New+ 9 Ongoing = 17 active

Weekly Report Editor Sally Kuhn Sennert -

New Activity/Unrest:

| Etna, Sicily (Italy)
| Gorely, Southern Kamchatka (Russia)
| Ioto [Iwo-jima], Volcano Islands (Japan)

| Nevado del Huila, Colombia
| Pacaya, Guatemala

| Tiatia, Kunashir Island
| Tungurahua, Ecuador
| Ulawun, New Britain

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera

| Gaua, Banks Islands (SW Pacific)
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

New Activity/Unrest

ETNA Sicily (Italy) 37.734°N, 15.004°E; summit elev. 3330 m

INGV-CT reported a series of landslides on 19 June from the NW rim of
the pit crater located on the lower E side of Etna's Southeast Crater.
The collapses generated small ash clouds that drifted NE, and changed
the pit crater's morphology. Data from a thermal camera showed thermal
anomalies over 180 degrees Celsius indicating that the landslide
material was hot. Fumarolic activity was seen in the landslide area
during an inspection the day before.

Geologic Summary. Mount Etna, towering above Catania, Sicily's second
largest city, has one of the world's longest documented records of
historical volcanism, dating back to 1500 BC. Historical lava flows
cover much of the surface of this massive basaltic stratovolcano, the
highest and most voluminous in Italy. Two styles of eruptive activity
typically occur at Etna. Persistent explosive eruptions, sometimes
with minor lava emissions, take place from one or more of the three
prominent summit craters, the Central Crater, NE Crater, and SE
Crater. Flank eruptions, typically with higher effusion rates, occur
less frequently and originate from fissures that open progressively
downward from near the summit. A period of more intense intermittent
explosive eruptions from Etna's summit craters began in 1995. The
active volcano is monitored by the Instituto Nazionale di Geofisica e
Volcanologia (INGV) in Catania.

Map

Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di
Catania (INGV-CT)

Etna Information from the Global Volcanism Program

GORELY Southern Kamchatka (Russia) 52.558°N, 158.03°E; summit elev.
1829 m

KVERT reported that during 6 and 12-13 June strong steam-and-gas
activity from Gorely was noted, and during 11-18 June seismic activity
was above background levels. A small increase in the size and
temperature of a thermal anomaly over the volcano began on 15 June and
was detected through 18 June. The Level of Concern Color Code remained
at Green.

Geologic Summary. Gorely volcano, one of the most active in southern
Kamchatka, consists of five small overlapping stratovolcanoes
constructed along a WNW-ESE line within a large 9 x 13.5 km late-
Pleistocene caldera. The massive Gorely complex contains 11 summit and
30 flank craters. During the early Holocene, activity was
characterized by frequent mild eruptions with occasional larger
explosions and lava flows that filled in the caldera. Quiescent
periods became longer between 6,000 and 2,000 years ago, after which
the activity was mainly explosive. About 600-650 years ago
intermittent strong explosions and lava flow effusion accompanied
frequent mild eruptions. Historical eruptions have consisted of
vulcanian and phreatic explosions of moderate volume.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Gorely Information from the Global Volcanism Program

IOTO [IWO-JIMA] Volcano Islands (Japan) 24.754°N, 141.290°E; summit
elev. 161 m

Based on a pilot observation, the Tokyo VAAC reported that an ash
plume from Ioto (Iwo-jima) drifted more than 35 km N.

Geologic Summary. Ioto (also known as Iwo-jima) in the central Volcano
Islands portion of the Izu-Marianas arc lies within a 9-km-wide
submarine caldera. Ioto, Iwo-jima, and Io-jima are among many
transliterations of the name, which means "Sulfur Island;" the volcano
is also known as Ogasawara Io-jima to distinguish it from several
other "Sulfur Island" volcanoes in Japan. The triangular, low-
elevation, 8-km-long island narrows toward its SW tip and has produced
trachyandesitic and trachytic rocks that are more alkalic than those
of other Izu-Marianas arc volcanoes. The island has undergone dramatic
uplift for at least the past 700 years accompanying resurgent doming
of the caldera. A shoreline landed upon by Captain Cook's surveying
crew in 1779 is now 40 m above sea level. The Moto-yama plateau on the
NE half of the island consists of submarine tuffs overlain by coral
deposits and forms the island's high point. Many fumaroles are
oriented along a NE-SW zone cutting through Moto-yama. Numerous
historical phreatic eruptions, many from vents on the west and NW
sides of the island, have accompanied the remarkable uplift.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Ioto [Iwo-jima] Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

INGEOMINAS reported that during 9-15 June sulfur dioxide plumes from
Nevado del Huila were detected by multiple sources. A distinct change
in seismicity was noted on 13 June and was characterized by an
increased intensity and a greater number of hybrid earthquakes. These
earthquakes were shallow events beneath Pico Central. The Alert Level
was raised to II (Orange; "probable eruption in term of days or
weeks"). On 16 June two episodes of tremor possibly indicated ash
emissions; this was unconfirmed. However, sulfur dioxide plumes were
again detected. During 20-21 June small white pulsating fumarolic
plumes drifted W.

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Huila Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that during 16-22 June Pacaya's MacKenney cone
emitted white-and-blue fumarolic plumes that rose 50-400 m high. Ash
emissions were occasionally observed. INSIVUMEH also noted that the
lava flows on the SE flank were advancing more slowly and exhibited
fewer areas of incandescence.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

TIATIA Kunashir Island 44.351°N, 146.256°E; summit elev. 1819 m

SVERT reported that a thermal anomaly from Tiatia, a volcano on NE
Kunashir Island, was detected by satellite on 19 June. Tiatia does not

have a seismic network; satellite image observations are the primary

tool for monitoring many of the Kuril Islands volcanoes.

Geologic Summary. Tiatia volcano, one of the most impressive of the
Kuril Islands, consists of a beautifully symmetrical cone that rises
above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide
caldera. The 1819-m-high Tiatia (also known as Chacha-dake) occupies
the NE tip of Kunashir Island and morphologically resembles Mount
Vesuvius. The pristine-looking conical central cone, mostly formed by
basaltic to basaltic-andesite strombolian eruptions, rises 400 m above
the floor of the caldera and contains a 400 x 250 m wide crater with
two explosion vents separated by a linear septum. Fresh lava flows
cover much of the SW caldera floor and have overflowed the rim,
extending to the foot of the older somma, which formed during the late
Pleistocene or early Holocene. A lava flow from a flank cone on the
northern caldera rim reached the Sea of Okhotsk. A major explosive
eruption in 1973 was the first since Tiatia's initial historical
eruption in 1812.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Tiatia Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Although storm clouds occasionally prevented observations of

Tungurahua's summit area during 16-18 June, steam-and-ash plumes were
seen that rose to altitudes of 5.5-7 km (18,000-23,000 ft) a.s.l.
Daily reports of ashfall came from multiple areas about 8 km W and SW,
but ash was noted as far away as 15 km SW on 17 June. Ashfall in
Cahuají (8 km SW) covered pastureland, preventing animals from
grazing. Roaring noises were occasionally reported. During 17-18 June,
incandescence from the crater was seen at night. An explosion was
followed by roaring noises, sounds resembling blocks rolling down the
flanks, and incandescence.

On 19 June steam-and-ash plumes rose 500 m above the crater and large
windows vibrated after noises were heard. The next day snow covered
parts of the E and S flanks. Steam-and-gas plumes rose 500 m and
drifted SSW, E, and NW during 20-21 June. Lahars in drainages to the
SW carried blocks up to 50 cm in diameter. On 21 June ashfall was
reported in areas 8 km W.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that during 16-17 June white and gray plumes from Ulawun
rose 1 km high. Fine ash fell on the SW, W, and NW flanks. Low
rumbling noises were heard from the S and SE flanks, and weak
fluctuating incandescence was observed for a brief period of time. On
18 and 19 June, white-to-gray plumes rose from the crater, and roaring
noises were reported from the NW flank. Seismicity increased to a high
level and was dominated by volcanic tremor. During 19-20 June
continuing white and gray emissions produced plumes that rose 1 km.
Fine ashfall was seen on the NW and SW flanks. Fluctuating
incandescence was seen from the S and SE flanks and occasional low
roaring noises were noted. Seismicity declined to moderate levels on
20 June.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 19-20 June ash plumes from Batu Tara rose to an altitude of 3
km (10,000 ft) a.s.l. and drifted more than 35 km NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 18-20 June ash plumes from Dukono rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 120 km W.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m

Based on information from the Vanuatu Geohazards Observatory, the

Wellington VAAC reported that during 16-19 June ash plumes from Gaua
rose to an altitude of 3 km (10,000 ft) a.s.l. On 19 June the plume
drifted more than 90 km W.

Geologic Summary. The roughly 20-km-diameter Gaua Island, also known
as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with
an 6 x 9 km wide summit caldera. Small parasitic vents near the
caldera rim fed Pleistocene lava flows that reached the coast on
several sides of the island; several littoral cones were formed where
these lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash eruptions.
Construction of the historically active cone of Mount Garat (Gharat)
and other small cinder cones in the SW part of the caldera has left a
crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat
cone is topped by three pit craters. The onset of eruptive activity
from a vent high on the SE flank of Mount Garat in 1962 ended a long
period of dormancy.

Map

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Gaua Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 11-18 June seismic activity from Karymsky
was above background levels. Seismic data suggested that possible ash
plumes rose to an altitude of 5.2 km (17,000 ft) a.s.l. during 10-12
June and to an altitude of 3.9 km (12,800 ft) a.s.l. on 16 June.
Satellite imagery analysis revealed ash plumes that drifted about 195
km E on 10 and 11 June and a thermal anomaly over the volcano on 11,
15, and 16 June. Small ash clouds drifted 22 km E on 17 June. The

Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's

eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 16-22 June HVO reported that activity at Kilauea continued from

the summit and the east rift zone. At the summit, the level of a lava-

pool surface in the deep pit inset within the floor of Halema'uma'u
crater remained mostly stable; glow from the vent was also visible at
night. A plume from the vent mainly drifted SW, dropping small amounts
of tephra, and occasionally fresh spatter, downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube

system built up a number of rootless shields between 580 and 520 m
elevation. Satellite images showed thermal anomalies from minor lava
flows originating from the shields. The Pu'u 'O'o web camera views of
a lava pond on the crater floor, that was an estimated 300 x 150 m in
dimension, were often obscured by fumes. One small lava flow was seen
on the crater floor on 18 June. Scientists saw a new gas vent on the E
wall of the crater during an overflight on 21 June that had generated
incandescence during the previous few days.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 11-18 June seismic activity from

Kliuchevskoi was above background levels and Strombolian activity was

observed. Ashfall was reported in Klyuchi, 30 km NNE on 11 June. Ash
plumes occasionally rose to an altitude of 5.5 km (18,000 ft) a.s.l.
during 13-16 June. Satellite imagery analysis revealed a large daily
thermal anomaly from the volcano and ash plumes that drifted 40 km SE
on 13 and 15 June. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during
16-22 June explosions from Sakura-jima sometimes produced plumes.

Those plumes, along with ash plumes occasionally seen by pilots, rose

to altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l. According to a news
article, the JMA noted that two eruptions on 20 June brought the total
number of eruptions in 2010 to 550, setting a new annual record. The
total number of eruptions in 2009, the previous high at Sakura-jima,
was 548.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Japan Times

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 11-18 June seismic activity from Shiveluch
was above background levels and suggested that possible ash plumes
rose to an altitude of 4.9 km (16,100 ft) a.s.l. Strong fumarolic
activity and hot avalanches were seen on most days. Satellite imagery
showed a large daily thermal anomaly over the lava dome, and a small
anomaly near the lava dome on 15 June. The Aviation Color Code level
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that pyroclastic flows from the Soufrière Hills lava dome
occurred during 11-18 June. One of the largest pyroclastic flows
traveled W down Gages Valley; others originated from within the
collapse scar. A thermal camera showed several hot areas on the lava
dome, likely exposed from rockfall and pyroclastic flow activity. On
28 June a small lahar descended the Belham Valley, to the NW. The

leona...@gmail.com

unread,

Jul 1, 2010, 1:24:17 PM7/1/10

to

SI / USGS Weekly Volcanic Activity
Report

23 June-29 June 2010

4 New+ 9 Ongoing = 13 active

Weekly Report Editor Sally Kuhn Sennert -

New Activity/Unrest:

| Gorely, Southern Kamchatka (Russia)

| Pagan, Mariana Islands (Central Pacific)

| Tungurahua, Ecuador
| Ulawun, New Britain

Ongoing Activity:

| Dukono, Halmahera
| Eyjafjallajökull, Southern Iceland

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Kirishima, Kyushu

| Kliuchevskoi, Central
|Kamchatka (Russia)
| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

This page is updated on Wednesdays, please

New Activity/Unrest

GORELY Southern Kamchatka (Russia) 52.558°N, 158.03°E; summit elev.
1829 m

KVERT reported that during 17-25 June seismic activity from Gorely was
above background levels, and gas-and-steam plumes rose from the
crater. A volcanologist working at Gorely on 17 June saw that a new
vent had opened on the crater's inner SE wall, above the level of the
lake. The vent opening was incandescent, and gas was emitted at
temperatures of 800-900 degrees Celsius. Analysis of satellite imagery
showed a thermal anomaly over Gorely during 17-18 and 21-23 June;
cloud cover prevented observations on other days. The Level of
Aviation Color Code was raised to Yellow.

Geologic Summary. Gorely volcano, one of the most active in southern
Kamchatka, consists of five small overlapping stratovolcanoes
constructed along a WNW-ESE line within a large 9 x 13.5 km late-
Pleistocene caldera. The massive Gorely complex contains 11 summit and
30 flank craters. During the early Holocene, activity was
characterized by frequent mild eruptions with occasional larger
explosions and lava flows that filled in the caldera. Quiescent
periods became longer between 6,000 and 2,000 years ago, after which
the activity was mainly explosive. About 600-650 years ago
intermittent strong explosions and lava flow effusion accompanied
frequent mild eruptions. Historical eruptions have consisted of
vulcanian and phreatic explosions of moderate volume.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Gorely Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Minor gas-and-steam plumes from Pagan continued to be observed in
satellite imagery during 18-25 June. The Aviation Color Code remained
at Yellow and the Volcano Alert Level remained at Advisory.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana

Islands, Office of the Governor, United States Geological Survey
Volcano Hazards Program

Pagan Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Although storm clouds occasionally prevented observations of

Tungurahua's summit area, steam-and-gas plumes were seen on 22 and 23
June and steam-and-ash plumes were seen during 24-28 June. The plumes
rose as high as 1 km above the crater and drifted NW, W, and SW.
During most days ash fell in areas within 8 km SW and occasionally in
areas 8 km W and NW. Roaring noises were sometimes heard, and on 25
June were followed by vibrating windows 8 km W and SW. Lahars on 26
June traveled down drainages to the NW and W carrying blocks up to 2 m
in diameter. On 27 June ashfall was reported from areas 23 km NW and
25 km W. During 27-28 June incandescence emanated from the crater at
night.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that white-to-gray plumes rose from Ulawun during 23-25
June and fine ash fell on the SW and NW flanks. Low rumbling was heard
and dull fluctuating incandescence was observed for a brief period of
time from the SE. During 25-26 June white to gray-brown plumes rose
600 m. Seismicity, dominated by volcanic tremor, remained at a
moderate level until 26 June, when Real-time Seismic-Amplitude
Measurement (RSAM) values declined.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 23-24 and 29 June ash plumes from Dukono rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 120-225 km W.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666
m

The Nordic Volcanological Center (NVC) at the Institute of Earth

Sciences reported on 23 June that small ash clouds from
Eyjafjallajökull's summit caldera were occasionally seen, but
dispersed quickly. Water was slowly accumulating in the crater because
ice was no longer in contact with hot material.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is
located west of Katla volcano. Eyjafjallajökull consists of an E-W-
trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last
historical eruption of Eyjafjallajökull prior to an eruption in 2010
produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Source: Institute of Earth Sciences

Eyjafjallajökull Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

Based on analysis of satellite imagery, KVERT reported a thermal
anomaly over the volcano during 17, 19-20, and 22-23 June. Small ash
clouds 10 x 8 km and 12 x 5.5 km in dimension were seen E of the
volcano on 17 and 23 June, respectively. Based on information from
KEMSD, the Tokyo VAAC reported that an eruption on 29 June produced a
plume that rose to an altitude of 7 km (23,000 ft) a.s.l. Ash was not
identified on satellite imagery. The Aviation Color Code level
remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 23-29 June HVO reported that activity at Kilauea continued from

the summit and the east rift zone. At the summit, the level of a lava-
pool surface in the deep pit inset within the floor of Halema'uma'u
crater remained mostly stable; glow from the vent was also visible at
night. A plume from the vent mainly drifted SW, dropping small amounts
of tephra, and occasionally fresh spatter, downwind. At the east rift
zone, lava flows that broke out of the TEB lava-tube system built up a
number of rootless shields between 580 and 520 m elevation. Satellite
images showed thermal anomalies from minor lava flows originating from

the shields. The Pu'u 'O'o web camera showed incandescence from a vent
on the E wall of the crater.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KIRISHIMA Kyushu 31.931°N, 130.864°E; summit elev. 1700 m

Based on reports from JMA, the Tokyo VAAC reported a possible eruption
of Kirishima on 28 June. Information about a possible resulting plume
was not reported.

Geologic Summary. Kirishima is a large group of more than 20
Quaternary volcanoes located north of Kagoshima Bay. The late-
Pleistocene to Holocene volcano group consists of stratovolcanoes,
pyroclastic cones, maars, and underlying shield volcanoes located over
an area of 20 x 30 km. The larger stratovolcanoes are scattered
throughout the field, with the centrally located, 1,700-m-high
Karakuni-dake being the highest. Onami-ike and Mi-ike, the two largest
maars, are located SW of Karakuni-dake and at its far eastern end,
respectively. Holocene eruptions have been concentrated along an E-W
line of vents from Mi-ike to Ohachi, and at Shinmoe-dake to the NE.

Frequent small-to-moderate explosive eruptions have been recorded
since the 8th century.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Kirishima Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 18-25 June seismic activity from

Kliuchevskoi was above background levels and Strombolian activity was

sometimes observed. Ash plumes occasionally rose to an altitude of 5.5
km (18,000 ft) a.s.l. Satellite imagery analysis revealed a large
daily thermal anomaly from the volcano and ash plumes that drifted 120
km in multiple directions during 19 and 22-23 June. The Aviation Color

Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during

23-29 June explosions from Sakura-jima sometimes produced plumes.

Those plumes, along with ash plumes occasionally seen by pilots, rose

to altitudes of 1.8-3.7 km (6,000-12,000 ft) a.s.l. and drifted E, SE,
and NW.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 18-25 June seismic activity from Shiveluch

was above background levels and suggested that possible ash plumes

rose to an altitude of 5.1 km (16,700 ft) a.s.l. Strong fumarolic
activity and hot avalanches were observed during 21-23 June. An ash
plume was seen rising to an altitude of 6.5 km (21,300 ft) a.s.l. on
23 June. Satellite imagery showed a large daily thermal anomaly over
the lava dome and an ash cloud 5 x 5 km in dimension 30 km SE on 23

June. The Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

leona...@gmail.com

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Jul 8, 2010, 9:28:39 PM7/8/10

to

SI / USGS Weekly Volcanic Activity Report

30 June- 6 July 20 2010
4 New+ 12 Ongoing = 16 active

New Activity/Unrest:

| Ebeko, Paramushir Island
| Gorely, Southern Kamchatka (Russia)
| Tiatia, Kunashir Island
| Ulawun, New Britain

Ongoing Activity:

| Arenal, Costa Rica
| Bagana, Bougainville
| Dukono, Halmahera

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Kliuchevskoi, Central Kamchatka (Russia)
| Miyake-jima, Izu Islands (Japan)

| Pagan, Mariana Islands (Central Pacific)

| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

| Soufrière Hills, Montserrat
| Tungurahua, Ecuador

Weekly Report Editor Sally Kuhn Sennert -

This page is updated on Wednesdays, please

see the GVP Home Page for news of the
latest significantactivity.

        The Weekly VolcanicActivityReport is a
        cooperative project between the Smithsonian's
        Global Volcanism Program and the US
        Geological Survey'sVolcanoHazards Program.

        Updated by 2300 UTC every Wednesday,
        notices of volcanicactivityposted on these pages
        are preliminary and subject to change as events
        are studied in more detail.
        This is not a comprehensive list of all of Earth's

volcanos erupting during the week, but rather a

        summary of activity at volcanoes that meet
        criteria discussed in detail in the "Criteria and
        Disclaimers" section. Carefully reviewed,

detailed reports on various volcanos are

published monthly in the Bulletin of the Global
Volcanism Network.

        Note: Many news agencies do not archive the
        articles they post on the Internet, and therefore
        the links to some sources may not be active. To
          obtain information about the cited articles that
        are no longer available on the Internet contact
        the source.

New Activity/Unrest

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

KVERT reported that, according to observers in Severo-Kurilsk about 7
km E, activity from Ebeko increased on 2 July. Explosions produced ash
plumes that rose to an altitude of 1.8 km (5,900 ft) a.s.l. and
drifted SSE. The Level of Aviation Color Code was raised to Yellow.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Ebeko Information from the Global Volcanism Program

GORELY Southern Kamchatka (Russia) 52.558°N, 158.03°E; summit elev.
1829 m

KVERT reported that during 24 June-2 July seismic activity from Gorely
was above background levels, further increasing on 28 and 29 June.

Analysis of satellite imagery showed a thermal anomaly over Gorely

during 24-28 June; cloud cover prevented observations on other days. A
gas-and-steam plume drifted 35 km S on 28 June. The Level of Aviation

Color Code was raised to Yellow.

Geologic Summary. Gorely volcano, one of the most active in southern
Kamchatka, consists of five small overlapping stratovolcanoes
constructed along a WNW-ESE line within a large 9 x 13.5 km late-
Pleistocene caldera. The massive Gorely complex contains 11 summit and
30 flank craters. During the early Holocene, activity was
characterized by frequent mild eruptions with occasional larger
explosions and lava flows that filled in the caldera. Quiescent
periods became longer between 6,000 and 2,000 years ago, after which
the activity was mainly explosive. About 600-650 years ago
intermittent strong explosions and lava flow effusion accompanied
frequent mild eruptions. Historical eruptions have consisted of
vulcanian and phreatic explosions of moderate volume.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Gorely Information from the Global Volcanism Program

TIATIA Kunashir Island 44.351°N, 146.256°E; summit elev. 1819 m

SVERT reported that a thermal anomaly from Tiatia volcano was detected
by satellite on 25 June.

Geologic Summary. Tiatia volcano, one of the most impressive of the
Kuril Islands, consists of a beautifully symmetrical cone that rises
above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide
caldera. The 1819-m-high Tiatia (also known as Chacha-dake) occupies
the NE tip of Kunashir Island and morphologically resembles Mount
Vesuvius. The pristine-looking conical central cone, mostly formed by
basaltic to basaltic-andesite strombolian eruptions, rises 400 m above
the floor of the caldera and contains a 400 x 250 m wide crater with
two explosion vents separated by a linear septum. Fresh lava flows
cover much of the SW caldera floor and have overflowed the rim,
extending to the foot of the older somma, which formed during the late
Pleistocene or early Holocene. A lava flow from a flank cone on the
northern caldera rim reached the Sea of Okhotsk. A major explosive
eruption in 1973 was the first since Tiatia's initial historical
eruption in 1812.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Tiatia Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 1 and 2-5 July ash plumes from Ulawun drifted 55-195 km at an

altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun

stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during June activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian

eruptions, and occasional avalanches. Some of the Strombolian
eruptions caused glass to vibrate in buildings located 4 km N. A lava

flow that began in mid-January remained active on the S flank.

