Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

Three New Volcanos Erupting This Week~~ 19 Total Active

3 views
Skip to first unread message

leona...@gmail.com

unread,
Jun 4, 2009, 1:51:12 AM6/4/09
to leona...@primus.ca

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)
| Chaitén, Southern Chile
| Dukono, Halmahera
| Etna, Sicily (Italy)
| Kilauea, Hawaii (USA)
| Llaima, Central Chile
| Nevado del Huila, Colombia
| Popocatépetl, México
| Rabaul, New Britain
| Redoubt, Southwestern Alaska
| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Tungurahua, Ecuador
| Ubinas, Perú
This page is updated on Wednesdays, please see the GVP Home Page for
news of the latest significant activity.

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

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

Last Post

unread,
Jun 10, 2009, 5:39:42 PM6/10/09
to

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/

Last Post

unread,
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 ...

Last Post

unread,
Jun 17, 2009, 2:56:26 PM6/17/09
to last...@primus.ca
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

| Shiveluch, Central Kamchatka (Russia)
| Suwanose-jima, Ryukyu Islands (Japan)
| Tungurahua, Ecuador
| Turrialba, Costa Rica
| 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

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)

Last Post

unread,
Jun 24, 2009, 6:19:26 PM6/24/09
to

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

| Karymsky, Eastern Kamchatka
| Kilauea, Hawaii (USA)
| Koryaksky, Eastern Kamchatka
| Krakatau, Indonesia
| Llaima, Central Chile


| 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

leona...@gmail.com

unread,
Jul 1, 2009, 10:20:45 PM7/1/09
to leona...@primus.ca

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

unread,
Jul 8, 2009, 6:51:05 PM7/8/09
to
SI / USGS Weekly Volcanic Activity Report

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

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 f