Avalanches from edges of the lava flow and from the N and NE crater
rim descended multiple flanks. Acid rain and small amounts of ejected
pyroclastic material affected the NE, E, and SE flanks. Small
explosions of gas and occasionally ash originated from a vent N of
Crater C, while Crater D produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft)
a.s.l. on 4 July and drifted 75 km W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 30 June-2 July and on 6 July ash plumes from Dukono rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted 90-225 km W and NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 25 June-2 July seismic activity from
Karymsky was above background levels and suggested that possible ash
plumes rose to an altitude of 7 km (23,000 ft) a.s.l. A strong thermal
anomaly was detected in satellite imagery on 27 June; cloud cover
prevented views of the volcano on other days. The Aviation Color Code
level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 30 June-6 July HVO reported that activity at Kilauea continued

from the summit and the east rift zone. At the summit, the level of a

lava-pool surface in the deep pit inset within the floor of

Halema'uma'u crater remained mostly stable; glow from the vent was
also visible at night. A plume from the vent mainly drifted SW,
dropping small amounts of tephra, and occasionally fresh spatter,
downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube

system built up a number of rootless shields between 580 and 395 m
elevation. Thermal anomalies detected in satellite images and visual
observations showed that minor lava flows originating from the shields
traveled as far down as 365 m elevation on 1 July. A gas vent on the E
wall of Pu'u 'O'o crater was incandescent during most of the reporting
period.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 25 June-2 July seismic activity from

Kliuchevskoi was above background levels and Strombolian activity was

observed on 24 and 29 June. Ash plumes occasionally rose to an
altitude of 5.3 km (17,400 ft) a.s.l. Satellite imagery analysis
revealed a large daily thermal anomaly from the volcano and an ash
plume that drifted 32 km S on 1 July. The Aviation Color Code level
remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

MIYAKE-JIMA Izu Islands (Japan) 34.079°N, 139.529°E; summit elev. 815
m

Based on information from JMA, the Tokyo VAAC reported a possible
eruption from Miyake-jima on 4 July. Details of possible resulting
plumes were unreported.

Geologic Summary. The circular, 8-km-wide island of Miyake-jima forms
a low-angle stratovolcano that rises about 1100 m from the sea floor
in the northern Izu Islands about 200 km SSW of Tokyo. Parasitic
craters and vents, including maars near the coast and radially
oriented fissure vents, dot the flanks of the volcano. Frequent
historical eruptions have occurred since 1085 AD at vents ranging from
the summit to below sea level, causing much damage on this small
populated island. After a three-century-long hiatus ending in 1469,
activity has been dominated by flank fissure eruptions sometimes
accompanied by minor summit eruptions. A 1.6-km-wide summit caldera
was slowly formed by subsidence during an eruption in 2000; by October
of that year the crater floor had dropped to only 230 m above sea
level.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Miyake-jima Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Minor gas-and-steam plumes from Pagan continued to be observed in

satellite imagery during breaks in cloud cover from 25 June to 2 July.
The Washington VAAC reported that on 5 July a small cloud of ash mixed
with a gas plume was observed in satellite imagery. The Aviation Color

Code remained at Yellow and the Volcano Alert Level remained at
Advisory.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Sources: Emergency Management Office of the Commonwealth of the

Mariana Islands, Office of the Governor, United States Geological

Survey Volcano Hazards Program, Washington Volcanic Ash Advisory
Center (VAAC)

Pagan Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 30
June-1 July and 4-6 July explosions from Sakura-jima sometimes

produced plumes. Those plumes, along with ash plumes occasionally seen

by pilots, rose to altitudes of 1.5-4.6 km (5,000-15,000 ft) a.s.l.
and drifted E and SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 24 June-2 July seismic activity from

Shiveluch was above background levels and suggested that possible ash

plumes occasionally rose to an altitude of 6.6 km (21,600 ft) a.s.l.
On 24 and 29 June ash plumes from hot avalanches rose to an altitude
of 4.5 km (14,800 ft) a.s.l. Strong fumarolic activity was also noted
on these days. On 1 July, seismicity increased and may have indicated
ash plumes rose to an altitude of 8 km (26,200 ft) a.s.l. Ashfall was
reported in Klyuchi village, 50 km SW. Satellite imagery showed a
large daily thermal anomaly over the lava dome. Based on analysis of
satellite imagery and information from Yelizovo Airport (UHPP), the
Tokyo VAAC reported that on 3 July an ash plume rose to an altitude of
6.1 km (20,000 ft) a.s.l. and drifted N. Satellite imagery showed a
possible eruption the next day. The Aviation Color Code level remained
at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

On 28 June, MVO reported that for the first time since February 2010
ash venting from the Soufrière Hills lava dome was observed and caused
light ashfall in several areas across Montserrat. Ash venting began on
25 June and was coincident with small swarms of volcano-tectonic
earthquakes on 23 and 25 June, although with no other discernable
associated seismicity. Observations initially from MVO staff and
during a later overflight indicated that the ash venting occurred from
inside the collapse scar (near the N rim of English's crater) and from
the S part of the summit crater that had formed on 11 February. On the
nights of 25 and 26 June audible roaring was heard from several
locations on the island. Ash venting diminished on 28 June. The Hazard
Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Observations of Tungurahua's summit area during 30 June-6 July were
mostly not possible due to inclement weather. On 2 July, gas plumes
were seen drifting WSW during breaks in the cloud cover. Ashfall was
reported in areas 8-9 km W and SW, and as far away as 40 km WSW in San
Juan. Incandescence from the crater was seen at night and slight
roaring was heard. Ashfall was again reported in areas 8-9 km W and SW
during 3-4 July. Steam-and-ash plumes were seen on 5 July and rose to
an altitude of 7 km (23,000 ft) a.s.l. Ash fell in areas 8 km to the
SW. Steam-and-ash plumes were again seen on 6 July; ashfall was
reported in areas 8 km W, NW, and N.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

leona...@gmail.com

unread,

Jul 14, 2010, 4:56:33 PM7/14/10

to aaron....@mail.mcgill.ca

SI / USGS
Weekly Volcanic Activity Report

7 July- 11 July 2010
2 New+ 10 Ongoing = 12 active

New Activity/Unrest:

| Soufrière Hills, Montserrat
| Stromboli, Aeolian Islands (Italy)

Ongoing Activity:

| Bagana, Bougainville
| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Kirishima, Kyushu
| Kliuchevskoi, Central Kamchatka (Russia)

| Pacaya, Guatemala | Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)

| Tungurahua, Ecuador
| Ulawun, New Britain

Weekly Report Editor Sally Kuhn Sennert -

         This page is updated on Wednesdays, please
         see the GVP Home Page for news of the
         latest significantactivity.

         The Weekly VolcanicActivityReport is a
         cooperative project between the Smithsonian's
         Global Volcanism Program and the US
         Geological Survey'sVolcanoHazards Program.

         Updated by 2300 UTC every Wednesday,
         notices of volcanicactivityposted on these pages
         are preliminary and subject to change as events
         are studied in more detail.
         This is not a comprehensive list of all of
Earth's

volcanoseruptingduring theweek, but rather a

         summary of activity at volcanoes that meet
         criteria discussed in detail in the "Criteria
and
         Disclaimers" section. Carefully reviewed,
            detailed reports on variousvolcanosare
         published monthly in the Bulletin of the Global
         Volcanism Network.

         Note: Many news agencies do not archive the
         articles they post on the Internet, and
therefore
         the links to some sources may not be active. To
           obtain information about the cited articles that
         are no longer available on the Internet contact
         the source.

New Activity/Unrest

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that small swarms of volcano-tectonic earthquakes from
Soufrière Hills on 23 and 25 June were coincident with ash venting
beginning on 25 June. Ash venting diminished on 28 June. A second
period of ash venting took place on 2 July and was preceded by two
volcano-tectonic and two long-period earthquakes. An emission of ash,
with accompanying rumbling noises, formed a plume that drifted WNW and
caused ashfall in uninhabited areas of Gages, Plymouth, and the Foxes
Bay region. During 2-9 July, roaring was often heard. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

STROMBOLI Aeolian Islands (Italy) 38.789°N, 15.213°E; summit elev. 924
m

INGV-CT reported that two major explosions from Stromboli were
detected by the seismic network. These explosions occurred from the SW
crater area on 25 June and from the NE crater area on 30 June. Poor
weather conditions prevented visual observations using the web camera
monitoring system. The event on 30 June was stronger, with several
explosions occurring in a short time. Fallout from incandescent blocks
triggered vegetation fires.

Geologic Summary. Spectacular incandescent nighttime explosions at
Stromboli volcano have long attracted visitors to the "Lighthouse of
the Mediterranean."Stromboli, the NE-most of the Aeolian Islands, has

lent its name to the frequent mild explosive activity that has

characterized its eruptions throughout historical time. The small, 926-
m-high island of Stromboli is the emergent summit of a volcano that
grew in two main eruptive cycles, the last of which formed the western
portion of the island. The active summit vents are located at the head
of the Sciara del Fuoco, a horseshoe-shaped scarp formed as a result
of slope failure that extends to below sea level and funnels
pyroclastic ejecta and lava flows to the NW. Essentially continuous

mild Strombolian explosions, sometimes accompanied by lava flows, have

been recorded at Stromboli since Roman times.

Map

Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di
Catania (INGV-CT)

Stromboli Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft)

a.s.l. and drifted 75-150 km SW during 10-11 July.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 7 and 9-10 July ash plumes from Dukono rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 35-75 km NW and N.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 2-9 July seismic activity from Karymsky was

above background levels and suggested that possible ash plumes rose to

an altitude of 2 km (6,500 ft) a.s.l. A thermal anomaly was detected
in satellite imagery on most days; cloud cover occasionally prevented
views of the volcano. On 7 July ash plumes drifted 20 km S. Based on
information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported
that on 13 July an ash plume rose to an altitude of 2.7 km (9,000 ft)
a.s.l. and drifted W. The Aviation Color Code level remained at
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 7-13 July HVO reported that activity at Kilauea continued from

the summit and the east rift zone. At the summit, the level of a lava-

pool surface in the deep pit within the floor of Halema'uma'u crater

remained mostly stable; glow from the vent was also visible at night.
A plume from the vent mainly drifted SW, dropping small amounts of

tephra downwind. At the east rift zone, lava flows that broke out of

the TEB lava-tube system built up a number of rootless shields between
580 and 395 m elevation. Thermal anomalies detected in satellite
images and visual observations showed that minor lava flows

originating from the shields traveled as far down as 60 m elevation
near the base of the pali on 11 July.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KIRISHIMA Kyushu 31.931°N, 130.864°E; summit elev. 1700 m

Based on reports from JMA, the Tokyo VAAC reported that an eruption
from the Kirishima volcanic complex on 10 July produced a plume that
rose to an altitude of 1.8 km (6,000 ft) a.s.l.

Geologic Summary. Kirishima is a large group of more than 20
Quaternary volcanoes located north of Kagoshima Bay. The late-
Pleistocene to Holocene volcano group consists of stratovolcanoes,
pyroclastic cones, maars, and underlying shield volcanoes located over
an area of 20 x 30 km. The larger stratovolcanoes are scattered
throughout the field, with the centrally located, 1,700-m-high
Karakuni-dake being the highest. Onami-ike and Mi-ike, the two largest
maars, are located SW of Karakuni-dake and at its far eastern end,
respectively. Holocene eruptions have been concentrated along an E-W
line of vents from Mi-ike to Ohachi, and at Shinmoe-dake to the NE.

Frequent small-to-moderate explosive eruptions have been recorded
since the 8th century.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Kirishima Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 2-9 July seismic activity from Kliuchevskoi
was above background levels. Satellite imagery analysis showed a large
daily thermal anomaly over the volcano and a gas-and-steam plume that
drifted 76 km S on 2 July. Ash plumes occasionally rose to an altitude
of 5.3 km (17,400 ft) a.s.l., and gas-and-steam activity was seen
during 2-4 July. According to a news article, lava flowed from a
fissure during 8-9 July. The Aviation Color Code level remained at
Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Itar-Tass

Kliuchevskoi Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 7 and 9 July, INSIVUMEH reported that white plumes rose from
Pacaya's MacKenney cone and drifted N. Small explosions were detected
by the seismic network on 7 July. According to a CONRED notice,
INSIVUMEH reported that an explosion on 13 July generated an ash plume
that rose 300 m above the crater and drifted SW. Ash and tephra fell
in nearby areas, and 150 people were evacuated.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Coordinadora Nacional para la Reducción de
Desastres (CONRED)

Pacaya Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on pilot observations, the Tokyo VAAC reported that on 7 and 9
July ash plumes from Sakura-jima rose to altitudes of 1.8-2.7 km
(6,000-9,000 ft) a.s.l. and drifted SE and NE. The VAAC also noted
that the JMA reported explosions during 11-13 July.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 2-9 July seismic activity from Shiveluch
was above background levels and suggested that on most days possible
ash plumes rose to an altitude of 7 km (22,900 ft) a.s.l. On 5 July
ash plumes from hot avalanches rose to an altitude of 4 km (13,100 ft)
a.s.l. and strong fumarolic activity was noted. Ashfall was observed
around the volcano. Satellite imagery showed a large daily thermal
anomaly over the lava dome and an ash plume that drifted 20 km S on 7
July. Tokyo VAAC reported that satellite imagery analyses indicated a
possible eruption on 10 July. The Aviation Color Code level remained
at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Observations of Tungurahua's summit area during 7-13 July were often
not possible due to inclement weather. On 7 July steam-and-ash plumes
rose to an altitude of 6 km (19,700 ft) a.s.l. and drifted WSW. The
next day explosions were accompanied by acoustic waves. A steam plume
rose to an altitude of 8 km (26,200 ft) a.s.l. and drifted NW. Ashfall
was reported in Cusúa about 8 km downwind. Incandescence from the
crater was seen during both nights. Ash-and-steam plumes were seen on
9 July. Ashfall was reported in a few areas 8 km SW and W. On 10 and
12 July plumes with low ash content drifted W. Ashfall was reported
7-8 km to the W and NNW on 12 July. Incandescent blocks descended the
flanks at night to 500 m below the crater on 9 and 12 July.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that white-to-gray plumes rose less than 500 m from
Ulawun during 27 June-9 July, and fine ash fell in areas to the SW, W,
and NW. Occasional roaring noises were heard on 28 June and during 5-6
July. A slight increase in seismicity (above moderate levels)
indicated by overlapping tremors and Real-time Seismic-Amplitude
Measurement (RSAM) values was noted during 5-8 July.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

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SI / USGS
Weekly Volcanic Activity Report

14 July-20 July 2010
   3 New+ 12 Ongoing = 15 active

New Activity/Unrest:

| Gorely, Southern Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Ubinas, Perú

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Fuego, Guatemala

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Kliuchevskoi, Central Kamchatka (Russia)
| Nevado del Ruiz, Colombia

| Pacaya, Guatemala
| Sakura-jima, Kyushu
| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)
| Tungurahua, Ecuador

Weekly Report Editor Sally Kuhn Sennert -

          This page is updated on Wednesdays, please
          see the GVP Home Page for news of the
          latest significant activity.

          The Weekly VolcanicActivityReport is a
          cooperative project between the Smithsonian's
          Global Volcanism Program and the US
          Geological Survey'sVolcanoHazards Program.

          Updated by 2300 UTC every Wednesday,
          notices of volcanicactivityposted on these pages
          are preliminary and subject to change as events
          are studied in more detail.
          This is not a comprehensive list of all of

Earths volcanos erupting during theweek, but

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Expanded detail omitted

New Activity/Unrest:

Ongoing Activity:

New Activity/Unrest

GORELY Southern Kamchatka (Russia) 52.558°N, 158.03°E; summit elev.
1829 m

KVERT reported that during 9-16 July seismic activity from Gorely was
above background levels,
and gas-and-steam emissions rose from the crater most days. On 10
July, data suggested that the
vent on the crater's inner NE wall, above the level of the lake, had
grown by 2-3 times the original
size. The lake level had also fallen. Analysis of satellite imagery

showed a thermal anomaly over

Gorely on 8, 10, 12, and 14 July, and gas-and-steam plumes that
drifted 25-150 km SE, E, and S
during 10 and 14-15 July. The Level of Aviation Color Code remained at
Yellow.

Geologic Summary. Gorely volcano, one of the most active in southern
Kamchatka, consists of five small overlapping stratovolcanoes
constructed along a WNW-ESE line within a large 9 x 13.5 km late-
Pleistocene caldera. The massive Gorely complex contains 11 summit and
30 flank craters. During the early Holocene, activity was
characterized by frequent mild eruptions with occasional larger
explosions and lava flows that filled in the caldera. Quiescent
periods became longer between 6,000 and 2,000 years ago, after which
the activity was mainly explosive. About 600-650 years ago
intermittent strong explosions and lava flow effusion accompanied
frequent mild eruptions. Historical eruptions have consisted of
vulcanian and phreatic explosions of moderate volume.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Gorely Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that activity at Soufrière Hills was low during 9-16
July. Helicopter observations on 15 July revealed no major changes to
the lava dome, although there were some fresh rockfall and small
pyroclastic-flow deposits at the head of the Gages valley to the W.
The next day, heavy rainfall generated a few lahars in the Belham
valley to the NW. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

Based on a pilot observation and analyses of satellite imagery, the
Buenos Aires VAAC reported that on 18 July an ash plume from Ubinas
drifted NE. A subsequent report about 12 hours later stated that no
further activity was seen.

Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of
Ubinas, Peru's most active volcano, gives it a truncated appearance.
Ubinas is the northernmost of three young volcanoes located along a
regional structural lineament about 50 km behind the main volcanic
front of Peru. The upper slopes of the stratovolcano, composed
primarily of Pleistocene andesitic lava flows, steepen to nearly 45
degrees. The steep-walled, 150-m-deep summit caldera contains an ash
cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-
avalanche deposits from the collapse of the SE flank of Ubinas extend
10 km from the volcano. Widespread Plinian pumice-fall deposits from
Ubinas include some of Holocene age. Holocene lava flows are visible
on the volcano's flanks, but historical activity, documented since the
16th century, has consisted of intermittent minor explosive eruptions.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Ubinas Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 18-20 July ash plumes from Batu Tara rose to an altitude of 1.5
km (5,000 ft) a.s.l. and drifted more than 35 km NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

INSIVUMEH reported on 19 July that six explosions from Fuego produced
ash plumes that rose to an altitude of 4.4 km (14,400 ft) a.s.l. and
drifted W and SW. Rumbling and "degassing" sounds were associated with
the explosions. Light ashfall was reported in Sangre de Cristo, 10 km
WSW. The seismic network had recorded a total of 17 explosions within
the previous 24 hours.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that satellite imagery showed ash plumes from Karymsky
drifting 30 km W and S on 7 and 8 July and a thermal anomaly over the
volcano during 8-10 and 12 July. Seismic activity was above background
levels during 12-14 July and suggested that possible ash plumes rose
to an altitude of 3.3 km (10,800 ft) a.s.l. Seismic data were not
available other days during 9-16 July due to technical problems. Based
on analyses of satellite imagery, the Tokyo VAAC reported that on 19
July a possible eruption produced a plume that rose to an altitude of
1.5 km (5,000 ft) a.s.l. and drifted SW. Ash was noted and then later
dissipated. A possible eruption was reported the next day, and again a
subsequent satellite image showed that ash had dissipated within a few
hours. The Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 14-20 July HVO reported that activity at Kilauea continued from

the summit and the east rift zone. At the summit, the level of a lava-
pool surface in the deep pit within the floor of Halema'uma'u crater
remained mostly stable; glow from the vent was also visible at night.

A plume from the vent mainly drifted SW. At the east rift zone, two
lava flows that broke out of the TEB lava-tube system advanced E
through the coastal highway 130/137 intersection beginning on 17 July,
and by 19 July were within 70 m of the nearest structure. A second set
of active lava lobes were approximately 1 km to the NW and also
advanced toward that general area. According to a news article, two
people evacuated their home in Kalapana due to advancing lava flows.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO),
Associated Press

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 9-16 July seismic activity from

Kliuchevskoi was above background levels. Satellite imagery analysis
showed a large daily thermal anomaly over the volcano and a gas-and-

ash plume that drifted 45 km NW on 14 July. Strombolian activity and
gas-and-ash emissions were observed during 9, 12, and 14-15 July. Ash
plumes occasionally rose to an altitude of 6.8 km (22,300 ft) a.s.l.
Based on analyses of satellite imagery and information from KVERT, the
Tokyo VAAC reported a possible eruption on 17 July. Ash was seen in
satellite imagery and then later dissipated. An eruption on 19 July
and a possible eruption the next day produced plumes that rose to
altitudes of 5.2-5.5 km (17,000-18,000 ft) a.s.l. and drifted SW and
SE. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL RUIZ Colombia 4.895°N, 75.322°W; summit elev. 5321 m

The Washington VAAC reported that a plume at an altitude of 7 km
(23,000 ft) a.s.l. from a possible eruption from Nevado del Ruiz on 17
July was stated in a Bogota MWO SIGMET notice. A second VAAC report
less than an hour later noted a brief seismic signal alert had been
issued and that meteorological cloud cover prevented observations of
the volcano. Ash was not seen in satellite imagery later that day nor
were there any additional reports of activity. [INGEOMINAS later
confirmed that no eruption had occurred.]

Geologic Summary. Nevado del Ruiz is a broad, glacier-covered volcano
in central Colombia that covers >200 sq km. Three major edifices,
composed of andesitic and dacitic lavas and andesitic pyroclastics,
have been constructed since the beginning of the Pleistocene. The
modern cone consists of a broad cluster of lava domes built within the
summit caldera of an older Ruiz volcano. The 1-km-wide, 240-m-deep
Arenas crater occupies the summit. Steep headwalls of massive
landslides cut the flanks of Nevado del Ruiz. Melting of its summit
icecap during historical eruptions, which date back to the 16th
century, has resulted in devastating lahars, including one in 1985
that was South America's deadliest eruption.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Ruiz Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that, after an increase in Pacaya's activity on 13
July, a decrease in seismicity was noted on 14 July. Strombolian
explosions occurred on 14 July at 5-10 minute intervals, and
occasional small pyroclastic flows traveled S. Gray ash plumes rose
500 m and drifted WSW. On 19 July, fumarolic plumes rose 100 m above
MacKenney crater and drifted N. The seismic network had recorded a
total of 120 explosions within the previous 24 hours. On 20 July
Strombolian explosions generated ash plumes that rose 100 m and
drifted 2 km N.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on JMA notices, the Tokyo VAAC reported explosions from Sakura-
jima on 14 and 20 July. During 15-18 July pilots observed ash plumes
that rose to altitudes of 1.8-3.4 km (6,000-11,000 ft) a.s.l. and
drifted NE, N, and NW. Plumes on 20 July rose as high as 2.1 km (7,000
ft) a.s.l. and drifted NW and N.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that 16 explosions from Santa María's Santiaguito
lava dome complex during 19-20 July produced ash plumes that rose
300-900 m above Santiaguito and drifted SE and W. Ashfall was reported
downwind in San José and La Quina. The seismic network had recorded a
total of 24 explosions within the 48 hour period.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 9-16 July seismic activity from Shiveluch
was above background levels and suggested that possible ash plumes
rose to an altitude of 4.3 km (12,100 ft) a.s.l. Satellite imagery
showed a large daily thermal anomaly over the lava dome. Gas-and-steam
plumes were seen rising to an altitude of 3.7 km (12,100 ft) a.s.l.
during 9 and 11-14 July. Based on analysis of satellite imagery, the
Tokyo VAAC reported a possible eruption on 19 July. Ash was seen in
subsequent satellite images and then later dissipated. The Aviation

Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima on 17 and 19 July. Details of possible resulting plumes
were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Observations of Tungurahua's summit area during 13-20 July were
sometimes not possible due to inclement weather. On 13 July
incandescent blocks were seen rolling down the flanks at night and
ashfall was reported in areas 8 km SW. Incandescence from the crater
was seen the next night and ashfall was again reported in areas to the
SW. During 15-18 July steam-and-ash plumes were observed and
occasionally drifted SW. Ashfall was noted in areas within 8 km SW, W,
and NW. Lahars descended drainages to the SW, NW, and N on 15 July.
Rolling blocks on the flanks were seen after explosions on 18 July.
During 19-20 July steam plumes drifted NW and W.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

Global Volcanism Program — Department of Mineral Sciences

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SI / USGS
Weekly Volcanic Activity Report

21 July - 27 July 2010
    5 New+ 14 Ongoing = 19 active

New Activity/Unrest:

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Chaitén, Southern Chile

| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)

| Kliuchevskoi, Central Kamchatka (Russia)
| Pacaya, Guatemala
| Sakura-jima, Kyushu

| Sangay, Ecuador
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)
| Tungurahua, Ecuador

| Turrialba, Costa Rica
| Ulawun, New Britain

New Activity/Unrest

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

On 23 July, KVERT reported that the Aviation Color Code level for
Ebeko was lowered to Green. Visual observations and satellite data
indicated no activity from the volcano during 16-23 July.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Ebeko Information from the Global Volcanism Program

GORELY Southern Kamchatka (Russia) 52.558°N, 158.03°E; summit elev.

1829 m

KVERT reported that during 16-23 July seismic activity from Gorely was
above background levels and volcanic tremor continued to be detected.
Gas-and-steam activity was noted daily and many new small fumarolic
vents were seen in the active crater. The temperature of a daily
thermal anomaly detected over the volcano in satellite imagery
gradually increased from 29 to 46 degrees Celsius during 17-21 July.
The Aviation Color Code level remained at Yellow.

Geologic Summary. Gorely volcano, one of the most active in southern
Kamchatka, consists of five small overlapping stratovolcanoes
constructed along a WNW-ESE line within a large 9 x 13.5 km late-
Pleistocene caldera. The massive Gorely complex contains 11 summit and
30 flank craters. During the early Holocene, activity was
characterized by frequent mild eruptions with occasional larger
explosions and lava flows that filled in the caldera. Quiescent
periods became longer between 6,000 and 2,000 years ago, after which
the activity was mainly explosive. About 600-650 years ago
intermittent strong explosions and lava flow effusion accompanied
frequent mild eruptions. Historical eruptions have consisted of
vulcanian and phreatic explosions of moderate volume.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Gorely Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 21-27 July HVO reported that activity at Kilauea continued from

the summit and the east rift zone. At the summit, the level of a lava-
pool surface in the deep pit within the floor of Halema'uma'u crater
remained mostly stable; glow from the vent was also visible at night.

A plume from the vent mainly drifted SW.

At the east rift zone, lava flows that broke out of the TEB lava-tube

system advanced E and NE along coastal highway 137 beginning on 17
July and expanded S, filling in the area between the highway and the N-
facing scarp of the Hakuma horst. On 24 July, lava flowed N and by the
next morning had destroyed a home in Kalapana Gardens. Advancing lava
flowed over an area of the horst and on 25 July reached the ocean. On
26 July, lava caused small brush fires and methane explosions in a
kipuka on the W edge of the Kalapana subdivision. By 1200 on 27 July,
a second lava flow 500 m E of the ocean entry had advanced over the
horst and was about 20 m from the ocean. At Pu'u 'O'o crater,
intermittent incandescence from lava flows on the N crater floor was
visible starting on 24 July.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

MIYAKE-JIMA Izu Islands (Japan) 34.079°N, 139.529°E; summit elev. 815
m

Based on information from JMA, the Tokyo VAAC reported that an
eruption from Miyake-jima on 21 July produced a plume that rose to an
altitude of 1.2 km (4,000 ft) a.s.l. and drifted E.

Geologic Summary. The circular, 8-km-wide island of Miyake-jima forms
a low-angle stratovolcano that rises about 1100 m from the sea floor
in the northern Izu Islands about 200 km SSW of Tokyo. Parasitic
craters and vents, including maars near the coast and radially
oriented fissure vents, dot the flanks of the volcano. Frequent
historical eruptions have occurred since 1085 AD at vents ranging from
the summit to below sea level, causing much damage on this small
populated island. After a three-century-long hiatus ending in 1469,
activity has been dominated by flank fissure eruptions sometimes
accompanied by minor summit eruptions. A 1.6-km-wide summit caldera
was slowly formed by subsidence during an eruption in 2000; by October
of that year the crater floor had dropped to only 230 m above sea
level.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Miyake-jima Information from the Global Volcanism Program

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported an eruption from Rabaul caldera's Tavurvur cone on 23
July, after increased seismicity likely beneath Tavurvur cone was
detected the previous day. The eruption was preceded by a few small
hybrid earthquakes at 1034 followed by small low-frequency earthquakes
and later continuous volcanic tremor. Diffuse white plumes were
initially emitted at 1320, and then pink-gray fumes with low ash
content were seen. A strong odor of hydrogen sulfide was noted, and a
diffuse cloud rose 1 km and drifted NW. Billowing gray clouds a few
hours later (at 1600) indicated a higher ash content and increased
activity. They were also accompanied by roaring and rumbling noises.
Discrete explosions commenced at 1730. Ashfall was reported in areas
to the NW and NNW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the
Gazelle Peninsula at the NE end of New Britain forms a broad sheltered
harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic
shield volcano are formed by thick pyroclastic-flow deposits. The 8 x
14 km caldera is widely breached on the E, where its floor is flooded
by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul
took place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims. Post-
caldera eruptions built basaltic-to-dacitic pyroclastic cones on the
caldera floor near the NE and western caldera walls. Several of these,
including Vulcan cone, which was formed during a large eruption in
1878, have produced major explosive activity during historical time. A
powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.

Map

Source: Rabaul Volcano Observatory (RVO)

Rabaul Information from the Global Volcanism Program

Ongoing Activity
——————————

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.

748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 21 July an ash plume from Batu Tara drifted 55 km NW at an altitude
of 1.5 km (5,000 ft) a.s.l.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on analyses of satellite imagery, the Buenos Aires VAAC reported
that an ash plume from Chaitén's lava-dome complex drifted 70 km SSE
on 24 July. Meteorological cloud cover in subsequent images prevented
further detection of the plume.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. Obsidian
cobbles from this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the Pacific
coast as far as 400 km away from the volcano to the north and south.
The caldera is breached on the SW side by a river that drains to the
bay of Chaitén, and the high point on its southern rim reaches 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 24 July an ash plume from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted over 110 km W.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 16-23 July seismic activity from Karymsky

was above background levels and suggested that possible ash plumes

rose to an altitude of 3 km (9,800 ft) a.s.l. A daily thermal anomaly
was detected in satellite imagery. Imagery also showed ash plumes that
drifted 58 km SW on 19 July and 85 km SE on 21 July. The Aviation

Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's

eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 16-23 July seismic activity from

Kliuchevskoi was above background levels and Strombolian activity was

seen. Gas-and-steam activity was noted with ash plumes periodically
rising to an altitude of 6.3 km (20,700 ft) a.s.l. Effusive lava flows
descended the SSW flank. Satellite imagery analysis showed a large

daily thermal anomaly from the volcano and ash plumes that drifted

about 55-160 km SW, SE, and NE. The Aviation Color Code level remained
at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that on 20 July Strombolian explosions from
Pacaya's MacKenney cone ejected ash that fell in neighboring areas.
During 20-21 July there were 90 explosions recorded by the seismic
network. Based on information from INSIVUMEH, the Washington VAAC
reported that on 22 July a plume rose to an altitude of 4.6 km (15,000
ft) a.s.l. and drifted N. A weak thermal anomaly was seen in
subsequent images. The next day, ash plumes drifted N at an altitude
of 4.1 km (13,500 ft) a.s.l. and produced ashfall in areas within 10
km. On 25 July, INSIVUMEH noted that Strombolian explosions ejected
tephra 100 m above the crater, and generated ash plumes that rose 300
m above the crater and drifted 10 km SW. Ejected blocks fell onto the
flanks.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,

e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Pacaya Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during
21-27 July explosions from Sakura-jima produced plumes. Those plumes,

along with ash plumes occasionally seen by pilots, rose to altitudes

of 1.2-4.6 km (4,000-15,000 ft) a.s.l. Most plumes rose vertically
while others drifted N and NW.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on pilot observations and analyses of satellite imagery, the
Washington VAAC reported that on 21 July an ash cloud from Sangay
drifted W. During 22-23 July, diffuse plumes drifted 65-115 km W.
Occasional thermal anomalies were detected by satellite imagery on 21
and 23 July.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 16-23 July seismic activity from Shiveluch
was above background levels, possibly indicating weak ash explosions
from the lava dome. According to visual observations, gas-and-steam
plumes rose daily to an altitude of 3.7 km (12,100 ft) a.s.l. and ash
plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. on 20 and 21
July. Satellite imagery showed a large daily thermal anomaly over the
lava dome and ash plumes that drifted 50 km NE on 21 July. The

Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that activity at Soufrière Hills was low during 16-23
July and inclement weather prevented clear observations of the lava
dome. Heavy rains generated a few lahars in the Belham valley to the
NW. The largest occurred on 20 July and lasted about 40 minutes. The

Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Suwanose-jima produced plumes that rose to an altitude of 1.5 km
(5,000 ft) a.s.l. on 23 July and to an altitude of 2.4 km (8,000 ft)
a.s.l. on 26 July. Plumes drifted NW and W, respectively.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Observations of Tungurahua's summit area during 21-27 July were
sometimes not possible due to inclement weather. Ash plumes seen
during 21-23 July rose to altitudes of 6-9 km (19,700-29,500 ft)
a.s.l. and drifted W and NW. Ashfall was reported in areas within 10
km NW, W, and SW during 22-24 July. Steam plumes were seen rising 200
m above the crater on 25 July and an explosion was heard on 26 July.
On 27 July a series of explosions was detected by the seismic network.
Roaring noises were followed by vibrating windows in areas to the N
and NW. Slight ashfall was noted in areas to the SW and W, and as far
as 23 km NW.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito,
Ecuador's capital city, and is one of Ecuador's most active volcanoes.
Historical eruptions have all originated from the summit crater. They
have been accompanied by strong explosions and sometimes by
pyroclastic flows and lava flows that reached populated areas at the
volcano's base. The last major eruption took place from 1916 to 1918,
although minor activity continued until 1925. The latest eruption
began in October 1999 and prompted temporary evacuation of the town of
Baños on the N side of the volcano.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

Based on web camera views of Turrialba, the Washington VAAC reported
that on 24 July a plume of steam, gas, and ash drifted W. Over the
next three hours the plume became more diffuse and steam-rich.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Turrialba Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that diffuse gray plumes rose 200-500 m above Ulawun
during 16-21 July. Volcanic tremors continued, but overall seismicity
declined slightly. Real-time Seismic-Amplitude Measurement (RSAM)
values remained at a moderate level.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.

Map

Source: Rabaul Volcano Observatory (RVO)

Ulawun Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

Global Volcanism Program — Department of Mineral Sciences

leona...@gmail.com

unread,

Aug 15, 2010, 10:16:10 PM8/15/10

to

SI / USGS
Weekly Volcanic Activity Report

   4 August-10 August 2010
     2 New+ 7 Ongoing = 9 active

New Activity/Unrest:

| Karangetang [Api Siau], Siau I
| Kilauea, Hawaii (USA)

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Karymsky, Eastern Kamchatka (Russia)
| Kliuchevskoi, Central Kamchatka (Russia)

| Sakura-jima, Kyushu
| Santa María, Guatemala

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

Weekly Report Editor Sally Kuhn Sennert -

New Activity/Unrest

KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m

According to news articles, an eruption from Karangetang on 6 August
produced pyroclastic flows on the W flank that destroyed at least
seven houses. A hot ash plume rose above the crater, and incandescent
material was ejected from the crater and descended multiple flanks. At
least four people were missing, five were injured, and about 65 were
evacuated. An article also stated that CVGHM raised the Alert Level to
3 (on a scale of 1-4). According to reports from CVGHM and analyses of
satellite imagery, the Darwin VAAC reported that an ash plume rose to
an altitude of 9.1 km (30,000 ft) a.s.l. and drifted W.

Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi, and contains five
summit craters strung along a N-S line. One of Indonesia's most active
volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Sources: Darwin Volcanic Ash Advisory Centre (VAAC), CNN, Associated
Press

Karangetang [Api Siau] Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 4-10 August HVO reported that activity at Kilauea continued
from the summit caldera and the east rift zone. At the summit caldera,
the level of a lava-pool surface in the deep pit within the floor of

Halema'uma'u crater remained mostly stable; glow from the vent was

also visible at night. A plume from the vent mainly drifted SW,
dropping small amounts of ash downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube

system fed surface flows on the coastal plain, an inflating surface
flow in Kalapana, and two ocean entries. The delta built by the W
ocean entry named Puhi-o-Kalaikini was 900 m wide by 8 August. The
less vigorous E entry, 'Ili'ili, remained active until 9 August. At
Pu'u 'O'o crater, incandescence from small areas on the N crater floor
was visible. During 9-10 August minor spattering from the area built a
very small cone.

Geologic Summary. Kilauea, one of five coalescing volcanos that

comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the
summit caldera or along one of the lengthy E and SW rift zones
that extend from the caldera to the sea. About 90% of the surface
of Kilauea is formed of lava flows less than about 1,100 years old;
70% of the volcano's surface is younger than 600 years. A long-
term eruption from the East rift zone that began in 1983 has
produced lava flows covering more than 100 sq km, destroying
nearly 200 houses and adding new coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 9-10 August ash plumes from Batu Tara drifted NW and SW at an

altitude of 1.5 km (5,000 ft) a.s.l.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 30 July-6 August seismic activity from

Karymsky was above background levels and suggested that possible ash

plumes rose to an altitude of 2 km (6,700 ft) a.s.l. A thermal anomaly
over the volcano was detected in satellite imagery during 29-30 July
and 1-2 and 4 August. Imagery also showed ash plumes that drifted 17
km NE on 2 and 3 August. The Aviation Color Code level remained at
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that 30 July-6 August seismic activity from
Kliuchevskoi was above background levels and lava flowed down the SSE
flank. Strombolian activity and gas-and-ash emissions were observed
during 29-30 July and 4-5 August. Cloud cover prevented observations
the other days. Satellite imagery analysis showed a large daily
thermal anomaly from the volcano and a gas-and-ash plume that drifted
65 km NW on 30 July. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Sakura-jima during 4-9 August produced plumes that rose to
altitudes of 1.2-2.4 km (4,000-8,000 ft) a.s.l. and drifted W, NW, and
N. Pilots observed ash plumes that rose to altitudes of 2.1-3 km
(7,000-10,000 ft) a.s.l. on 7, 9, and 10 August.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 5 August, INSIVUMEH reported that lahars descended Santa María's
Nima I, Nima II, and San Isidro rivers, carrying tree branches as well
as blocks up to 2 m in diameter. The next day, steam plumes rose above
Caliente dome and drifted SW.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 30 July-6 August seismic activity from
Shiveluch was above background levels and suggested that possible ash
plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. Gas-and-steam
plumes were seen rising to an altitude of 4 km (13,100 ft) a.s.l.
during 29-31 July. Cloud cover prevented observations the other days.
Satellite imagery analysis showed a large daily thermal anomaly on the
volcano. Based on analysis of satellite imagery, the Tokyo VAAC
reported that an eruption on 9 August produced a plume that rose to an
altitude of 6.7 km (22,000 ft) a.s.l. The Aviation Color Code level
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

Based on a METAR weather report and analyses of satellite imagery, the
Washington VAAC reported that on 10 August a narrow plume from
Soufrière Hills drifted more than 100 km WNW.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Soufrière Hills Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

leona...@gmail.com

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Aug 19, 2010, 12:53:09 PM8/19/10

to

SI / USGS
Weekly Volcanic Activity Report

   11 Aug - 17 Aug 2010
     3 New+ 10 Ongoing = 13 active

New Activity/Unrest:

| Kilauea, Hawaii (USA)
| Manam, Northeast of New Guinea (SW Pacific)
| San Miguel, El Salvador

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)

| Dukono, Halmahera
| Fuego, Guatemala

| Karymsky, Eastern Kamchatka (Russia)
| Kliuchevskoi, Central Kamchatka (Russia)

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Turrialba, Costa Rica
| Ulawun, New Britain

Weekly Report Editor Sally Kuhn Sennert -

            This page is updated on Wednesdays, please
            see the GVP Home Page for news of the
            latest significant activity.

            The Weekly VolcanicActivityReport is a
            cooperative project between the Smithsonian's
            Global Volcanism Program and the US
            Geological Survey'sVolcanoHazards Program.

            Updated by 2300 UTC every Wednesday,
            notices of volcanicactivityposted on these pages
            are preliminary and subject to change as events
            are studied in more detail.
            This is not a comprehensive list of all of

Earths volcanoseruptingduring theweek, but

   rather a summary of activity at volcanoes that
   meet criteria discussed in detail in the "Criteria
   and Disclaimers" section. Carefully reviewed,
            detailed reports on variousvolcanosare
            published monthly in the Bulletin of the
            Global Volcanism Network.

            Note: Many news agencies do not archive the
            articles they post on the Internet, and therefore
            the links to some sources may not be active. To
           obtain information about the cited articles that
            are no longer available on the Internet contact
            the source.

New Activity/Unrest

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 11-17 August HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,

the level of the lava-pool surface in the deep pit within the floor of

Halema'uma'u crater remained mostly stable; glow from the vent was

also visible at night. A plume from the vent mainly drifted SW,
dropping small amounts of ash downwind. At Pu'u 'O'o crater, a small
incandescent vent on the N floor that occasionally extruded lava flows
was observed to be a hornito. At the east rift zone, lava that flowed
through the TEB lava-tube system fed occasional surface flows at the
base of the pali and on the coastal plain WNW and W of Kalapana
Gardens, as well as the Puhi-o-Kalaikini ocean entry.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

RVO reported that incandescence from Manam's South Crater was visible
at 4-5 minute intervals on 10 August. The next day diffuse black ash
plumes rose a few hundred meters above the rim. Steady incandescence
was accompanied by periodic ejections of lava fragments ejected
400-500 m above the rim. Main Crater emitted diffuse white vapor.
Based on analysis of satellite imagery, the Darwin VAAC reported that
on 14 August ash plumes rose to an altitude of 2.4 km (8,000 ft)
a.s.l. and drifted 55 km NW.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Manam Information from the Global Volcanism Program

SAN MIGUEL El Salvador 13.434°N, 88.269°W; summit elev. 2130 m

On 13 August, Servicio Nacional de Estudios Territoriales (SNET)
reported that seismicity remained above background levels after an
increase was detected on 1 August. Average background RSAM values
ranged from 15 to 50 units per day. During 12-13 August, RSAM values
ranged between 433 and 465. Over the next few days, seismicity
decreased significantly; from 14 August to 16 August, RSAM values
decreased from 188 to 132. Access to areas within a 2-km-radius
remained restricted.

Geologic Summary. The symmetrical cone of San Miguel volcano, one of
the most active in El Salvador, rises from near sea level to form one
of the country's most prominent landmarks. A broad, deep crater that
has been frequently modified by historical eruptions (recorded since
the early 16th century) caps the truncated summit of the towering
volcano, which is also known locally as Chaparrastique. Radial
fissures on the flanks of the basaltic volcano have fed a series of
fresh lava flows, including several erupted during the 17th-19th
centuries that reached beyond the base of the volcano on the N, W, and
SE sides. The SE-flank lava flows are the largest and form broad
sparsely vegetated lava fields.

Map

Source: Servicio Nacional de Estudios Territoriales (SNET)

San Miguel Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 13-15 August ash plumes from Bagana rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 75 km SW and W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 13-17 August ash plumes from Batu Tara drifted 35-95 km NW and
W at altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 12-17 August ash plumes from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 25-95 km W, NW, and SW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

During 12-17 August, INSIVUMEH reported that explosions from Fuego
produced ash plumes that rose to altitudes of 4.1-4.7 km
(13,500-15,400 ft) a.s.l. and drifted W and NW. Rumbling and
"degassing" sounds were associated with the explosions. At night
during 15-16 August explosions ejected incandescent material 100 m
above the crater. On 17 August blocks descended the S flanks.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 6-13 August seismic activity from Karymsky

was above background levels and suggested that possible ash plumes

rose to an altitude of 2.5 km (8,200 ft) a.s.l. A thermal anomaly over
the volcano was detected in satellite imagery during 7-8 and 10-11
August. Based on analyses of satellite imagery and information from
KVERT, the Tokyo VAAC reported an eruption on 16 August. A subsequent
notice stated that ash had dissipated. The Aviation Color Code level
remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 6-13 August seismic activity from
Kliuchevskoi was above background levels and lava flowed down the SW

flank. Strombolian activity and gas-and-ash emissions were observed

during 6 and 8-12 August. Cloud cover prevented observations the other
days. Satellite imagery analysis showed a large and intense daily
thermal anomaly on the volcano. Based on analyses of satellite
imagery, the Tokyo VAAC reported a possible eruption on 16 August. A
subsequent notice stated that ash had dissipated. The Aviation Color

Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 6-13 August seismic activity from Shiveluch
was above background levels, suggesting that possible ash plumes rose
to an altitude of 6.5 km (21,300 ft) a.s.l. on 9 August and to an
altitude of 4 km (13,100 ft) a.s.l. the other days. Cloud cover
prevented visual observations. Satellite imagery analysis showed a
daily thermal anomaly on the volcano and an ash plume that drifted 55
km NW on 10 August. The Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that mild ash-and-steam venting from Soufrière Hills as
well as rockfalls were seen during 6-13 August. Most of the activity
was focused in the collapse scar and above the Gages valley to the W.
On 6 August a small ash plume rose 1 km above the lava dome, and on 8
August a pyroclastic flow descended Gages valley. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m

The Washington VAAC reported that on 15 August ash emissions from
Turrialba were seen through an OVSICORI-UNA web camera, about 600 m E
of the active crater. Satellite imagery showed an approximately 10-km-
wide ash plume drifting 15 km W.

Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano
located across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in height
only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's
most voluminous volcanoes. Three well-defined craters occur at the
upper SW end of a broad 800 x 2200 m wide summit depression that is
breached to the NE. Most activity at Turrialba originated from the
summit vent complex, but two pyroclastic cones are located on the SW
flank. Five major explosive eruptions have occurred at Turrialba
during the past 3500 years. Turrialba has been quiescent since a
series of explosive eruptions during the 19th century that were
sometimes accompanied by pyroclastic flows. Fumarolic activity
continues at the central and SW summit craters.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Turrialba Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that white and gray-to-brown plumes rose no more than 300
m above Ulawun during 6-12 August, and fine ash fell on the NW and W
flanks. Seismicity decreased as compared to previous weeks.

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Aug 25, 2010, 9:43:11 PM8/25/10

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SI / USGS
Weekly Volcanic Activity Report

    18 August-24 August 2010
      1 New+ 15 Ongoing = 16 active

New Activity/Unrest:

| Galeras, Colombia

Ongoing Activity:

| Ambrym, Vanuatu (SW Pacific)

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Pagan, Mariana Islands (Central Pacific)

| Popocatépetl, México
| Sakura-jima, Kyushu
| San Cristóbal, Nicaragua
| Sangay, Ecuador

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)
| Ulawun, New Britain

Ongoing Activity:

New Activity/Unrest

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

INGEOMINAS reported that an earthquake swarm from Galeras which began
on 20 August had been preceded by increased gas emissions a few days
prior. During 21-22 August seismicity remained high. Five volcano-
tectonic earthquakes were felt by local residents and caused windows
to vibrate. They were located within a 300-900 m radius from the
crater, at depths of less than 2 km. The largest event was M 4.3. On
23 August a M 4.6 earthquake was located E of Galeras at a depth of 2
km. The Alert Level was raised to II (Orange; "probable eruption in
term of days or weeks"). An eruption began on 25 August, prompting
INGEOMINAS to raise the Alert Level to I (Red; "imminent eruption or
in progress"). Meteorological cloud cover initially prevented visual
observations of the summit, although an eruption plume was seen
amongst the clouds, and thermal anomalies were detected by an infrared
camera. Ashfall was reported in areas 7-12 km NW. Observers in Pasto
(~ 10 km E) reported that gas-and-ash plumes rose 300 m above the
crater.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Galeras Information from the Global Volcanism Program

Ongoing Activity

AMBRYM Vanuatu (SW Pacific) 16.25°S, 168.12°E; summit elev. 1334 m

Based on pilot observations, analyses of satellite imagery, and

information from the Vanuatu Geohazards Observatory, the Wellington

VAAC reported that on 8 and 10 August ash-and-steam plumes from Ambrym
rose to an altitude 6.1 km (20,000 ft) a.s.l. and drifted W and NW.

Geologic Summary. Ambrym, a large basaltic volcano with a 12-km-wide
caldera, is one of the most active volcanoes of the New Hebrides arc.
A thick, almost exclusively pyroclastic sequence, initially dacitic,
then basaltic, overlies lava flows of a pre-caldera shield volcano.
The caldera was formed during a major Plinian eruption with dacitic
pyroclastic flows about 1900 years ago. Post-caldera eruptions,
primarily from Marum and Benbow cones, have partially filled the
caldera floor and produced lava flows that ponded on the caldera floor
or overflowed through gaps in the caldera rim. Post-caldera eruptions
have also formed a series of scoria cones and maars along a fissure
system oriented ENE-WSW. Eruptions have apparently occurred almost
yearly during historical time from cones within the caldera or from
flank vents. However, from 1850 to 1950, reporting was mostly limited
to extra-caldera eruptions that would have affected local populations.

Map

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Ambrym Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 20-23 August ash plumes from Batu Tara drifted 25-65 km NW and
W at an altitude of 1.5 km (5,000 ft) a.s.l.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 18-22 August ash plumes from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 65-225 km W and NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 13-20 August seismic activity from Karymsky

was above background levels and suggested that possible ash plumes

rose to an altitude of 3 km (9,800 ft) a.s.l. Satellite imagery showed
a thermal anomaly over the volcano during 14-15 August and ash plumes
that drifted 100 km E. The Aviation Color Code level remained at
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 18-24 August HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within the floor of
Halema'uma'u crater remained mostly stable; glow from the vent was

also visible at night. A plume from the vent mainly drifted SW. At
Pu'u 'O'o crater, incandescence emanated from multiple areas on the N
floor. At the east rift zone, lava that flowed through the TEB lava-
tube system fed occasional surface flows on the pali and on the
coastal plain NW and W of Kalapana Gardens, as well as the Puhi-o-
Kalaikini ocean entry.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that 13-20 August seismic activity from Kliuchevskoi

was above background levels and lava flowed down the SW flank.
Strombolian activity and gas-and-ash emissions were observed during

14-16 August. Cloud cover prevented observations the other days.
Satellite imagery analyses showed a large and intense daily thermal
anomaly from the volcano and ash plumes that drifted more than 325 km
SE. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Meteorological clouds mostly prevented satellite image views of Pagan
during 13-20 August, although steam-and-gas plumes were seen during
clear periods. On 15 August, observers working on a boat reported that
a low-level ash eruption produced a diffuse, dark-colored ash-and-
steam plume. The plume rose to an altitude of 1.5 km (4,900 ft) a.s.l.
and caused minor ashfall on northern Pagan Island and the surrounding
ocean. The Aviation Color Code remained at Yellow and the Volcano

Alert Level remained at Advisory.

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana

Islands, Office of the Governor, United States Geological Survey
Volcano Hazards Program

Pagan Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that on 23 August an ash plume from Popocatépetl
rose 1 km above the crater.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Sakura-jima on 18, 21, and 23 August produced plumes that rose to
altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted W and NW.
On 19 and 24 August pilots observed ash plumes that rose to altitudes

of 1.5-2.7 km (5,000-9,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,

is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SAN CRISTOBAL Nicaragua 12.702°N, 87.004°W; summit elev. 1745 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 20 August an ash plume from San Cristóbal drifted over 35 km
N.

Geologic Summary. The San Cristóbal volcanic complex, consisting of

five principal volcanic edifices, forms the NW end of the Marrabios
Range. The symmetrical 1,745-m-high youngest cone, San Cristóbal
itself (also known as El Viejo), is Nicaragua's highest volcano and is
capped by a 500 x 600 m wide crater. El Chonco, with several flank
lava domes, is located 4 km to the west of San Cristóbal; it and the
eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of
Pleistocene age. Volcán Casita contains an elongated summit crater and
lies immediately E of San Cristóbal; Casita was the site of a
catastrophic landslide and lahar in 1998. The Plio-Pleistocene La
Pelona caldera is located at the eastern end of the San Cristóbal
complex. Historical eruptions from San Cristóbal, consisting of small-
to-moderate explosive activity, have been reported since the 16th
century. Some other 16th-century eruptions attributed to Casita
volcano are uncertain and may pertain to other Marrabios Range
volcanoes.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

San Cristóbal Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

Based on analyses of satellite imagery, the Washington VAAC reported
that on 19 August small ash-and-gas plumes from Sangay drifted about
25 km W and dissipated. Intermittent thermal anomalies were also
detected. On 20 August a pilot reported an emission that was not seen
in satellite imagery.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 13-20 August seismic activity from
Shiveluch was above background levels and gas-and-steam plumes were
seen during 14-16 August. A daily thermal anomaly was seen in
satellite imagery. Based on information from KEMSD, the Tokyo VAAC
reported that during 22-23 August eruptions produced plumes that rose
to altitudes of 6.4-8.5 km (21,000-28,000 ft) a.s.l. The Aviation

Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported most of the rockfalls and pyroclastic flows detected
during 13-20 August originated from the W side of the lava dome and
traveled W down Gages valley. The pyroclastic flows traveled no longer
than 2 km and produced weakly convecting ash clouds. A small lahar
descended the Belham valley to the NW on 19 August. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 21-24 August. Details of possible resulting
plumes were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

RVO reported that white and gray-to-brown plumes rose no more than a
few hundred meters above Ulawun during 12-24 August, and fine ash fell
on the NW and W flanks. Seismicity continued to decrease as compared

Last Post

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Aug 26, 2010, 9:03:09 AM8/26/10

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CORRECTED REPORT

SI / USGS
Weekly Volcanic Activity Report

     18 August-24 August
2010
       1 New+ 15 Ongoing = 16
active

New Activity/Unrest:

| Galeras, Colombia

Ongoing Activity:

Weekly Report Editor Sally Kuhn Sennert -

              This page is updated on Wednesdays, please
              see the GVP Home Page for news of the
              latest significant activity.

The Weekly Volcanic Activity Report is a

cooperative project between the Smithsonian's
Global Volcanism Program and the US

Geological Survey's Volcano Hazards Program.

Updated by 2300 UTC every Wednesday,

notices of volcanic activity posted on these pages

are preliminary and subject to change as events
are studied in more detail.

This is not a comprehensive list of all of

Earths volcanos erupting during the week, but

New Activity/Unrest

Map

Ongoing Activity

VAAC reported that on 8 and 10 August ash-and-steam plumes from mbrym

Map

KVERT reprted that 13-20 August seismic activity from Kliuchevskoi

was above background levels and lava flowed down the SW flank.

Strombolianactivity and gas-and-ash emissions were observed during
14-16 Augus. Cloud cover prevented observations the other days.

Map

volcanos.

Map

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit lev.
3283 m

Map

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit lev.

Last Post

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Sep 1, 2010, 10:32:41 PM9/1/10

to

SI / USGS
Weekly Volcanic Activity Report

        25 August-31 August 2010

4 New+ 15 Ongoing = 17

New Activity/Unrest:

| Ekarma, Kuril Islands (Russia)
| Galeras, Colombia

| Manam, Northeast of New Guinea (SW Pacific)

| Sinabung, Sumatra (Indonesia)

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Cleveland, Chuginadak Island

| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Nevado del Huila, Colombia
| Reventador, Ecuador
| Sakura-jima, Kyushu

| Sangay, Ecuador
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Suwanose-jima, Ryukyu Islands (Japan)

Weekly Report Editor Sally Kuhn Sennert
-

               This page is updated on Wednesdays, please
               see the GVP Home Page for news of the
               latest significant activity.

               The Weekly Volcanic Activity Report is a
               cooperative project between the Smithsonian's
               Global Volcanism Program and the US
               Geological Survey's Volcano Hazards Program.

               Updated by 2300 UTC every Wednesday,
               notices of volcanic activity posted on these pages
               are preliminary and subject to change as events
               are studied in more detail.

This is not a comprehensive list of all of

Earths volcanoseruptingduring theweek, but

      rather a summary of activity at volcanoes that
      meet criteria discussed in detail in the "Criteria
      and Disclaimers" section. Carefully reviewed,
               detailed reports on variousvolcanosare
                 published monthly in the Bulletin of the
                Global Volcanism Network.

               Note: Many news agencies do not archive the
               articles they post on the Internet, and therefore
               the links to some sources may not be active. To
              obtain information about the cited articles that
               are no longer available on the Internet contact
               the source.

New Activity/Unrest

EKARMA Kuril Islands (Russia) 48.958°N, 153.93°E; summit elev. 1170 m

SVERT reported that on 10 August scientists observed a vigorous steam
plume from Ekarma that rose to an altitude of 1.8 km (5,900 ft) a.s.l.
while visiting Sarychev Peak, 110 km SSW. On 24 August scientists
visited Ekarma Island and observed continuous vigorous gas emissions
from a new vent located on the S flank, about 250 m below the summit.
The flanks had been blanketed by a layer of fine ash with a thickness
exceeding 5 cm in the vicinity of the vent. Two recent lahar deposits
were seen on the S flank. Based on their observations, SVERT
speculated that a small eruption may have occurred between early June
and late July 2010. Ekarma does not have a seismic network; satellite
image analysis and infrequent ground observations are the primary tool

for monitoring many of the Kuril Islands volcanoes.

Geologic Summary. The small 5 x 7.5 km island of Ekarma lies 8.5 km
north of Shiashkotan Island along an E-W-trending volcanic chain
extending westward from the central part of the main Kuril Island arc.
Ekarma is composed of two overlapping basaltic-andesite to andesitic
volcanoes, the western of which has been historically active. Lava
flows radiate 3 km in all directions from the summit of the younger
cone to the sea, forming a lobate shoreline. A lava dome that was
emplaced during the first historical eruption, in 1776-79, forms the
peaked, 1170-m-high summit of the island. The only other historical
eruption produced minor explosions in 1980.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Ekarma Information from the Global Volcanism Program

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m

An eruption from Galeras that began at 0400 on 25 August prompted

INGEOMINAS to raise the Alert Level to I (Red; "imminent eruption or
in progress"). Meteorological cloud cover initially prevented visual

observations of the summit. Seismicity associated with the eruption
continued for a period of about 12 hours and gradually declined in the
afternoon. The Alert Level was lowered to II (Orange; "probable
eruption in term of days or weeks"). Scientists aboard an overflight
later that day observed ash-and-gas emissions from multiple areas of
the active cone, and thermal anomalies that were detected on the N
side of the cone. Ash fell to the NW, as far away as 30 km. According
to news articles, about 7,000 were requested by officials to evacuate,
although few left their homes. During 26-31 August at least 12
earthquakes, M 2-4, were located within a 2-km radius from the crater,
at depths not more than 3 km. Gas plumes drifted NW, then S.

Geologic Summary. Galeras, a stratovolcano with a large breached
caldera located immediately W of the city of Pasto, is one of
Colombia's most frequently active volcanoes. The dominantly andesitic
Galeras volcanic complex has been active for more than 1 million
years, and two major caldera collapse eruptions took place during the
late Pleistocene. Longterm extensive hydrothermal alteration has
affected the volcano. This has contributed to large-scale edifice
collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-
shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced
widespread tephra deposits and pyroclastic flows that swept all but
the southern flanks. A central cone slightly lower than the caldera
rim has been the site of numerous small-to-moderate historical
eruptions since the time of the Spanish conquistadors.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS), CNN

Galeras Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

RVO reported that during 13-26 August incandescence from Manam's South
Crater was visible at night. Main Crater emitted diffuse white vapor.
During 27-28 August incandescence emanated from both craters and
brightened every 15-20 minutes. At that time, incandescent lava
fragments ejected tens to hundreds of meters above South Crater were
reported from observers in Bogia, about 23 km SSW. Weak explosions
were heard at 15-20 minute intervals. During 28-29 August diffuse
white-to-blue vapor emissions from Main Crater were occasionally
accompanied by diffuse gray ash plumes. Incandescent lava fragments
continued to be ejected. Based on analysis of satellite imagery, the
Darwin VAAC reported that on 30 August an ash plume rose to an

altitude of 2.4 km (8,000 ft) a.s.l. and drifted 55 km NW.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Manam Information from the Global Volcanism Program

SINABUNG Sumatra (Indonesia) 3.17°N, 98.392°E; summit elev. 2460 m

CVGHM reported that on 28 August Sinabung emitted diffuse white plumes
that rose 20 m and showed no signs of increased activity. On 29 August
rumbling was heard, prompting authorizes to contact and move people
living within a 6-km-radius of the volcano. Later that day, an
explosion produced an ash plume that rose 1.5 km above the crater, and
the Alert Level was raised to 4 (on a scale of 1-4). Media footage of
the eruption at one point showed two closely spaced ash plumes from
vents near the summit, causing domestic flights to be diverted. The
next day a second, more powerful, explosion generated an ash plume
that rose 2 km above the crater. The number of people media sources
reported had evacuated ranged from 20,000-30,000. Ash fell in nearby
areas and a strong sulfur odor was reported. Nighttime video showed
incandescent material descending the flank of the volcano.

Geologic Summary. Gunung Sinabung is a Pleistocene-to-Holocene
stratovolcano with many lava flows on its flanks. The migration of
summit vents along a N-S line gives the summit crater complex an
elongated form. The youngest crater of this conical, 2460-m-high
andesitic-to-dacitic volcano is at the southern end of the four
overlapping summit craters. An unconfirmed eruption was noted in 1881,
and solfataric activity was seen at the summit and upper flanks of
Sinabung in 1912, although no confirmed historical eruptions were
recorded prior to 2010.

Map

Sources: Center of Volcanology and Geological Hazard Mitigation
(CVGHM), Associated Press, Daily Mail

Sinabung Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 26-28 August ash plumes from Batu Tara rose to an altitude of
1.5 km (5,000 ft) a.s.l. and drifted 55-75 km. The plumes drifted W
and NW during 27-28 August.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

AVO reported that on 26 August the Volcano Alert Level for Cleveland
was raised to Advisory, and the Aviation Color Code was raised to
Yellow, due to a persistent thermal anomaly near the summit visible in
satellite imagery on most days during 16-24 August. Cloudy weather
conditions prevented views of the summit during 25-29 August. A
thermal anomaly was again seen in satellite imagery at night during
29-30 August. No current seismic information was available because
Cleveland does not have a real-time seismic network.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 25-29 August ash plumes from Dukono rose to altitudes of 2.1-3
km (7,000-10,000 ft) a.s.l. and drifted 35-110 km W and NE.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 20-27 August seismic activity from Karymsky

was above background levels and suggested that possible ash plumes

rose to an altitude of 3.8 km (12,500 ft) a.s.l. Satellite imagery
showed a thermal anomaly over the volcano during 20 and 23-24 August.

The Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 25-31 August HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within the floor of
Halema'uma'u crater remained mostly stable; glow from the vent was

also visible at night. A plume from the vent drifted SW. At Pu'u 'O'o
crater, incandescence emanated from an active hornito on the N floor.

At the east rift zone, lava that flowed through the TEB lava-tube

system fed minor surface flows on the coastal plain, as well as two
ocean entries at Puhi-o-Kalaikini, SW of Kalapana.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that 20-27 August seismic activity from Kliuchevskoi

was above background levels and lava flowed down the SW flank.

Strombolian activity and gas-and-ash emissions were observed on 20 and
21 August. Cloud cover prevented observations the other days.

Satellite imagery analyses showed a large and intense daily thermal

anomaly from the volcano and ash plumes that drifted more than 200 km
SE on 20 August. Based on analyses of satellite imagery and
information from KEMSD, the Tokyo VAAC reported that an eruption on 28
August produced plumes that rose to altitudes of 7.6-10.4 km
(25,000-34,000 ft) a.s.l. and drifted SE. Satellite imagery showed a
possible eruption on 30 August. The Aviation Color Code level remained
at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

According to the Washington VAAC, the Popayán Volcano Observatory
(INGEOMINAS) received several reports from towns W of Nevado del Huila
that indicated ash emissions on 30 August. Ash was not seen in
satellite imagery, although extensive clouds were present in the area.
A thermal anomaly was detected, however. INGEOMINAS reported that a
pulse of tremor was detected, associated with an ash emission seen in
the web camera at Tafxnú. Ashfall was later confirmed in Toribio, 27
km W.

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),

Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The Washington VAAC reported that on 30 August an ash plume was
observed near Reventador by a pilot. Ash was not seen in satellite
imagery.

Geologic Summary. Reventador is the most frequently active of a chain

of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 26-31 August produced plumes that rose to
altitudes of 1.2-2.1 km (4,000-7,000 ft) a.s.l. Some of the plumes
drifted N and NW.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 30 August an ash plume was
observed near Sangay by a pilot. Ash was not seen in satellite
imagery.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 20-27 August seismic activity from
Shiveluch was above background levels, suggesting that possible ash
plumes rose to an altitude of 8.5 km (27,900 ft) a.s.l. during 20-24
August. Gas-and-ash plumes were observed on 20 and 21 August.
Satellite imagery analysis showed a thermal anomaly on the volcano
during 20-22 and 24 August. The Aviation Color Code level remained at
Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that most of the rockfalls and pyroclastic flows detected
during 20-27 August originated from a vertical face on the SE side of
the lava dome and traveled W down Gages valley and E down the Tar
River valley. The pyroclastic flows traveled no longer than 1.5 km and
produced weakly convecting ash clouds that rose a few hundred meters.

The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima on 25 and 27 August. Details of possible resulting
plumes were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

Sam Wormley

unread,

Sep 1, 2010, 11:05:39 PM9/1/10

to

On 9/1/10 9:32 PM, Last Post wrote:
> Weekly Volcanic Activity

Weekly Reports Archive
http://www.volcano.si.edu/reports/usgs/index.cfm?content=archive

Message has been deleted

Sam Wormley

unread,

Sep 2, 2010, 2:34:32 AM9/2/10

to

On 9/2/10 12:52 AM, Mr.B1ack wrote:

> This is good news. More volcanic activity means
> more micro-sulfate aerosols in the stratosphere
> which means more solar radiation reflected back
> into space. Volcanoes = global cooling.
>
>

:-)

Last Post

unread,

Sep 9, 2010, 3:43:44 PM9/9/10

to

SI / USGS
Weekly Volcanic Activity
Report

          1 September-7 September 2010
         8 New + 11 Ongoing = 19

New Activity/Unrest:

| Ekarma, Kuril Islands (Russia)
| Etna, Sicily (Italy)
| Kliuchevskoi, Central Kamchatka (Russia)

| Manam, Northeast of New Guinea (SW Pacific)

| Planchón-Peteroa, Central Chile-Argentina border
| Seulawah Agam, Sumatra (Indonesia)
| Sinabung, Sumatra (Indonesia)
| Villarrica, Central Chile

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Bezymianny, Central Kamchatka (Russia)

| Cleveland, Chuginadak Island
| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Pacaya, Guatemala
| Sakura-jima, Kyushu
| Sangay, Ecuador

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

New Activity/Unrest

MA Kuril Islands (Russia) 48.958°N, 153.93°E; summit elev. 1170 m

On 6 September, SVERT reported that strong steam-and-gas activity from
Ekarma continued. Ekarma does not have a seismic network; satellite

image analysis and infrequent ground observations are the primary tool
for monitoring many of the Kuril Islands volcanoes.

Geologic Summary. The small 5 x 7.5 km island of Ekarma lies 8.5 km
north of Shiashkotan Island along an E-W-trending volcanic chain
extending westward from the central part of the main Kuril Island arc.
Ekarma is composed of two overlapping basaltic-andesite to andesitic
volcanoes, the western of which has been historically active. Lava
flows radiate 3 km in all directions from the summit of the younger
cone to the sea, forming a lobate shoreline. A lava dome that was
emplaced during the first historical eruption, in 1776-79, forms the
peaked, 1170-m-high summit of the island. The only other historical
eruption produced minor explosions in 1980.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Ekarma Information from the Global Volcanism Program

ETNA Sicily (Italy) 37.734°N, 15.004°E; summit elev. 3330 m

INGV-CT reported that on 25 August a powerful explosion from Etna's
Bocca Nuova crater initiated a series of ash emissions, which
continued at decreasing strength for about 20 minutes. A thermal
camera located at La Montagnola, 3 km S of the summit craters, showed
ejected hot material and a cauliflower-shaped, dark gray ash plume
that rose about 1 km and drifted E. Ashfall was reported in areas SE
from Etna to Catania (27 km S). An inspection the next morning
revealed that the W wall of the BN-1 crater of Bocca Nuova had
collapsed. During 25-29 August a total of seven explosions were
recorded.

Geologic Summary. Mount Etna, towering above Catania, Sicily's second
largest city, has one of the world's longest documented records of
historical volcanism, dating back to 1500 BC. Historical lava flows
cover much of the surface of this massive basaltic stratovolcano, the
highest and most voluminous in Italy. Two styles of eruptive activity
typically occur at Etna. Persistent explosive eruptions, sometimes
with minor lava emissions, take place from one or more of the three
prominent summit craters, the Central Crater, NE Crater, and SE
Crater. Flank eruptions, typically with higher effusion rates, occur
less frequently and originate from fissures that open progressively
downward from near the summit. A period of more intense intermittent
explosive eruptions from Etna's summit craters began in 1995. The
active volcano is monitored by the Instituto Nazionale di Geofisica e
Volcanologia (INGV) in Catania.

Map

Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di
Catania (INGV-CT)

Etna Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that 27 August-3 September seismic activity from

Kliuchevskoi was above background levels and lava flowed down the SW

flank. Satellite imagery analyses showed a large and intense daily
thermal anomaly over the volcano. On 27 August, activity increased;
ash plumes rose to an altitude of 6 km (19,700 ft) a.s.l. and drifted
120 km SE. Strombolian activity was observed during 27-30 August.
Phreatic explosions occurred on the SW flank on 29 and 30 August. Ash
plumes rose to an altitude of 6.5 km (21,300 ft) a.s.l. on 30 August
and drifted 278 km SE.

Based on analyses of satellite imagery and information from the
Yelizovo Airport (UHPP), the Tokyo VAAC reported a possible eruption
on 3 September. Subsequent images showed continuing emissions. Later
that day a notice stated that ash had dissipated. Another possible
eruption that day produced a plume that rose to an altitude of 5.5 km
(18,000 ft) a.s.l. and drifted E. During 4-7 September eruptions
reported by KVERT and seen in satellite imagery produced ash plumes
that rose to altitudes of 5.2-7 km (17,000-23,000 ft) a.s.l. and
drifted NW, E, and SE. The Aviation Color Code level remained at
Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

RVO reported that ash plumes and diffuse blue vapor plumes rose 150 m
from Manam's Main Crater on 30 August. That same day gray emissions
rose from South Crater at 5-10 minute intervals. During 30 August-2
September incandescence was observed when the craters could be seen.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Rabaul Volcano Observatory (RVO)

Manam Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

SERNAGEOMIN reported that on 6 September an explosive eruption from
Planchón-Peteroa produced an ash plume that rose 1.2 km above the
complex and drifted mainly E to a distance of 30 km, with some parts
of the plume going N and S. That same day SERNAGEOMIN received
pictures from Romeral (approximately 61 km NW) that showed ash-and-gas
plumes rising 200 m.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Planchón-Peteroa Information from the Global Volcanism Program

SEULAWAH AGAM Sumatra (Indonesia) 5.448°N, 95.658°E; summit elev. 1810
m

CVGHM reported that although seismicity from Seulawah Agam fluctuated
during April to August 2010, the data reflected increased activity
overall. On 1 September, CVGHM raised the Alert Level to 2 (on a scale
of 1-4) and restricted visitors from approaching the crater within a 3-
km radius.

Geologic Summary. Seulawah Agam at the NW tip of Sumatra is an
extensively forested volcano of Pleistocene-Holocene age constructed
within the large Pleistocene Lam Teuba caldera. A smaller 8 x 6 km
caldera lies within Lam Teuba caldera. The summit contains a forested,
400-m-wide crater. The active van Heutsz crater, located at 650 m on
the NNE flank of Suelawah Agam, is one of several areas containing
active fumarole fields. Sapper (1927) and the Catalog of Active
Volcanoes of the World (CAVW) reported an explosive eruption in the
early 16th century, and the CAVW also listed an eruption from the van
Heutsz crater in 1839. Rock et al. (1982) found no evidence for
historical eruptions. However the Volcanological Survey of Indonesia
noted that although no historical eruptions have occurred from the
main cone, the reported NNE-flank explosive activity may have been
hydrothermal and not have involved new magmatic activity.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Seulawah Agam Information from the Global Volcanism Program

SINABUNG Sumatra (Indonesia) 3.17°N, 98.392°E; summit elev. 2460 m

According to news articles, about 6,000 of the approximately 30,000
people that evacuated the area around Sinabung after the eruption
during 29-30 August returned home within a few days because activity
had decreased. The Darwin VAAC reported a large explosion on 3
September, based on information from CVGHM. News reports stated that
the explosion vibrated homes and trees on the flanks, and generated a
3-km-high ash plume. CVGHM reported that another large explosion on 7
September produced an ash plume that rose 5 km above the crater and
drifted SE. Strong vibrations caused by the explosion were detected as
far away as 8 km SE.

Geologic Summary. Gunung Sinabung is a Pleistocene-to-Holocene
stratovolcano with many lava flows on its flanks. The migration of
summit vents along a N-S line gives the summit crater complex an
elongated form. The youngest crater of this conical, 2460-m-high
andesitic-to-dacitic volcano is at the southern end of the four
overlapping summit craters. An unconfirmed eruption was noted in 1881,
and solfataric activity was seen at the summit and upper flanks of
Sinabung in 1912, although no confirmed historical eruptions were
recorded prior to 2010.

Map

Sources: Center of Volcanology and Geological Hazard Mitigation

(CVGHM), Associated Press, Jakarta Post, CNN

Sinabung Information from the Global Volcanism Program

VILLARRICA Central Chile 39.42°S, 71.93°W; summit elev. 2847 m

Based on analyses of satellite imagery, the Buenos Aires VAAC reported

that on 4 September a diffuse ash plume from Villarrica, possibly
containing steam and gas, drifted NE.

Geologic Summary. Villarrica, one of Chile's most active volcanoes,
rises above the lake and town of the same name. It is the westernmost
of three large stratovolcanoes that trend perpendicular to the Andean
chain. A 6-km wide caldera formed during the late Pleistocene, more
than 0.9 million years ago. A 2-km-wide postglacial caldera is located
at the base of the presently active, dominantly basaltic-to-andesitic
cone at the NW margin of the Pleistocene caldera. About 25 scoria
cones dot Villarrica's flanks. Plinian eruptions and pyroclastic flows
have been produced during the Holocene from this dominantly basaltic
volcano, but historical eruptions have consisted largely of mild-to-
moderate explosive activity with occasional lava effusion. Lahars from
the glacier-covered volcano have damaged towns on its flanks.

Map

Source: Buenos Aires Ash Advisory Center (VAAC)

Villarrica Information from the Global Volcanism Program

Ongoing Activity:

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 1-7 September ash plumes from Batu Tara rose to altitudes of
1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted 45-65 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit
elev. 2882 m

KVERT reported that a thermal anomaly over Bezymianny was observed in
satellite imagery on 29 August and 1 September. Gas-and-steam activity
was also noted on 1 September. Cloud cover prevented observations of
the volcano on the other days during 27 August-3 September. The
Aviation Color Code level remained at Yellow.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny
volcano had been considered extinct. Three periods of intensified
activity have occurred during the past 3,000 years. The latest period,
which was preceded by a 1,000-year quiescence, began with the dramatic
1955-56 eruption. That eruption, similar to the 1980 event at Mount
St. Helens, produced a large horseshoe-shaped crater that was formed
by collapse of the summit and an associated lateral blast. Subsequent
episodic but ongoing lava-dome growth, accompanied by intermittent
explosive activity and pyroclastic flows, has largely filled the 1956
crater.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bezymianny Information from the Global Volcanism Program

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

AVO reported that during 31 August-1 September thermal anomalies from
Cleveland were detected in satellite imagery. The Volcano Alert Level
remained at Advisory and the Aviation Color Code remained at Yellow.

No current seismic information was available because Cleveland does
not have a real-time seismic network.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 1-2 and 6-7 September ash plumes from Dukono rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted almost 95 km W and
NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 27 August-3 September seismic activity from

Karymsky was above background levels and suggested that possible ash

plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. Satellite
imagery showed a thermal anomaly over the volcano during the week and
an ash plume that drifted 23 km on 28 August. The Aviation Color Code
level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 1-7 September HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within the floor of
Halema'uma'u crater remained mostly stable; glow from the vent was

also visible at night. A plume from the vent drifted SW and deposited
ash nearby. At Pu'u 'O'o crater, incandescence emanated from an active
hornito on the N floor. On 4 September lava started to flow along the
S margin of the crater floor and was active the next day. At the east

rift zone, lava that flowed through the TEB lava-tube system fed minor

surface flows on the coastal plain, as well as the Puhi-o-Kalaikini
ocean entry.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that during 1-2 September steam plumes rose from
Pacaya's MacKenney cone and drifted NE and W.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 1-5 September produced plumes that rose to
altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. Some of the plumes
drifted N, NW, and W. During 2-4 September pilots reported that ash
plumes rose to altitudes of 2.1-3.4 km (7,000-11,000 ft) a.s.l. An
explosion also occurred on 7 September.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 5 September an ash plume from
Sangay that rose to an altitude of 5.5 km (18,000 ft) a.s.l. was
observed by a pilot. Ash was not seen in satellite imagery.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 1 September fumarolic plumes from Santa
María's Santiaguito lava dome complex rose less than 100 m above the
crater and drifted SE. Ashfall was reported in an area to the SW. On 2
September block avalanches descended the W flank. On 2 and 6 September
explosions produced ash plumes that rose 500-1,000 m and drifted W and
SW.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is

one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 27 August-3 September seismic activity from

Shiveluch was above background levels, suggesting that possible ash

plumes rose to an altitude of 6.5 km (21,300 ft) a.s.l. Satellite
imagery analysis showed a thermal anomaly on the volcano. Gas-and-ash
plumes were observed during 27-30 August. Based on information from
KEMSD and satellite imagery analyses, the Tokyo VAAC reported that
during 2-3 September eruptions produced plumes that rose to an
altitude of 6.7 km (22,000 ft) a.s.l. The Aviation Color Code level
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

Sam Wormley

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Sep 9, 2010, 7:12:33 PM9/9/10

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On 9/9/10 2:43 PM, Last Post wrote:
> Weekly Volcanic Activity
> Report
>
>
>
> 1 September-7 September 2010
> 8 New + 11 Ongoing = 19

Weekly Reports Archive
http://www.volcano.si.edu/reports/usgs/index.cfm?content=archive

Last Post

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Sep 15, 2010, 6:03:59 PM9/15/10

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SI / USGS
Weekly Volcanic Activity Report

           8 September-14 September 2010
          7 New + 11 Ongoing = 18

New Activity/Unrest:

| Cleveland, Chuginadak Island
| Ekarma, Kuril Islands (Russia)

| Kliuchevskoi, Central Kamchatka (Russia)
| Nevado del Huila, Colombia

| Planchón-Peteroa, Central Chile-Argentina border
| Santa María, Guatemala
| Sinabung, Sumatra (Indonesia)

Ongoing Activity:

| Arenal, Costa Rica

| Batu Tara, Komba Island (Indonesia)

| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

Weekly Report Editor Sally Kuhn Sennert

http://www.volcano.si.edu/reports/
usgs

New Activity/Unrest

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

AVO reported that during 7-8 September clear-weather satellite views
of Cleveland showed no thermal anomalies or recent deposits on the
flanks. The Volcano Alert Level and the Aviation Color Code were
lowered to Unassigned. On 11 September, a thermal anomaly was observed
in satellite imagery. The next day a possible ash plume seen in
satellite imagery rose to the estimated altitude of 7.6 km (25,000 ft)
a.s.l. and drifted E. The Volcano Alert Level and the Aviation Color
Code were again raised to Advisory and Yellow, respectively. A thermal
anomaly was again visible during 13-14 September.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

EKARMA Kuril Islands (Russia) 48.958°N, 153.93°E; summit elev. 1170 m

On 13 September, SVERT reported that strong steam-and-gas activity

from Ekarma continued. Ekarma does not have a seismic network;
satellite image analysis and infrequent ground observations are the
primary tool for monitoring many of the Kuril Islands volcanoes.

Geologic Summary. The small 5 x 7.5 km island of Ekarma lies 8.5 km
north of Shiashkotan Island along an E-W-trending volcanic chain
extending westward from the central part of the main Kuril Island arc.
Ekarma is composed of two overlapping basaltic-andesite to andesitic
volcanoes, the western of which has been historically active. Lava
flows radiate 3 km in all directions from the summit of the younger
cone to the sea, forming a lobate shoreline. A lava dome that was
emplaced during the first historical eruption, in 1776-79, forms the
peaked, 1170-m-high summit of the island. The only other historical
eruption produced minor explosions in 1980.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Ekarma Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 3-10 September seismic activity from

Kliuchevskoi was above background levels and lava flowed down the SW

and NW flanks. Satellite imagery analyses showed a large and intense
daily thermal anomaly over the volcano. During 2-4 September ash
plumes seen in satellite imagery drifted 150 km S and SW at an
altitude of 6.5 km (21,300 ft) a.s.l. Phreatic bursts on the SW flank
were observed on 5 September and Strombolian activity was seen during
5-7 September. Seismic data suggested that during 5-6 September ash

plumes rose to an altitude of 6 km (19,700 ft) a.s.l.

Based on analyses of satellite imagery, the Tokyo VAAC reported that a
possible eruption on 12 September produced a plume that rose to an
altitude of 7.6 km (25,000 ft) a.s.l. and drifted SE. On 13 September
an ash plume rose to an altitude of 9.8 km (32,000 ft) a.s.l. and
drifted NE according to information sent from the Yelizovo Airport
(UHPP). Ash was seen in subsequent satellite images during 13-14
September. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

The Popayán Volcano Observatory (INGEOMINAS) reported increased
activity from Nevado del Huila on 8 and 9 September. Pulses of tremor
were associated with periodic emissions of gas, ash, and incandescent
material observed with the Tafxnú and Maravillas web cameras. During
8-14 September plumes of steam and occasionally ash rose as high as 2
km above the summit. The Alert Level was raised to II (Orange;

"probable eruption in term of days or weeks").

Geologic Summary. Nevado del Huila, the highest active volcano in

Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Huila Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

SERNAGEOMIN reported that an overflight of Planchón-Peteroa on 7
September revealed that the explosions the day before were possibly
phreato-magmatic in origin and similar to the explosions in 1991.
Pulses of gas and ash had occurred every 40-60 seconds during the
eruption. Plumes rose 200 m above the crater and ash mostly fell
within 10 km to the E. During 10-13 September, plumes rising from the
vent had progressively less ash and higher concentrations of water
vapor. On 13 September, SERNAGEOMIN reported that petrographic and
mineralogical studies of the ash indicated no juvenile components. The
Alert Level remained at 4, Yellow.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Planchón-Peteroa Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that an eruption from Santa María's Santiaguito
lava dome complex on 11 September generated two pyroclastic flows that
traveled 3 km SW and deposited material in the Nimá II drainage. Ash
plumes rose 1 km above the crater and drifted E and SE. On 13
September white plumes rose 100 m and drifted S.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SINABUNG Sumatra (Indonesia) 3.17°N, 98.392°E; summit elev. 2460 m

CVGHM reported that during 8-11 September Sinabung emitted white-to-
gray plumes that rose 30-100 m above the crater and generally drifted
E. Deformation measurements during 8-14 September showed a slow rate
of inflation. Based on analyses of satellite imagery and the CVGHM web
camera, the Darwin VAAC reported that on 12 and 14 September ash
plumes rose to altitudes of 4.3-4.6 km (14,000-15,000 ft) a.s.l. The
Alert Level remained at 4 (on a scale of 1-4).

Geologic Summary. Gunung Sinabung is a Pleistocene-to-Holocene
stratovolcano with many lava flows on its flanks. The migration of
summit vents along a N-S line gives the summit crater complex an
elongated form. The youngest crater of this conical, 2460-m-high
andesitic-to-dacitic volcano is at the southern end of the four
overlapping summit craters. An unconfirmed eruption was noted in 1881,
and solfataric activity was seen at the summit and upper flanks of
Sinabung in 1912, although no confirmed historical eruptions were
recorded prior to 2010.

Map

Sources: Center of Volcanology and Geological Hazard Mitigation

(CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Sinabung Information from the Global Volcanism Program

ONGOING ACTIVITY

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during August activity originating from

Arenal's Crater C consisted of gas emissions, sporadic Strombolian
eruptions, and occasional avalanches. Some of the Strombolian

eruptions caused glass to vibrate in buildings located 6.5 km NE.
Block avalanches descended the N and NE flanks. Acid rain and small

amounts of ejected pyroclastic material affected the NE, E, and SE

flanks. Crater D produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 8 September an ash plume from Batu Tara rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 55 km NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 8-11 and 14 September ash plumes from Dukono rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted 35-95 km SW, W, and
NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 3-10 September seismic activity from

Karymsky was above background levels and suggested that possible ash

plumes rose to an altitude of 3.2 km (10,500 ft) a.s.l. Satellite
imagery showed a thermal anomaly over the volcano during the week. The

Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 8-14 September HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within the floor of
Halema'uma'u crater remained mostly stable; glow from the vent was
also visible at night. A plume from the vent drifted SW and deposited

ash, and occasionally Pele's hair and spatter, nearby. At Pu'u 'O'o
crater, incandescence emanated from a lava flow on the SW floor on
most nights. During an overflight on 9 September, geologists saw that
the lava flow had ponded on the W side of the crater floor. At the

east rift zone, lava that flowed through the TEB lava-tube system

mainly fed the Puhi-o-Kalaikini ocean entry.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The Washington VAAC reported that on 9 September an ash plume from
Reventador at an altitude of 5.5 km (18,000 ft) a.s.l. was observed by
a pilot.

Geologic Summary. Reventador is the most frequently active of a chain

of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima on 8 and 10 September produced plumes that rose to
altitudes of 1.5-1.8 km (6,000-8,000 ft) a.s.l. Some of the plumes
drifted E and NE. On 9 September a pilot reported that an ash plume

rose to an altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,

is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 10 September a small plume and a
thermal anomaly from Sangay were seen in satellite imagery. Based on
information from Tegucigalpa MWO, pilot observations, and analyses of
satellite imagery, the VAAC reported that on 13 September small plumes
of gas with possible ash drifted SW. A thermal anomaly had also been
detected for the previous few hours.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 3-10 September seismic activity from
Shiveluch was above background levels and suggested that possible ash
plumes rose to an altitude of 6.5 km (21,300 ft) a.s.l. during 3-4
September. Gas-and-ash plumes were observed on 6 and 7 September;
clouds prevented observations on the other days. Satellite imagery
analysis showed a thermal anomaly on the volcano during the week. The

Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that several small-to-moderate sized pyroclastic flows
from Soufrière Hills during 3-10 September removed parts of the cold
dome carapace, resulting in the thermal camera displaying several
hotter regions on the lava dome. The largest pyroclastic flow traveled
2.5 km down the Gages valley to the W on 9 September. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.

799 m

Based on information from JMA, the Tokyo VAAC reported an explosion
from Suwanose-jima on 11 September. Details of possible resulting
plumes were not reported.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

leona...@gmail.com

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Sep 23, 2010, 2:18:09 AM9/23/10

to

SI / USGS
Weekly Volcanic Activity Report

         15 September-21 September 2010
           6 New + 8 Ongoing = 14

New Activity/Unrest:

| Cleveland, Chuginadak Island
| Kliuchevskoi, Central Kamchatka (Russia)
| Machín, Colombia

| Manam, Northeast of New Guinea (SW Pacific)
| Planchón-Peteroa, Central Chile-Argentina border

| Sinabung, Sumatra (Indonesia)

Ongoing Activity:

| Batu Tara, Komba Island (Indonesia)

| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Sakura-jima, Kyushu
| Sangay, Ecuador
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)

New Activity/Unrest

AVO reported that on 15 September a thermal anomaly from Cleveland was
detected in satellite imagery. Cloud cover prevented views of the
volcano during 16-21 September. The Volcano Alert Level remained at

Advisory and the Aviation Color Code remained at Yellow. No current
seismic information was available because Cleveland does not have a
real-time seismic network.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is

situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 10-17 September seismic activity from

Kliuchevskoi was above background levels and lava flowed down the SW

flank. Satellite imagery analyses showed a large and intense daily
thermal anomaly over the volcano. During 9-15 September ash plumes
rose to altitudes of 6-7 km (19,700-23,000 ft) a.s.l. and drifted 575
km S and SE based on analyses of satellite imagery and visual
observations. Strombolian activity was seen on 11 September. Based on
analyses of satellite imagery and information from KEMSD, the Tokyo
VAAC reported that possible eruptions on 21 and 22 September produced
ash plumes that rose to altitudes of 5.2-6.1 km (17,000-20,000 ft)
a.s.l. and drifted E. The Aviation Color Code level remained at
Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

MACHIN Colombia 4.48°N, 75.392°W; summit elev. 2650+ m

According to INGEOMINAS, Observatory Vulcanológico and Sismológico de
Manizales reported increased seismicity from Cerro Machín on 17
September. About 140 volcano-tectonic earthquakes as large as M 1.85
were located S and SW of the main lava dome at depths of 2-4 km. The
Alert level remained at III (Yellow; "changes in the behavior of
volcanic activity").

Geologic Summary. The small Cerro Machín stratovolcano lies at the
southern end of the Ruiz-Tolima massif about 20 km WNW of the city of
Ibagué. A 3-km-wide caldera is breached to the S and contains three
forested lava domes. Voluminous pyroclastic flows traveled up to 40 km
from the volcano during eruptions in the mid-to-late Holocene perhaps
associated with formation of the caldera. Late-Holocene eruptions
produced block-and-ash flows that traveled through the breach in the
caldera rim to the W and S. The latest known eruption of Volcán Cerro
Machín took place about 800 years ago.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Machín Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

RVO reported that during 5-7 September ash plumes were seen rising
from Manam's South Crater when the weather did not prevent
observations. Light ashfall was reported on the NW part of the island.
Variable amounts of white vapor that was sometimes tinted blue rose
from Main Crater.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Rabaul Volcano Observatory (RVO)

Manam Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

According to NASA's Earth Observatory, a satellite image of Planchón-
Peteroa shows an ash plume drifting 22 km SE on 18 September and
ashfall on the snow beneath the plume. The Buenos Aires VAAC reported
that according to a SIGMET issued on 21 September an ash plume rose to
an altitude of 6.1 km (20,000 ft) a.s.l and drifted SE. Ash was not
identified in satellite imagery. The Alert Level remained at 4,
Yellow.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Sources: Earth Observatory, Buenos Aires Volcanic Ash Advisory Center
(VAAC)

Planchón-Peteroa Information from the Global Volcanism Program

SINABUNG Sumatra (Indonesia) 3.17°N, 98.392°E; summit elev. 2460 m

Based on information from CVGHM and views through a web camera, the
Darwin VAAC reported that during 15-18 September ash plumes from
Sinabung rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted
W. CVGHM reported a slow rate of inflation during 15-18 September
followed by deflation during 19-21 September. Fog mostly prevented
visual observations. On 20 September diffuse white plumes rose 30 m
above the crater and drifted NE. The Alert Level remained at 4 (on a
scale of 1-4).

Geologic Summary. Gunung Sinabung is a Pleistocene-to-Holocene
stratovolcano with many lava flows on its flanks. The migration of
summit vents along a N-S line gives the summit crater complex an
elongated form. The youngest crater of this conical, 2460-m-high
andesitic-to-dacitic volcano is at the southern end of the four
overlapping summit craters. An unconfirmed eruption was noted in 1881,
and solfataric activity was seen at the summit and upper flanks of
Sinabung in 1912, although no confirmed historical eruptions were
recorded prior to 2010.

Map

Sources: Center of Volcanology and Geological Hazard Mitigation
(CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Sinabung Information from the Global Volcanism Program

Ongoing Activity

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 18-20 September ash plumes from Batu Tara rose to an altitude
of 1.5 km (5,000 ft) a.s.l. and drifted 35-95 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

15-18 and 20 September ash plumes from Dukono rose to an altitude of
2.4 km (8,000 ft) a.s.l. The plumes drifted 90-260 km NW and W during
17-18 and 20-21 September.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 10-17 September seismic activity from
Karymsky was above background levels, and suggested that possible ash
plumes rose to an altitude of 3.2 km (10,500 ft) a.s.l. on 15
September. Satellite imagery showed a thermal anomaly over the volcano
during 10-11 and 14 September. The Aviation Color Code level remained
at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's

eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 15-21 September HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within the

Halema'uma'u crater remained mostly stable at about 160 m below the
crater floor; periodically the lava rose 20-40 m above the stable
surface level. Glow from the vent was also visible at night. A plume
from the vent drifted SW and deposited ash nearby. At Pu'u 'O'o
crater, incandescence emanated from a lava flow on the SW floor during
16-19 September. At the east rift zone, lava that flowed through the
TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry. Weak
thermal anomalies detected in satellite imagery during 17-19 September
suggested little to no lava flow activity on the pali or the coastal
plain.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported an eruption
from Sakura-jima on 15 September. That same day a pilot observed an
ash plume at an altitude of 3 km (10,000 ft) a.s.l. On 16 September a
pilot reported that an ash plume rose to an altitude of 1.8 km (6,000
ft) and drifted SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 21 September an ash plume from
Sangay rose to an altitude of 7.6 km (25,000 ft) a.s.l. and was
observed by a pilot. Ash was not seen in satellite imagery, although
weather clouds were in the area.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 10-17 September seismic activity from

Shiveluch was above background levels and suggested that possible ash

plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. Satellite

imagery analysis showed a thermal anomaly on the volcano. Gas-and-ash

plumes were observed during 12-15 September; clouds prevented
observations on the other days. The Aviation Color Code level remained
at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 19-21 September. Details of possible resulting
plumes were not reported.

Map

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Sep 29, 2010, 8:35:33 PM9/29/10

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SI / USGS
Weekly Volcanic Activity Report

          22 September-28 September 2010
            5 New + 9 Ongoing = 14

New Activity/Unrest:

Ongoing Activity:

| Cleveland, Chuginadak Island

| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Reventador, Ecuador
| Sakura-jima, Kyushu

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)

Weekly Report Editor Sally Kuhn Sennert

                   This page is updated on Wednesdays, please
                    see the GVP Home Page for news of the
                   latest significant activity.

                   The Weekly Volcanic Activity Report is a
                   cooperative project between the Smithsonian's
                   Global Volcanism Program and the US
                   Geological Survey's Volcano Hazards Program.

                   Updated by 2300 UTC every Wednesday,
                   notices of volcanic activity posted on these
pages are preliminary and subject to change
                   as events are studied in more detail.

                   This is not a comprehensive list of all of
          Earths volcanoseruptingduring theweek, but
          rather a summary of activity at volcanoes that
          meet criteria discussed in detail in the
"Criteria and Disclaimers" section. Carefully
                   reviewed, detailed reports on various

volcanosare published monthly in the

Bulletin of the Global Volcanism Network.

                   Note: Many news agencies do not archive the
                   articles they post on the Internet, and
therefore the links to some sources may not
                   be active. Too btain information about the
                  cited articles that are no longer available
on
                   the Internet contact the source.

New Activity/Unrest

KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m

CVGHM reported that during 1-7 September lava seen from the
observation post (5 km SSW) traveled 75 m down Karangetang's flanks.
Avalanches traveled as far as 1.5 km down the Batang (S), Batu Awang
(E), and Nanitu drainages. Incandescent material was ejected 350 m
above the crater. During 8-21 September lava traveled 500 m down the
flanks. Avalanches originating from the end of the lava flow traveled
as far as 2 km down the Batang, Kahetang (E), and Nanitu drainages.
During 18-20 September material was ejected 300-500 m above the
crater. Ashfall was reported in areas to the NW. On 21 and 22
September incandescent material traveled down multiple drainages.
Strombolian activity was observed on 22 September; material ejected 50
m high fell back down around the crater. That same day the Alert level
was raised to 3 (on a scale of 1-4).

Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi, and contains five
summit craters strung along a N-S line. One of Indonesia's most active
volcanoes, Karangetang has had more than 40 recorded eruptions since
1675. Twentieth-century eruptions have included frequent explosions,
sometimes accompanied by pyroclastic flows and lahars.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Karangetang [Api Siau] Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 17-24 September seismic activity from
Kliuchevskoi was above background levels and lava from the summit
crater flowed down the SW flank. Satellite imagery analyses showed a
large and intense daily thermal anomaly over the volcano. Strombolian
activity was observed during 17 and 20-21 September, and ash plumes
were seen rising to altitudes of 6.5-7 km (21,300-23,000 ft) a.s.l. on
20 and 21 September. Satellite imagery showed ash plumes drifting
about 60 km W on 19 September and about 240 km E on 20 and 21

September. The Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active

volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

MERAPI Central Java (Indonesia) 7.542°S, 110.442°E; summit elev. 2968
m

CVGHM reported that a pattern of increasing seismicity from Merapi
began in to emerge in early September. Observers at Babadan (7 km W)
and Kaliurang (8 km S) heard an avalanche on 12 September. On 13
September white plumes rose 800 m above the crater. Inflation,
detected since March, increased from background levels of 0.1 to 0.3
mm per day to a rate of 11 mm per day on 16 September. On 19 September
earthquakes continued to be numerous, and the next day CVGHM raised
the Alert Level to 2 (on a scale of 1-4).

Geologic Summary. Merapi, one of Indonesia's most active volcanoes,
lies in one of the world's most densely populated areas and dominates
the landscape immediately N of the major city of Yogyakarta. The steep-
sided modern Merapi edifice, its upper part unvegetated due to
frequent eruptive activity, was constructed to the SW of an arcuate
scarp cutting the eroded older Batulawang volcano. Pyroclastic flows
and lahars accompanying growth and collapse of the steep-sided active
summit lava dome have devastated cultivated and inhabited lands on the
volcano's western-to-southern flanks and caused many fatalities during
historical time. The volcano is the object of extensive monitoring
efforts by the Merapi Volcano Observatory (MVO).

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Merapi Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

Starting on 14 August and continuing through 10 September, OVPDLF
recorded a slow but steady increase in the number and magnitude of
earthquakes from Piton de la Fournaise. Inflation of the summit area
began in late August. A report on 13 September noted localized
deformation W of Dolomieu crater and a small number of landslides in
the crater. On 20 September a significant increase in earthquakes was
recorded, although the average magnitude was low. The earthquakes were
located at the base of Piton de la Fournaise, W and S of Dolomieu
crater. A seismic crisis on 24 September was characterized by several
tens of earthquakes located beneath Dolomieu crater, and occurred in
conjunction with 3 cm of inflation. The Alert level was raised to 1
("Probable or Imminent Eruption").

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

Based on analyses of satellite imagery, the Buenos Aires VAAC reported
that on 26 September an ash plume from Planchón-Peteroa rose to an
altitude of 4.3 km (14,000 ft) a.s.l. and drifted SSE.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Planchón-Peteroa Information from the Global Volcanism Program

SINABUNG Sumatra (Indonesia) 3.17°N, 98.392°E; summit elev. 2460 m

CVGHM reported that on 22 September a white plume from Sinabung rose
as high as 100 m above the crater. On 23 September the Alert Level was
lowered to 3 (on a scale of 1-4).

Geologic Summary. Gunung Sinabung is a Pleistocene-to-Holocene
stratovolcano with many lava flows on its flanks. The migration of
summit vents along a N-S line gives the summit crater complex an
elongated form. The youngest crater of this conical, 2460-m-high
andesitic-to-dacitic volcano is at the southern end of the four
overlapping summit craters. An unconfirmed eruption was noted in 1881,
and solfataric activity was seen at the summit and upper flanks of
Sinabung in 1912, although no confirmed historical eruptions were
recorded prior to 2010.

Map

Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)

Sinabung Information from the Global Volcanism Program

Ongoing Activity

CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

AVO reported that during 25-26 September a weak thermal anomaly from

Cleveland was detected in satellite imagery. Cloud cover prevented

views of the volcano during 22-24 and 27-28 September. The Volcano

Alert Level remained at Advisory and the Aviation Color Code remained
at Yellow. No current seismic information was available because
Cleveland does not have a real-time seismic network.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is
situated at the western end of the uninhabited dumbbell-shaped
Chuginadak Island in the east-central Aleutians. The 1,730-m-high
stratovolcano is the highest of the Islands of Four Mountains group
and is one of the most active in the Aleutians. Numerous large lava
flows descend its flanks. It is possible that some 18th to 19th
century eruptions attributed to Carlisle (a volcano located across the
Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In
1944 Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been characterized
by short-lived explosive ash emissions, at times accompanied by lava
fountaining and lava flows down the flanks.

Map

Source: Alaska Volcano Observatory (AVO)

Cleveland Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 21-25 September ash plumes from Dukono rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 35-95 km W.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that seismic activity from Karymsky was above
background levels during 16-20 September and suggested possible ash
explosions. Seismicity was at background levels on 21 and 22
September. Cloud cover prevented satellite image views. The Aviation

Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 22-28 September HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,

the level of the lava-pool surface in the deep pit within Halema'uma'u
crater remained mostly stable around 160 m below the crater floor;
periodically the lava rose 15-35 m above that level. Glow from the

vent was also visible at night. A plume from the vent drifted SW and

deposited ash nearby. At the east rift zone, lava that flowed through

the TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry.

Weak thermal anomalies detected in satellite imagery suggested little
to no lava flow activity on the pali or the coastal plain. On 26
September lava broke out of the lava-tube system W of the end of
Highway 130 and produced a flow E toward Kalapana Gardens. The next
day lava, flowing at a slower rate, filled in low areas S of the
Hawaii County lava viewing area.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The IG reported that on 28 September three seismic events from
Reventador were recorded. Cloud cover prevented observations during
the first event. During the second period of increased seismicity,
observers noted that a steam plume with a small amount of ash rose
400-500 m above the crater and drifted N. The third episode was
accompanied by a steam-and-ash plume that rose 2 km above the crater
and drifted NW. Ash fell on Reventador.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Reventador Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on a pilot observation, the Tokyo VAAC reported that on 22
September an ash plume rose to an altitude of 1.8 km (6,000 ft) a.s.l.
and drifted SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 17-24 September seismic activity from

Shiveluch was above background levels and suggested that possible ash

plumes rose to an altitude of 3.5 km (11,500 ft) a.s.l. Satellite

imagery analysis showed a thermal anomaly on the volcano. Gas-and-ash

plumes were observed on 21 September, and satellite imagery showed ash
plumes drifting 16 km SE the same day. The Aviation Color Code level
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 17-24 September activity from the Soufrière
Hills lava dome was at a low level. Heavy rains caused lahars during
19-20 September in the Belham valley to the NW. One pyroclastic flow
traveled 1.5 km E down the Tar River valley on 21 September. The

Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 22, 25, and 27-28 September. A pilot observed an
ash plume on 22 September that rose to an altitude of 2.1 km (7,000
ft) a.s.l. and drifted SE. JMA noted that plumes on 25 September rose
to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted E.

Map

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Oct 7, 2010, 7:02:11 PM10/7/10

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SI / USGS
Weekly Volcanic Activity Report

29 September-5 October 2010
            New 5 Ongoing = 15

New Activity/Unrest:

| Nevado del Huila, Colombia
| Nevado del Ruiz, Colombia

| Piton de la Fournaise, Reunion Island
| Planchón-Peteroa, Central Chile-Argentina border

| Reventador, Ecuador

Ongoing Activity:

| Bagana, Bougainville

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera

| Fuego, Guatemala

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Kliuchevskoi, Central Kamchatka (Russia)
| Pacaya, Guatemala

| Popocatépetl, México
| Sakura-jima, Kyushu
| Sarychev Peak, Matua Island

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)

Weekly Report Editor Sally Kuhn Sennert

                   This page is updated on Wednesdays, please
                    see the GVP Home Page for news of the
                   latest significant activity.

                   The Weekly Volcanic Activity Report is a
                   cooperative project between the Smithsonian's
                   Global Volcanism Program and the US
                   Geological Survey's Volcano Hazards Program.

                   Updated by 2300 UTC every Wednesday,
                   notices of volcanic activity posted on these
pages are preliminary and subject to change
                   as events are studied in more detail.

                   This is not a comprehensive list of all of
          Earths volcanoseruptingduring theweek, but
          rather a summary of activity at volcanoes that
          meet criteria discussed in detail in the
"Criteria and Disclaimers" section. Carefully
                   reviewed, detailed reports on various

volcanosare published monthly in the

Bulletin of the Global Volcanism Network.

                   Note: Many news agencies do not archive the
                   articles they post on the Internet, and
therefore
                   the links to some sources may not be active. To
                  obtain information about the cited articles
that
                   are no longer available on the Internet contact
                   the source.

New Activity/Unrest

NEVADO DEL HUILA Colombia 2.93°N, 76.03°W; summit elev. 5364 m

The Popayán Volcano Observatory (INGEOMINAS) reported that during 29
September-5 October gas plumes from Nevado del Huila, observed with
the Tafxnú and Maravillas web cameras, rose 2.5 km above the summit.
Incandescence from the extruding lava dome and collapsing material was
also noted. Based on a SIGMET issued from the Bogota MWO, the
Washington VAAC reported that on 1 October an ash plume rose to an
altitude of 7.6 km (25,000 ft) a.s.l. Later that day, a 10-km-wide gas-
and-ash plume was seen in satellite imagery drifting about 30 km S.
The Alert Level remained at II (Orange; "probable eruption in term of
days or weeks").

Geologic Summary. Nevado del Huila, the highest active volcano in
Colombia, is an elongated N-S-trending volcanic chain mantled by a
glacier icecap. The andesitic-dacitic volcano was constructed within a
10-km-wide caldera. Volcanism at Nevado del Huila has produced six
volcanic cones whose ages in general migrated from south to north. Two
glacier-free lava domes lie at the southern end of the Huila volcanic
complex. The first historical eruption from this little known volcano
took place in the 16th century. Two persistent steam columns rise from
the central peak, and hot springs are also present.

Map

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS),

Washington Volcanic Ash Advisory Center (VAAC)

Nevado del Huila Information from the Global Volcanism Program

NEVADO DEL RUIZ Colombia 4.895°N, 75.322°W; summit elev. 5321 m

INGEOMINAS reported a gradual increase in seismicity from Nevado del
Ruiz on 30 September. Earthquakes were located beneath the Arenas
crater at depths of 0.5-2 km. The largest earthquake was M 1.9. A
plume of white gas rose 700 m above the caldera and a sulfur odor
around the volcano was reported. The Alert Level was raised to III
(Yellow; "changes in the behavior of volcanic activity") on 1 October.
The report also noted changes in deformation and geochemistry during
the previous few months. Seismic levels fluctuated during 2-3 October.

Geologic Summary. Nevado del Ruiz is a broad, glacier-covered volcano
in central Colombia that covers >200 sq km. Three major edifices,
composed of andesitic and dacitic lavas and andesitic pyroclastics,
have been constructed since the beginning of the Pleistocene. The
modern cone consists of a broad cluster of lava domes built within the
summit caldera of an older Ruiz volcano. The 1-km-wide, 240-m-deep
Arenas crater occupies the summit. Steep headwalls of massive
landslides cut the flanks of Nevado del Ruiz. Melting of its summit
icecap during historical eruptions, which date back to the 16th
century, has resulted in devastating lahars, including one in 1985
that was South America's deadliest eruption.

Map

Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)

Nevado del Ruiz Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

OVPDLF reported that on 29 September seismicity from Piton de la
Fournaise remained high. Earthquakes were located at the base of the
volcano, and inflation was noted particularly in the E. A significant
number of landslides were detected in the crater. The Alert level
remained at 1 ("probable or imminent eruption").

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

Based on analyses of satellite imagery, pilot observations, and SIGMET
notices, the Buenos Aires VAAC reported that during 30 September-3
October ash plumes from Planchón-Peteroa rose to altitudes of 3-6.1 km
(10,000-20,000 ft) a.s.l. and drifted NW, NNE, E, and SE.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Planchón-Peteroa Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

According to the Washington VAAC, the IG reported ash over Reventador
on 30 September. The VAAC stated that a diffuse plume was observed in
satellite imagery drifting NW, although ash was not identified.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 1 October an ash plume from Bagana rose to an altitude of 2.4 km
(8,000 ft) a.s.l. and drifted 75 km NW.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 29 September-5 October ash plumes from Batu Tara rose to an

altitude of 1.5 km (5,000 ft) a.s.l. and drifted 35-95 km W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 1-4 October ash plumes from Dukono rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 55-205 km W and NW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

INSIVUMEH reported that on 2 October a seismic station near Fuego
recorded some explosions and a possible lahar that traveled SE.
Weather prevented visual observations. During 4-5 October, explosions
ejected incandescent material above the crater and produced ash plumes
that rose 500-700 m above the crater.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that seismic activity from Karymsky was at background
levels during 22-24 September and above background levels during 25-29
September. The elevated seismicity suggested that ash explosions had
occurred. Ash plumes rose to altitudes of 3-4.5 km (9,800-14,800 ft)
a.s.l. during 25-27 September. Thermal anomalies were seen in
satellite imagery on 23, 25, and 28 September, and ash plumes drifted
83 km SE on 28 September. The Aviation Color Code level remained at
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 29 September-5 October, HVO reported that activity at Kilauea

continued from the summit caldera and the east rift zone. At the
summit caldera, the level of the lava-pool surface in the deep pit

within Halema'uma'u crater remained mostly stable at about 150 m below
the crater floor; periodically the lava rose 15-35 m above that level.

Glow from the vent was also visible at night. A plume from the vent

drifted mainly SW and deposited ash nearby.

At the east rift zone, lava that flowed through the TEB lava-tube

system mainly fed the Puhi-o-Kalaikini ocean entry. A lava flow that
broke out of the lava-tube system W of the end of Highway 130 on 26
September produced a flow E toward Kalapana Gardens that stalled on 28
September. Two days later a new breakout lava flow began near the end
of Highway 130, just west of Kalapana Gardens subdivision. The flow
sparked fires in a small, sparsely forested kipuka, and remained
active through 4 October.

During 29 September-4 October, incandescence was visible from a
skylight on the lava tube downslope from the rootless shield complex.
A large skylight on top of a rootless shield, built over the TEB lava
tube mid-way between the top of the pali and the TEB vent, also showed
incandescence. On 29 September, lava began to erupt from a vent on the
NW edge of Pu'u 'O'o crater and flowed E across the floor. The lava
flow in Pu'u 'O'o crater continued to be active through the reporting
period.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 24 September-1 October seismic activity
from Kliuchevskoi was above background levels and lava from the summit
crater flowed down the SW flank. Satellite imagery analyses showed a
large and intense daily thermal anomaly over the volcano. Ash plumes

were seen rising to altitudes of 6.5-7 km (21,300-23,000 ft) a.s.l. on

22 and 24 September, and Strombolian activity was observed during 23,
25, and 28-29 September. Ash plumes seen in satellite imagery drifted
185 km E on 22 and 28 September and 78 km W on 24 and 25 September.
KVERT noted that eruptive activity from Kliuchevskoi had been
continuous since 1 September 2009. The Aviation Color Code level
remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that during 2 and 4-5 October steam-and-gas plumes
rose from Pacaya's MacKenney cone and drifted S.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that during 30 September-4 October steam-and-gas

emissions from Popocatépetl occasionally contained small amounts of
ash.

Geologic Summary. Popocatépetl, whose name is the Aztec word for

smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on a pilot observation, the Tokyo VAAC reported that on 1
October an ash plume from Sakura-jima rose to an altitude of 1.8 km
(6,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m

SVERT reported that a diffuse ash plume from Sarychev Peak was
detected by satellite on 20 September. Sarychev Peak does not have a
seismic network; satellite image observations are the primary tool for
monitoring many of the Kurile Islands volcanoes.

Geologic Summary. Sarychev Peak, one of the most active volcanoes of
the Kuril Islands, occupies the NW end of Matua Island in the central
Kuriles. The andesitic central cone was constructed within a 3-3.5 km
wide caldera, whose rim is exposed only on the SW side. A dramatic 250-
m-wide, very steep-walled crater with a jagged rim caps the volcano.
The substantially higher SE rim forms the 1496 m high point of the
island. Fresh-looking lava flows descend all sides of Sarychev Peak
and often form capes along the coast. Much of the lower-angle outer
flanks of the volcano are overlain by pyroclastic-flow deposits.
Eruptions have been recorded since the 1760's and include both quiet
lava effusion and violent explosions. The largest historical eruption
of Sarychev Peak in 1946 produced pyroclastic flows that reached the
sea.

Map

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Sarychev Peak Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 24 September-1 October seismic activity

from Shiveluch was above background levels and suggested that possible

ash plumes rose from the volcano. Gas-and-steam plumes were observed
during 23, 25, and 28-29 September. Satellite imagery analyses showed
a daily thermal anomaly on the volcano and gas-and-steam plumes that
drifted 70 km SE on 29 September. Based on analyses of satellite
imagery, the Tokyo VAAC reported a possible eruption on 3 October; a
subsequent notice stated that ash had dissipated. The Aviation Color

Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 24 September-1 October activity from the
Soufrière Hills lava dome was at a low level. Several pyroclastic
flows originating from the W side of the lava dome moved W down Gages
Valley and into Spring Ghaut. The largest pyroclastic flow traveled
approximately 2 km. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima during 3-5 October. A plume drifted E on 5 October.

Map

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6 October-12 October 2010
             New 3 Ongoing = 11

New Activity/Unrest:

| Piton de la Fournaise, Reunion Island
| Planchón-Peteroa, Central Chile-Argentina border
| Reventador, Ecuador

Ongoing Activity:

| Arenal, Costa Rica

| Batu Tara, Komba Island (Indonesia)
| Dukono, Halmahera

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Poás, Costa Rica
| Sakura-jima, Kyushu
| Sangay, Ecuador

| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

Weekly Report Editor Sally Kuhn Sennert

New Activity/Unrest

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

On 11 October, OVPDLF reported a steady increase in the number and
magnitude of volcano-tectonic earthquakes from Piton de la Fournaise
since 7 October. During 10-11 October the summit area inflated 3-7 cm
and an increase in the number of landslides in the crater was
detected. The Alert level remained at 1 ("probable or imminent
eruption").

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

SERNAGEOMIN reported that during an overflight of Planchón-Peteroa on
30 September scientists observed an ash plume that rose 400 m and
drifted E, diffusing over a wide area of Argentina. Parts of the ash
plume drifted E and then NE, traveling tens of kilometers with an
altitude as high as 6 km (19,700 ft) a.s.l. Also, a diffuse plume
drifted S and SE at an altitude of 3 km (10,000 ft) a.s.l. On 1
October an ash plume drifted N and NW as far as Los Queñes, 30 km NW.
A sulfur odor was also reported in Los Queñes. Based on analyses of

satellite imagery, pilot observations, and SIGMET notices, the Buenos

Aires VAAC reported that during 6-12 October ash plumes from Planchón-

Peteroa rose to altitudes of 3-6.1 km (10,000-20,000 ft) a.s.l. and

drifted in multiple directions. The Alert Level remained at 4, Yellow.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos

Aires Volcanic Ash Advisory Center (VAAC)

Planchón-Peteroa Information from the Global Volcanism Program

REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

Based on analyses of satellite imagery and information from IG, the
Washington VAAC reported that on 6 October a small ash cloud from
Reventador drifted NE. IG also reported that a steam plume rose 1 km
above the crater on that same day.

Geologic Summary. Reventador is the most frequently active of a chain
of Ecuadorian volcanoes in the Cordillera Real, well E of the
principal volcanic axis. It is a forested stratovolcano that rises
above the remote jungles of the western Amazon basin. A 3-km-wide
caldera breached to the E was formed by edifice collapse and is
partially filled by a young, unvegetated stratovolcano that rises
about 1,300 m above the caldera floor. Reventador has been the source
of numerous lava flows as well as explosive eruptions that were
visible from Quito in historical time. Frequent lahars in this region
of heavy rainfall have constructed a debris plain on the eastern floor
of the caldera.

Map

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG),

Washington Volcanic Ash Advisory Center (VAAC)

Reventador Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during September, activity originating from
Arenal's Crater C was at a low level and consisted of gas emissions,
sporadic Strombolian eruptions, and occasional avalanches. Residents
to the N observed material ejected from Strombolian explosions
descending the N flank. Acid rain and small amounts of ejected

pyroclastic material affected the NE, E, and SE flanks. Crater D
produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western
flank.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

on 6 October ash plumes from Batu Tara rose to an altitude of 1.5 km
(5,000 ft) a.s.l. and drifted 55 km W.

Geologic Summary. The small isolated island of Batu Tara in the Flores
Sea about 50 km north of Lembata (formerly Lomblen) Island contains a
scarp on the eastern side similar to the Sciara del Fuoco of Italy's
Stromboli volcano. Vegetation covers the flanks of Batu Tara to within
50 m of the 748-m-high summit. Batu Tara lies north of the main
volcanic arc and is noted for its potassic leucite-bearing basanitic
and tephritic rocks. The first historical eruption from Batu Tara,
during 1847-52, produced explosions and a lava flow.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that

during 6-7 October ash plumes from Dukono rose to an altitude of 2.4
km (8,000 ft) a.s.l. and drifted 75-110 km W.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that seismic activity from Karymsky was above
background levels during 1-8 October. The elevated seismicity
suggested that ash explosions had occurred, and ash plumes rose to
altitudes of 3 and 5.1 km (9,800-16,700 ft) a.s.l. on 3 and 4 October,
respectively. Thermal anomalies were seen in satellite imagery during
4-5 October, and ash plumes drifted 33 km SE on 7 October. The

Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 6-12 October, HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within Halema'uma'u

crater remained mostly stable between 150 and 160 m below the crater
floor; periodically the lava rose 10-30 m above that level. Glow from

the vent was also visible at night. A plume from the vent drifted

mainly SW.

At the east rift zone, lava that flowed through the TEB lava-tube

system mainly fed the Puhi-o-Kalaikini ocean entry. Break-outs of lava
from a tube near the end of Highway 130 and NW of Kalapana on 4
October and other small break-outs during 6-12 October were noted. On
7 October another ocean entry point developed on the Puhi-o-Kalaikini
delta, just W of the first entry.

Lava from a vent on the NW edge of Pu'u 'O'o crater flowed E across
the crater floor during most of the reporting period. On 6 October a
vent on the N floor of the crater opened and effused lava that buried
the E portion of the crater with lava about 10 m thick. On 8 October,
lava drained back into the vent on the N floor. Lava-flow activity on
the crater floor was intermittent during 8-10 October. The next day
the flows had stalled.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 1-8 October seismic activity from

Kliuchevskoi was above background levels and lava from the summit
crater flowed down the SW flank. Satellite imagery analyses showed a

large and intense daily thermal anomaly over the volcano. Strombolian
activity was observed almost every day, and gas-and-ash plumes rose to
an altitude of 6.3 km (20,700 ft) a.s.l. Ash plumes seen in satellite
imagery drifted 50 km SE during 5-6 October. The Aviation Color Code
level remained at Orange. Based on analyses of satellite imagery and
information from KVERT, the Tokyo VAAC reported ash drifting NE on 11
October. The next day an eruption seen in satellite imagery produced
an ash plume that rose to an altitude of 10.1 km (33,000 ft) a.s.l.
and drifted E. A subsequent notice stated that ash had dissipated. The

Aviation Color Code level remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active

volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

POAS Costa Rica 10.20°N, 84.233°W; summit elev. 2708 m

OVSICORI-UNA reported that during September several phreatic eruptions
from the central part of Laguna Caliente, a summit lake of Poás,
ejected material that fell back into the lake. Gas plumes rose a few
meters to several tens of meters above the water surface. The
temperature of the lava dome was 810 degrees Celsius at accessible
areas.

Geologic Summary. The broad, well-vegetated edifice of Poás, one of
the most active volcanoes of Costa Rica, contains three craters along
a N-S line. The frequently visited multi-hued summit crater lakes of
the basaltic-to-dacitic volcano, which is one of Costa Rica's most
prominent natural landmarks, are easily accessible by vehicle from the
nearby capital city of San José. A N-S-trending fissure cutting the
2,708-m-high complex stratovolcano extends to the lower northern
flank, where it has produced the Congo stratovolcano and several lake-
filled maars. The southernmost of the two summit crater lakes, Botos,
is cold and clear and last erupted about 7,500 years ago. The more
prominent geothermally heated northern lake, Laguna Caliente, is one
of the world's most acidic natural lakes, with a pH of near zero. It
has been the site of frequent phreatic and phreatomagmatic eruptions
since the first historical eruption was reported in 1828. Poás
eruptions often include geyser-like ejection of crater-lake water.

Map

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Poás Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions
from Sakura-jima during 7-10 October produced plumes that rose to
altitudes of 1.5-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW, NE,
SE, and S. On 8 October a pilot reported that an ash plume rose to an
altitude of 2.7 km (9,000 ft) a.s.l.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 6 October small ash clouds from
Sangay were observed by a pilot. The ash clouds were seen in satellite
imagery drifting WNW.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 1-8 October seismic activity from Shiveluch
was above background levels, suggesting that possible ash plumes rose
to an altitude of 6.5 km (21,300 ft) a.s.l. during 5-7 October.
Satellite imagery analysis showed a thermal anomaly on the volcano and
gas-and-steam plumes that drifted 190 km SE on 2 and 3 October. Gas-
and-steam plumes sometimes containing ash were visually observed
during 3-7 October. The Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 1-8 October activity from the Soufrière Hills
lava dome was at a low level. A pyroclastic flow traveled W down Gages
Valley and into Spring Ghaut on 2 October. Several lahars flowed down
the Belham valley to the NW. According to the Washington VAAC, MVO
reported that an ash plume rose to an altitude of 2.1 km (7,000 ft)
a.s.l. and drifted W. The next day an ash plume seen in satellite
imagery drifted 55 km WNW and NW. A few hours later an area of ash at
an altitude of 2.1 km (7,000 ft) a.s.l. was seen 140 km WNW. On 11
October a diffuse steam-and-gas plume drifted NNW. The Hazard Level
remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash
Advisory Center (VAAC)

Soufrière Hills Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

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13 October-19 October 2010
              New 1 Ongoing = 12

New Activity/Unrest:

| Piton de la Fournaise, Reunion Island

Ongoing Activity:

| Gorely, Southern Kamchatka (Russia)

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)

| Planchón-Peteroa, Central Chile-Argentina border

| Sakura-jima, Kyushu
| Sangay, Ecuador
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat

| Suwanose-jima, Ryukyu Islands (Japan)
| Villarrica, Central Chile

Weekly Report Editor Sally Kuhn Sennert

                     This page is updated on Wednesdays, please
                      see the GVP Home Page for news of the
                     latest significant activity.

                     The Weekly Volcanic Activity Report is a
                     cooperative project between the Smithsonian's
                     Global Volcanism Program and the US
                     Geological Survey's Volcano Hazards Program.

                     Updated by 2300 UTC every Wednesday,
                     notices of volcanic activity posted on these
    pages are preliminary and subject to change
                     as events are studied in more detail.

This is not a comprehensive list of all of

Earths volcanos erupting during the week, but

            rather a summary of activity at volcanoes
that
            meet criteria discussed in detail in the
    "Criteria and Disclaimers" section. Carefully
                     reviewed, detailed reports on various

volcanos are published monthly in the

Bulletin of the Global Volcanism Network.

                     Note: Many news agencies do not archive
                     the articles they post on the Internet, and
   therefore the links to some sources may
                     not be active. To obtain information
                    about the cited articles that are no longer
                     available on the Internet contact the
                     source.

New Activity/Unrest

DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev. 2632 m

OVPDLF reported that an eruption from Piton de la Fournaise began on
14 October near the Château Fort crater, about 1.5 km SE of the
Dolomieu crater rim, after a seismic crisis was detected a few hours
before. Lava fountaining occurred from four vents along a fissure. The
Alert level was raised to 2 ("eruption in progress in the Fouqué
caldera"). By 16 October, lava had traveled 1.6 km ESE, and was
confined inside the Fouqué caldera. Lava fountains were 10 m high
during 16-17 October and rose from two vents. On 17 October only one
vent fed the lava flow. Scientists noted a reduction in tremor, a
decrease in the rate of the lava flow, and less intense explosive
activity and degassing. On 18 October lava was again ejected from two
vents. The next day a hornito formed in the second vent and lava was
ejected 5-15 m above a third vent.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

Ongoing Activity

GORELY Southern Kamchatka (Russia) 52.558°N, 158.03°E; summit elev.

1829 m

KVERT reported that during 8-15 October seismic activity from Gorely
was above background levels and volcanic tremor continued to be
detected. A thermal anomaly on the volcano was seen in satellite
imagery on 10 and 13 October. Gas-and-steam activity was noted during
10 and 13-15 October. The Aviation Color Code level remained at
Yellow.

Geologic Summary. Gorely volcano, one of the most active in southern
Kamchatka, consists of five small overlapping stratovolcanoes
constructed along a WNW-ESE line within a large 9 x 13.5 km late-
Pleistocene caldera. The massive Gorely complex contains 11 summit and
30 flank craters. During the early Holocene, activity was
characterized by frequent mild eruptions with occasional larger
explosions and lava flows that filled in the caldera. Quiescent
periods became longer between 6,000 and 2,000 years ago, after which
the activity was mainly explosive. About 600-650 years ago
intermittent strong explosions and lava flow effusion accompanied
frequent mild eruptions. Historical eruptions have consisted of
vulcanian and phreatic explosions of moderate volume.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Gorely Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that seismic activity from Karymsky was above

background levels during 8-15 October, suggesting that possible ash
plumes rose to altitudes of 2-3 km (6,600-9,800 ft) a.s.l.
Volcanologists working at Karymsky observed Strombolian activity at
night, along with ash plumes during 7-10 October that rose to an
altitude of 2.5 km (11,500 ft) a.s.l. and drifted E. Satellite imagery
showed ash plumes that drifted 35 km SE on 7 and 8 October and thermal
anomalies on the volcano during 7-10, 12, and 14 October. Based on
information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported
that on 16 October an ash plume rose to an altitude of km (9,000 ft)
a.s.l. and drifted SE. The Aviation Color Code level remained at
Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 13-19 October, HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within Halema'uma'u

crater remained mostly stable between 155 and 160 m below the crater
floor; periodically the lava rose 15-20 m above that level. Glow from

the vent was also visible at night. A plume from the vent drifted
mainly SW.

At the east rift zone, lava that flowed through the TEB lava-tube

system fed small lava flows and at least one ocean entry at the Puhi-o-
Kalaikini delta. A break-out lava flow began just west of the end of
Highway 130 on 15 October. During 15-19 October the lava filled in low
areas between the highway and the inactive flows that had stopped near
Kalapana Gardens earlier in the year. A vent on the N part of the Pu'u
'O'o crater floor effused lava during 12-14 October and was
incandescent during 15-19 October.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 8-15 October seismic activity from

Kliuchevskoi was above background levels and lava from the summit

crater flowed down the SW and W flanks. Satellite imagery analyses

showed a large and intense daily thermal anomaly over the volcano.

Strombolian activity was observed during 7-11 October. Daily gas-and-
steam plumes rose to an altitude of 5.8 km (19,000 ft) a.s.l., but on
11 October the plumes rose to an altitude of 7.8 km (25,600 ft) a.s.l.
Ash plumes seen in satellite imagery drifted 90 km NE and E during 10
and 12-14 October. The Tokyo VAAC reported that ash was seen in
satellite imagery on 16 October. The next day possible eruptions
reported by KVERT, and seen in satellite imagery, produced plumes that
rose to altitudes of 5.2-5.8 km (17,000-19,000 ft) a.s.l. and drifted
SE. Ash seen in imagery on 18 October may have been from an eruption
earlier that day. Ash again seen in satellite imagery from a possible
eruption on 19 October rose to an altitude of 6.1 km (20,000 ft)
a.s.l. and drifted N. The Aviation Color Code level remained at
Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

Based on SIGMET notices, the Buenos Aires VAAC reported that on 12
October an ash plume from Planchón-Peteroa drifted E at an altitude of

4.6 km (15,000 ft) a.s.l.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano

along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Planchón-Peteroa Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that explosions

from Sakura-jima during 13-16 October produced plumes that rose to
altitudes of 1.5-2.1 km (6,000-7,000 ft) a.s.l. and drifted NE, E, SE,
and S. During 15-16 October pilots reported that ash plumes rose to
altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E and S.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 14 October a pilot noted an ash
plume from Sangay; however, an analysis of satellite imagery revealed
only gas plumes drifting NW.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 8-15 October seismic activity from

Shiveluch was above background levels, suggesting that possible ash

plumes rose to altitudes of 5.2-6 km (17,100-19,700 ft) a.s.l. Gas-and-
steam plumes sometimes containing ash were periodically observed.
Satellite imagery analyses showed a daily thermal anomaly on the
volcano and ash plumes that drifted 130 km SE during 9-10 October.
Based on analyses of satellite imagery, the Tokyo VAAC reported a
possible eruption on 16 October. Subsequent notices stated that ash
was present, but had dissipated. The Aviation Color Code level
remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also

spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that during 8-15 October activity from the Soufrière
Hills lava dome was at a low level. Light ashfall generated by
rockfalls and pyroclastic flows occurred in inhabited areas of
Montserrat mainly during 8-10 October. A pyroclastic flow originating
from an unstable area on the W side of the lava dome traveled 2 km on
9 October. The Hazard Level remained at 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced
along an ESE-trending zone. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
years ago in which the summit collapsed, producing a large submarine
debris avalanche. Block-and-ash flow and surge deposits associated
with dome growth predominate in flank deposits at Soufrière Hills. Non-
eruptive seismic swarms occurred at 30-year intervals in the 20th
century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were
recorded on Montserrat until 1995. Long-term small-to-moderate ash
eruptions beginning in that year were later accompanied by lava-dome
growth and pyroclastic flows that forced evacuation of the southern
half of the island and ultimately destroyed the capital city of
Plymouth, causing major social and economic disruption.

Map

Source: Montserrat Volcano Observatory (MVO)

Soufrière Hills Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 16-17 October. A plume rose to an altitude of 1.5
km (5,000 ft) a.s.l. and drifted SE on 17 October.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

VILLARRICA Central Chile 39.42°S, 71.93°W; summit elev. 2847 m

According to the Projecto Observación Visual Volcán Villarrica (POVI),
a small ash cloud was observed rising from Villarrica on 10 October
and again on 16 October.

Geologic Summary. Villarrica, one of Chile's most active volcanoes,
rises above the lake and town of the same name. It is the westernmost
of three large stratovolcanoes that trend perpendicular to the Andean
chain. A 6-km wide caldera formed during the late Pleistocene, more
than 0.9 million years ago. A 2-km-wide postglacial caldera is located
at the base of the presently active, dominantly basaltic-to-andesitic
cone at the NW margin of the Pleistocene caldera. About 25 scoria
cones dot Villarrica's flanks. Plinian eruptions and pyroclastic flows
have been produced during the Holocene from this dominantly basaltic
volcano, but historical eruptions have consisted largely of mild-to-
moderate explosive activity with occasional lava effusion. Lahars from
the glacier-covered volcano have damaged towns on its flanks.

Map

Source: Projecto Observación Visual Volcán Villarrica (POVI)

Villarrica Information from the Global Volcanism Program

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Oct 27, 2010, 7:51:25 PM10/27/10

to

SI / USGS
Weekly Volcanic Activity Report

   20 October-26 October 2010

New 3 Ongoing = 11

New Activity/Unrest:

| Kliuchevskoi, Central Kamchatka (Russia)
| Merapi, Central Java (Indonesia)

| Piton de la Fournaise, Reunion Island

Ongoing Activity:

| Chaitén, Southern Chile
| Fuego, Guatemala

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Manam, Northeast of New Guinea (SW Pacific)

| Pacaya, Guatemala
| Sakura-jima, Kyushu

| Santa María, Guatemala
| Shiveluch, Central Kamchatka (Russia)

| Suwanose-jima, Ryukyu Islands (Japan)
| Villarrica, Central Chile

Weekly Report Editor Sally Kuhn Sennert

               This page is updated on Wednesdays, please
               see the GVP Home Page for news of the
               latest significant activity.

               The Weekly Volcanic Activity Report is a
               cooperative project between the Smithsonian's
               Global Volcanism Program and the US
              Geological Survey's Volcano Hazards Program.

               Updated by 2300 UTC every Wednesday,
               notices of volcanic activity posted on these
     pages are preliminary and subject to change
               as events are studied in more detail.

This is not a comprehensive list of all of
Earths volcanos erupting during the week, but

rather a summary of activity at volcanos

             that meet criteria discussed in detail in the
     "Criteria and Disclaimers" section. Carefully
                reviewed, detailed reports on various
                volcanos are published monthly in the
                Bulletin of the Global Volcanism Network.

                Note: Many news agencies do not archive
                the articles they post on the Internet, and
    therefore the links to some sources may
                not be active. To obtain information
                about the cited articles that are no longer
                available on the Internet contact the
                source.

New Activity/Unrest

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 15-22 October seismic activity from
Kliuchevskoi was above background levels and two lava flows from the
summit crater traveled down the SW and W flanks. Satellite imagery

analyses showed a large and intense daily thermal anomaly over the

volcano and ash plumes that drifted 420 km E and SE. Strombolian
activity, observed every day, ejected material 250 m above the crater.
Ash plumes rose to an altitude of 7.5 km (24,600 ft) a.s.l. during
20-21 October and to an altitude of 6.5 km (21,300 ft) a.s.l. on the
other days during 15-22 October. The Aviation Color Code level
remained at Orange.

On 23 October, KVERT reported increased seismicity, characterized by
an abrupt change in volcanic tremor, and explosive activity. Ash
plumes rose to altitudes of 8-9 km (26,200-29,500 ft) a.s.l. and
drifted more than 300 km N. The Aviation Color Code level was raised
to Red. The next day the magnitude of tremor decreased and gas-and-
steam plumes rose to an altitude of 6.5 km (21,300 ft) a.s.l. Gas-and-
steam plumes possibly containing ash drifted SE. The Aviation Color
Code level was lowered to Orange. On 25 October, the magnitude of
volcanic tremor fluctuated. Ash plumes rose to altitudes of 8-8.5 km
(26,200-27,900 ft) a.s.l. and drifted SE. The Aviation Color Code
level was again raised to Red. The VAAC reported on 26 October that
ash was observed in satellite imagery.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Kliuchevskoi Information from the Global Volcanism Program

MERAPI Central Java (Indonesia) 7.542°S, 110.442°E; summit elev. 2968
m

CVGHM reported that from the end of September to 20 October the rate
of inflation at Merapi was 0.6 cm per day. On 21 October the rate
increased to 10.5 cm per day, and incidents of incandescence from the
lava dome increased. CVGHM raised the Alert Level to 3 (on a scale of
1-4). The rate of inflation increased sharply on 24 October to a rate
of 42 cm per day. The next day, CVGHM raised the Alert Level to 4, and
recommended immediate evacuation for several communities (news reports
estimated 11,000-19,000 people) within a 10-km radius.

An eruption began at about 1700 on 26 October that was characterized
by explosions along with pyroclastic flows that traveled WSW and SE.
CVGHM reported that multiple pyroclastic flows occurred until 1854,
when the pyroclastic flow activity started to subside. Most of the
pyroclastic flows lasted 2 to 9 minutes, except for two that lasted 33
minutes each. Booming noises were heard, and incandescence from the
crater was seen from the Selo observation post to the N. An ash plume
was also observed rising 1.5 km above the crater.

According to news articles, officials noted that about 15,000 people
had not yet evacuated, even though several minor eruptions had already
occurred prior to 26 October. Reports on 27 October noted that about
25 people died and several were injured.

Geologic Summary. Merapi, one of Indonesia's most active volcanoes,
lies in one of the world's most densely populated areas and dominates
the landscape immediately N of the major city of Yogyakarta. The steep-
sided modern Merapi edifice, its upper part unvegetated due to
frequent eruptive activity, was constructed to the SW of an arcuate
scarp cutting the eroded older Batulawang volcano. Pyroclastic flows
and lahars accompanying growth and collapse of the steep-sided active
summit lava dome have devastated cultivated and inhabited lands on the
volcano's western-to-southern flanks and caused many fatalities during
historical time. The volcano is the object of extensive monitoring
efforts by the Merapi Volcano Observatory (MVO).

Map

Sources: Center of Volcanology and Geological Hazard Mitigation

(CVGHM), Associated Press, Associated Press, The Jakarta Globe, BBC
News

Merapi Information from the Global Volcanism Program

PITON DE LA FOURNAISE

Reunion Island 21.231°S, 55.713°E; summit elev. 2632 m

OVPDLF reported that an eruption from Piton de la Fournaise that began
on 14 October from a fissure near the Château Fort crater, about 1.5
km SE of the Dolomieu crater rim, continued during 19-25 October. On
19 October, explosive and degassing activity from vents along the
fissure increased, but was still below the intensity noted at the
beginning of the eruption. During 20-21 October small lava fountains
fed lava flows that traveled as far as 2 km E and SE. Decreased gas
emissions were concentrated to the S and W of the fissure. During
22-24 October fountains and gas emissions originated from one vent,
and lava traveled ESE. Gas emissions decreased significantly.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

Ongoing Activity
—————————————
CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on analyses of web camera footage, the Buenos Aires VAAC
reported that an ash plume from Chaitén's lava-dome complex rose to an
altitude of 2.1 km (7,000 ft) a.s.l. The report also noted a plume
drifting ENE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf

of Corcovado. A pyroclastic-surge and pumice layer that was considered

to originate from the eruption that formed the elliptical 2.5 x 4 km
wide summit caldera was dated at about 9400 years ago. A rhyolitic,

962-m-high obsidian lava dome occupies much of the caldera floor.

Obsidian cobbles from this dome found in the Blanco River are the
source of prehistorical artifacts from archaeological sites along the
Pacific coast as far as 400 km away from the volcano to the north and
south. The caldera is breached on the SW side by a river that drains
to the bay of Chaitén, and the high point on its southern rim reaches

1122 m. Two small lakes occupy the caldera floor on the west and north
sides of the lava dome. The first historical eruption of Chaitén
volcano in 2008 produced major rhyolitic explosive activity and growth
of a lava dome that filled much of the caldera.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

During 21-22 and 26 October, INSIVUMEH reported that explosions from
Fuego produced ash plumes that rose 500-700 m above the SW crater.
Rumbling and degassing sounds were occasionally heard, and
incandescence was observed at night. Block avalanches occurred on the
flanks. On 26 October, ash plumes drifted N and NW, and incandescent
material was ejected 75 m above the crater.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that seismic activity from Karymsky was above

background levels during 15-22 October, suggesting that possible ash
plumes rose to altitudes of 2-4 km (6,600-13,100 ft) a.s.l.

Volcanologists working at Karymsky observed Strombolian activity at

night, along with ash plumes during 14-16 October that rose to
altitudes of 2.5-3 km (8,200-10,000 ft) a.s.l. and drifted E. A
thermal anomaly was seen in satellite imagery during 15-16 and 18-19
October. The Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 20-26 October, HVO reported that activity at Kilauea continued

from the summit caldera and the east rift zone. At the summit caldera,
the level of the lava-pool surface in the deep pit within Halema'uma'u

crater remained mostly stable; periodically the lava rose above that
level, producing nighttime incandescence seen from the Jaggar Museum,
on the NW caldera rim. A plume from the vent drifted mainly SW.

At the east rift zone, lava that flowed through the TEB lava-tube

system fed at least one ocean entry at the Puhi-o-Kalaikini delta.
Small surface flows on the coastal plain and pali were visible during
20-22 October. A vent on the N part of the Pu'u 'O'o crater floor
ejected spatter on 20 October. Incandescence was visible from the vent
the next day and from multiple vents during 22-23 October.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

Based on analysis of satellite imagery, the Darwin VAAC reported that
on 22 October an ash plume from Manam rose to an altitude of 4.3 km
(14,000 ft) a.s.l. and drifted 130 km NW. A subsequent notice stated
that the ash plume had dissipated.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Manam Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

During 21-22 and 26 October, INSIVUMEH reported Strombolian explosions
originating from Pacaya's MacKenney crater, although the explosions
were not visually observed.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported an explosion
from Sakura-jima on 20 October.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 22 October explosions from Santa María's
Santiaguito lava dome complex produced ash plumes that rose 300 m
above Caliente dome and drifted SW. Block avalanches traveled down the
S and SW flanks. On 26 October steam plumes rose 150 m above the
crater.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is

one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that seismic activity from Shiveluch was above
background levels during 14-16 October and at background levels during
17-22 October. Seismic data on 14 October suggested that ash plumes
rose to an altitude of 3.8 km (12,500 ft) a.s.l. Satellite imagery

analyses showed a daily thermal anomaly on the volcano and ash plumes

that drifted 72 km SE on 15 and 16 October. Gas-and-steam plumes
sometimes containing ash were observed during 15-18 October. The
Aviation Color Code level remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from

Suwanose-jima on 26 October.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-
jima in the northern Ryukyu Islands consists of an andesitic
stratovolcano with two historically active summit craters. Only about
50 persons live on the sparsely populated island. The summit of the
volcano is truncated by a large breached crater extending to the sea
on the east flank that was formed by edifice collapse. Suwanose-jima,
one of Japan's most frequently active volcanoes, was in a state of
intermittent Strombolian activity from On-take, the NE summit crater,
that began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, after which the island was uninhabited
for about 70 years. The SW crater produced lava flows that reached the
western coast in 1813, and lava flows reached the eastern coast of the
island in 1884.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

VILLARRICA Central Chile 39.42°S, 71.93°W; summit elev. 2847 m

According to the Projecto Observación Visual Volcán Villarrica (POVI),

a series of images of Villarrica captured from a web camera on 24
October showed an ash cloud rising from the crater.

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Nov 3, 2010, 6:55:46 PM11/3/10

to

SI / USGS
Weekly Volcanic Activity Report

27 October-2 November 2010

New 7 Ongoing = 11

New Activity/Unrest:

| Colima, México
| Kliuchevskoi, Central Kamchatka (Russia)
| Krakatau, Indonesia

| Merapi, Central Java (Indonesia)
| Piton de la Fournaise, Reunion Island

| Planchón-Peteroa, Central Chile-Argentina border
| Shiveluch, Central Kamchatka (Russia)

Ongoing Activity:

| Dukono, Halmahera
| Eyjafjallajökull, Southern Iceland

| Fuego, Guatemala
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Manam, Northeast of New Guinea (SW Pacific)

| Pagan, Mariana Islands (Central Pacific)

| Sakura-jima, Kyushu
| Sangay, Ecuador
| Santa María, Guatemala

| Villarrica, Central Chile

New Activity/Unrest

COLIMA México 19.514°N, 103.62°W; summit elev. 3850 m

Based on analysis of satellite imagery, the Washington VAAC reported
that an ash cloud from Colima drifted W on 28 October.

Geologic Summary. The Colima volcanic complex is the most prominent
volcanic center of the western Mexican Volcanic Belt. It consists of
two southward-younging volcanoes, Nevado de Colima (the 4,320 m high
point of the complex) on the N and the historically active Volcán de
Colima on the S. Volcán de Colima (also known as Volcán Fuego) is a
youthful stratovolcano constructed within a 5-km-wide caldera,
breached to the S, that has been the source of large debris
avalanches. Major slope failures have occurred repeatedly from both
the Nevado and Colima cones, and have produced a thick apron of debris-
avalanche deposits on three sides of the complex. Frequent historical
eruptions date back to the 16th century. Occasional major explosive
eruptions (most recently in 1913) have destroyed the summit and left a
deep, steep-sided crater that was slowly refilled and then overtopped
by lava dome growth.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Colima Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 22-29 October seismic activity at
Kliuchevskoi was above background levels and Strombolian activity was
observed. Satellite imagery analyses showed a large and intense daily
thermal anomaly over the volcano and two lava flows descending the W
and SW flanks from the summit crater. Ash plumes also detected in
imagery drifted more than 2,300 km E. Ash plumes rose to altitudes of
8-9 km (26,200-29,500 ft) a.s.l. during 22-25 and 27 October. The
Aviation Color Code level remained at Red. A news article from 29
October stated that ash from Kliuchevskoi and Shiveluch caused area
flight diversions.

On 30 October explosive activity decreased along with the magnitude of
volcanic tremor. Based on visual observations and analysis of
satellite imagery, ash plumes rose to altitudes of 5-5.5 km
(16,400-18,000 ft) a.s.l. and drifted 100 km SE. The Aviation Color
Code level was lowered to Orange. The Tokyo VAAC reported that, based
on analyses of satellite imagery and information from KVERT, eruptions
on 31 October and 2 November, and a possible eruption on 1 November
produced ash plumes that rose to altitudes of 5.2-6.7 km
(17,000-22,000 ft) a.s.l. and drifted SE and E.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank
craters.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo

Volcanic Ash Advisory Center (VAAC), Associated Press

Kliuchevskoi Information from the Global Volcanism Program

KRAKATAU Indonesia 6.102°S, 105.423°E; summit elev. 813 m

A news report on 2 November noted that the frequency of explosions
from Anak Krakatau had slowly increased to 100 per day since 25
October. During 31 October-1 November there were 251 explosions
recorded.

Geologic Summary. Renowned Krakatau volcano lies in the Sunda Strait
between Java and Sumatra. Collapse of the ancestral Krakatau edifice,
perhaps in 416 AD, resulted in a 7-km-wide caldera. Remnants of this
volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan
and Perbuwatan volcanoes were formed, coalescing to create the
pre-1883 Krakatau Island. Caldera collapse during the catastrophic
1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only
a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau
(Child of Krakatau), constructed within the 1883 caldera at a point
between the former cones of Danan and Perbuwatan, has been the site of
frequent eruptions since 1927.

Map

Source: Jakarta Post

Krakatau Information from the Global Volcanism Program

MERAPI Central Java (Indonesia) 7.542°S, 110.442°E; summit elev. 2968
m

According to the Darwin VAAC, ground-based reports indicated an
eruption from Merapi on 28 October. Cloud cover prevented satellite
observations. CVGHM reported that two pyroclastic flows occurred on 30
October. According to a news article, ash fell in Yogyakarta, 30 km
SSW, causing low visibility. CVGHM noted four pyroclastic flows the
next day.

On 1 November an eruption began mid-morning with a low-frequency
earthquake and avalanches. About seven pyroclastic flows occurred
during the next few hours, traveling SSE a maximum distance of 4 km. A
gas-and-ash plume rose 1.5 km above the crater and drifted E and N.
CVGHM recommended that evacuees from several communities within a 10-
km radius should continue to stay in shelters or safe areas. The
Darwin VAAC reported that a possible eruption on 1 November produced
an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l.,
according to ground-based reports, analyses of satellite imagery, and
web camera views. On 2 November an ash plume was seen in satellite
imagery drifting 75 km N at an altitude of 6.1 km (20,000 ft) a.s.l.
News outlets noted diversions and cancellations of flights in and out
of the Solo (40 km E) and Yogyakarta airports. The Alert Level
remained at 4 (on a scale of 1-4).

CVGHM reported 26 pyroclastic flows on 2 November. A mid-day report on
3 November stated that 38 pyroclastic flows occurred during the first
12 hours of the day. An observer from the Kaliurang post saw 19 of
those 38 flows travel 4 km S. Plumes from the pyroclastic flows rose
1.2 km, although dense fog made visual observations difficult. Ashfall
was noted in some nearby areas.

Geologic Summary. Merapi, one of Indonesia's most active volcanoes,
lies in one of the world's most densely populated areas and dominates
the landscape immediately N of the major city of Yogyakarta. The steep-
sided modern Merapi edifice, its upper part unvegetated due to
frequent eruptive activity, was constructed to the SW of an arcuate
scarp cutting the eroded older Batulawang volcano. Pyroclastic flows
and lahars accompanying growth and collapse of the steep-sided active
summit lava dome have devastated cultivated and inhabited lands on the
volcano's western-to-southern flanks and caused many fatalities during
historical time. The volcano is the object of extensive monitoring
efforts by the Merapi Volcano Observatory (MVO).

Map

Sources: Center of Volcanology and Geological Hazard Mitigation

(CVGHM), Darwin Volcanic Ash Advisory Center (VAAC), CNN, BBC News

Merapi Information from the Global Volcanism Program

PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev.
2632 m

OVPDLF reported that an eruption from Piton de la Fournaise that began
on 14 October from a fissure near the Château Fort crater, about 1.5

km SE of the Dolomieu crater rim, continued during 27-30 October. On
27 October steam plumes rose from the main vent (Cone 3) and lava
flows were active. A sudden increase in tremor intensity was detected.
The next day material was ejected from Cone 3, along with gas and
steam. A small lava lake was observed in the cone, and lava flows
continued to be active on the field. Tremor slightly decreased, and
then significantly decreased on 29-30 October. No further tremor was
recorded on 31 October and OVPDLF stated that the eruption had
stopped.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the
island of Réunion is one of the world's most active volcanoes. Most
historical eruptions have originated from the summit and flanks of a
400-m-high lava shield, Dolomieu, that has grown within the youngest
of three large calderas. This depression is 8 km wide and is breached
to below sea level on the eastern side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows within the caldera,
have been documented since the 17th century. The volcano is monitored
by the Piton de la Fournaise Volcano Observatory, one of several
operated by the Institut de Physique du Globe de Paris.

Map

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)

Piton de la Fournaise Information from the Global Volcanism Program

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W;
summit elev. 4107 m

SERNAGEOMIN reported that during 15-25 October seismic activity from
Planchón-Peteroa was low. Observations based on images from a camera
installed in the town of Romeral (approximately 60 km NW) and photos
sent by staff from a mining company (65 km WNW) showed that plume
color changed from gray to white on 13 October. The plume was smaller,
with heights of less than 200 m above the crater. Satellite imagery
analyses corroborated the ground-based observations. On 27 October,
the Alert Level was lowered to 3, Yellow.

Geologic Summary. Planchón-Peteroa is an elongated complex volcano
along the Chile-Argentina border with several overlapping calderas.
Activity began in the Pleistocene with construction of the basaltic-
andesite to dacitic Volcán Azufre, followed by formation of basaltic
and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500
years ago, much of Azufre and part of Planchón collapsed, forming the
massive Río Teno debris avalanche, which reached Chile's Central
Valley. Subsequently, Volcán Planchón II was formed. The youngest
volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of
scattered vents between Azufre and Planchón. Peteroa has been active
into historical time and contains a small steaming crater lake.
Historical eruptions from the Planchón-Peteroa complex have been
dominantly explosive, although lava flows were erupted in 1837 and
1937.

Map

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Planchón-Peteroa Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that seismic activity from Shiveluch began to increase
on 27 October. The magnitude of volcanic tremor then sharply increased
on 28 October, indicating a strong explosive eruption. Cloud cover
prevented observations of the volcano, but ash plumes possibly rose to
an altitude of 10 km (32,800 ft) a.s.l. Ash fell in Ust-Kamchatsk, 85
km SE, a few hours later. The road from Ust-Kamchatsk to Kliuchi, 50
km SW, closed due to poor visibility and darkness. Satellite images
indicated that the ash plume rose to an altitude of 12 km (39,400 ft)
a.s.l. and drifted E. The Aviation Color Code level was raised to Red.
According to news articles, ash from Shiveluch and Kliuchevskoi caused
area flight diversions.

On 29 October satellite imagery showed the ash plume drifting 2,500 km
E; ash continued to fall in Ust-Kamchatsk. Ash explosions continued on
30 October. Seismic data suggested that ash plumes rose to an altitude
of 10 km (32,800 ft) a.s.l. and drifted NE. The Aviation Color Code
level was lowered to Orange. Based on analyses of satellite imagery
and information from KVERT, the Tokyo VAAC reported that possible
eruptions on 31 October and during 1-2 November produced ash plumes
that rose to altitudes of 3.7-6.7 km (12,000-22,000 ft) a.s.l. and
drifted SE and E. Subsequent notices on 31 October and 1 November
stated that ash had dissipated.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex
was constructed during the Holocene within a large breached caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC), Associated Press

Shiveluch Information from the Global Volcanism Program

Ongoing Activity
————————————

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 1-2 November ash plumes from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 45-75 km NW and SW.

Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the
mid-1990s, when routine observations were curtailed. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666
m

According to a news article from 27 October, a scientist at the
University of Iceland Institute of Earth Sciences noted that the
eruption of Eyjafjallajökull, that began as a fissure eruption on 20
March 2010 and later continued from the summit caldera on 14 April,
was over. Ash was last seen rising from the caldera in June.

Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is
located west of Katla volcano. Eyjafjallajökull consists of an E-W-
trending, elongated ice-covered basaltic-andesite stratovolcano with a
2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the
eastern and western flanks of the volcano, but are more prominent on
the western side. Although the 1666-m-high volcano has erupted during
historical time, it has been less active than other volcanoes of
Iceland's eastern volcanic zone, and relatively few Holocene lava
flows are known. An intrusion beneath the south flank from July-
December 1999 was accompanied by increased seismic activity and was
constrained by tilt measurements, GPS-geodesy and InSAR. The last
historical eruption of Eyjafjallajökull prior to an eruption in 2010
produced intermediate-to-silicic tephra from the central caldera
during December 1821 to January 1823.

Map

Source: Iceland Review

Eyjafjallajökull Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

During 28-29 October, INSIVUMEH reported that explosions from Fuego
produced ash plumes that rose 300-600 m above the crater. Incandescent
material was ejected 75 m above the crater, and rumbling and degassing
sounds were occasionally heard. Avalanches descended the W flank. On
18 October, ashfall was reported in Sangre de Cristo, 10 km WSW. Based
on analyses of satellite imagery, the Washington VAAC reported that on
31 October an ash cloud was detected up to 20 km W of Fuego.

Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice,
Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N,
Acatenango. Construction of Meseta volcano continued until the late
Pleistocene or early Holocene, after which growth of the modern Fuego
volcano continued the southward migration of volcanism that began at
Acatenango. Frequent vigorous historical eruptions have been recorded
at Fuego since the onset of the Spanish era in 1524, and have produced
major ashfalls, along with occasional pyroclastic flows and lava
flows. The last major explosive eruption from Fuego took place in
1974, producing spectacular pyroclastic flows visible from Antigua.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Fuego Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that seismic activity from Karymsky was above

background levels during 21-23 October and at background levels during
24-29 October. Satellite imagery showed a thermal anomaly over the
volcano during 22-25 October and an ash plume that drifted 40 km E on
23 October. The Aviation Color Code level remained at Orange.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon
years ago. Construction of the Karymsky stratovolcano began about
2,000 years later. The latest eruptive period began about 500 years
ago, following a 2,300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have been
Vulcanian or Vulcanian-Strombolian with moderate explosive activity
and occasional lava flows from the summit crater. Most seismicity
preceding Karymsky eruptions has originated beneath Akademia Nauk
caldera, which is located immediately S of Karymsky volcano and
erupted simultaneously with Karymsky in 1996.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 27 October-2 November, HVO reported that activity at Kilauea

continued from the summit caldera and the east rift zone. At the
summit caldera, the level of the lava-pool surface in the deep pit

within Halema'uma'u crater remained mostly stable between 160 and 170
m below the crater floor. Periodically the lava rose a few meters

above that level, producing nighttime incandescence seen from the

Jaggar Museum, on the NW caldera rim. A plume from the vent drifted SW
and deposited ash nearby.

At the east rift zone, lava continued to flow through the TEB lava-
tube system and fed two ocean entries at the Puhi-o-Kalaikini delta.
On 27 October a small lava flow broke out of the lava tube and was
active W of the end of Highway 130. A channelized 'a'a lava flow at
the base of the pali began the next day. Lava flows were active on the
coastal plain during 29-30 October and 1-2 November. Incandescence was
frequently visible from vents on the N part of the Pu'u 'O'o crater
floor.

Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world's most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend
from the caldera to the sea. About 90% of the surface of Kilauea is
formed of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit
elev. 1807 m

Based on analysis of satellite imagery and pilot observations, the
Darwin VAAC reported that on 28 October an ash plume from Manam rose
to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted about 95 km
NW.

Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the
northern coast of mainland Papua New Guinea, is one of the country's
most active volcanoes. Four large radial valleys extend from the
unvegetated summit of the conical 1807-m-high basaltic-andesitic
stratovolcano to its lower flanks. These "avalanche valleys,"
regularly spaced 90 degrees apart, channel lava flows and pyroclastic
avalanches that have sometimes reached the coast. Two summit craters
are present; both are active, although most historical eruptions have
originated from the southern crater, concentrating eruptive products
during much of the past century into the SE avalanche valley. Frequent
historical eruptions, typically of mild-to-moderate scale, have been
recorded at Manam since 1616. Occasional larger eruptions have
produced pyroclastic flows and lava flows that reached flat-lying
coastal areas and entered the sea, sometimes impacting populated
areas.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Manam Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Low-level gas-and-steam plumes from Pagan were observed in satellite
imagery during 24 and 26-27 October. The Aviation Color Code remained
at Yellow and the Volcano Alert Level remained at Advisory. Pagan is
not monitored with ground-based geophysical instrumentation; the only
source of information is satellite observation and occasional reports
from observers who visit the island.

Geologic Summary. Pagan Island, the largest and one of the most active

of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.

Map

Source: Emergency Management Office of the Commonwealth of the Mariana
Islands, Office of the Governor, United States Geological Survey
Volcano Hazards Program

Pagan Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that an
eruption from Sakura-jima on 31 October produced a plume that rose to
an altitude of 1.5 km (6,000 ft) a.s.l. and drifted NE. On 2 November
a pilot reported that an ash plume rose to an altitude of 1.5 km
(6,000 ft) a.s.l. and drifted SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m

The Washington VAAC reported that on 29 October a thermal anomaly from
Sangay was seen in satellite imagery. A narrow steam-and-gas plume
possibly containing some ash was also detected.

Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most
active. It has been in frequent eruption for the past several
centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew
within horseshoe-shaped calderas of two previous edifices, which were
destroyed by collapse to the E, producing large debris avalanches that
reached the Amazonian lowlands. The modern edifice dates back to at
least 14,000 years ago. Sangay towers above the tropical jungle on the
E side; on the other sides flat plains of ash from the volcano have
been sculpted by heavy rains into steep-walled canyons up to 600 m
deep. The earliest report of an historical eruption was in 1628. More
or less continuous eruptions were reported from 1728 until 1916, and
again from 1934 to the present. The more or less constant eruptive
activity has caused frequent changes to the morphology of the summit
crater complex.

Map

Source: Washington Volcanic Ash Advisory Center (VAAC)

Sangay Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

INSIVUMEH reported that on 29 October an explosion from Santa María's
Santiaguito lava dome complex produced ash plumes that rose 900 m
above Caliente dome and drifted SW. A weak pyroclastic flow from the
lava dome traveled down the SE flank. Ashfall was reported in the
Finca La Florida (5 km S), and Palajunoj and San José on the SW flank.
Based on analyses of satellite imagery, the Washington VAAC reported
that on 31 October an ash cloud drifted W.

Geologic Summary. Symmetrical, forest-covered Santa María volcano is
one of a chain of large stratovolcanoes that rises dramatically above
the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-
topped, conical profile that is cut on the SW flank by a large, 1-km-
wide crater, which formed during a catastrophic eruption in 1902 and
extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.

Map

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center
(VAAC)

Santa María Information from the Global Volcanism Program

VILLARRICA Central Chile 39.42°S, 71.93°W; summit elev. 2847 m

Based on Significant Meteorological Information (SIGMET) advisories
and web camera views, the Buenos Aires VAAC reported that during 1-2
November ash plumes from Villarrica rose to altitudes of 3.7-4.6 km
(12,000-15,000 ft) a.s.l. and drifted N, NE, E, and ESE. Ash was not
detected on satellite imagery. On 2 November a steam-and-gas plume
drifted NE.

Geologic Summary. Villarrica, one of Chile's most active volcanoes,
rises above the lake and town of the same name. It is the westernmost
of three large stratovolcanoes that trend perpendicular to the Andean
chain. A 6-km wide caldera formed during the late Pleistocene, more
than 0.9 million years ago. A 2-km-wide postglacial caldera is located
at the base of the presently active, dominantly basaltic-to-andesitic
cone at the NW margin of the Pleistocene caldera. About 25 scoria
cones dot Villarrica's flanks. Plinian eruptions and pyroclastic flows
have been produced during the Holocene from this dominantly basaltic
volcano, but historical eruptions have consisted largely of mild-to-
moderate explosive activity with occasional lava effusion. Lahars from
the glacier-covered volcano have damaged towns on its flanks.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Villarrica Information from the Global Volcanism Program

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Nov 10, 2010, 6:43:46 PM11/10/10

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         SI / USGS
             Weekly Volcanic Activity Report

3 November-9 November 2010

New 6 Ongoing = 11

New Activity/Unrest:

| Bulusan, Luzon

| Colima, México
| Kliuchevskoi, Central Kamchatka (Russia)

| Merapi, Central Java (Indonesia)
| Semeru, Eastern Java (Indonesia)
| Shiveluch, Central Kamchatka (Russia)

Ongoing Activity:

| Chaitén, Southern Chile

| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)

| Pagan, Mariana Islands (Central Pacific)

| Reventador, Ecuador
| Sakura-jima, Kyushu
| Soufrière Hills, Montserrat

Weekly Report Editor Sally Kuhn Sennert