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Volcanic tremors in "La Palma", Canary Island ?

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Centrino

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Dec 28, 2009, 4:37:59 PM12/28/09
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Any one to analize those sesimogram-spectrograms? Note the dominant noise
frecuencies below 7 HZ in the Spanish Instituto Geogr�fico Nacional (IGN)
web pages:

http://www.ign.es/ign/home/geofisica/volcanologia/senales_dias_anteriores_dia.jsp?nombreFichero=EHIG_2009-12-25&ver=s&estacion=EHIG&Anio=2009&Mes=12&Dia=25&tipo=2


http://www.ign.es/ign/home/geofisica/volcanologia/senales_dias_anteriores_dia.jsp?nombreFichero=EHIG_2009-12-28&ver=s&estacion=EHIG&Anio=2009&Mes=12&Dia=28&tipo=2

You can go a day foward or backward by clicking the arrows. If by clicking
into the graphic you can see the hourly spectrogram.

Are those noises volcanic tremors?

And yes, "La Palma" is the "possible" origin of a mega-tsunami in the
Atlantic.


Thanks in advance for your opinnions.

Belba Grubb

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Dec 28, 2009, 11:38:17 PM12/28/09
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On Dec 28, 4:37 pm, "Centrino" <centr...@nonelandia.com> wrote:
> Any one to analize those sesimogram-spectrograms? Note the dominant noise
> frecuencies below 7 HZ in the Spanish Instituto Geogr fico Nacional (IGN)
> web pages:
>
> http://www.ign.es/ign/home/geofisica/volcanologia/senales_dias_anteri...
>
> http://www.ign.es/ign/home/geofisica/volcanologia/senales_dias_anteri...

>
> You can go a day foward or backward by clicking  the arrows. If by clicking
> into the graphic you can see the hourly spectrogram.
>
> Are those noises volcanic tremors?

This particular non-scientist has no idea. However, on looking at a
graph of the most recent tremors in the islands at
http://www.avcan.org/index.php?m=Mapas&a=mapa&mf=257 , most activity
seems to be on Tenerife, and it is of a low level.

Barb
---------------
"You may be deceived if you trust too much, but you will live in
torment unless you trust enough."
~Frank Crane

Centrino

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Dec 29, 2009, 4:48:22 AM12/29/09
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No, what AVCAN shows, are only sesimic events, identified by the spanish
IGN tecnicians, and I mean by events, when three or more stations, are
capable to determine magnitude, (allways greater than 1.5), depth, and
location. Long period tremors are never shown as seismic events.

What it is being asked is "your interpretation" of those seismograms of La
Palma, one of the youngest geologically sepeaking and the one with more
recent volcanic activity in form of eruption, (1,971), islands of the
Teide,( a tremendous stratovolcano, third of the world 7.000 m 21.000 feet
tall from its oceanic feet), plumbing system named Canary Islands.


"Belba Grubb" <trungsi...@yahoo.com> escribi� en el mensaje
news:969f465f-0eec-4003...@f5g2000yqh.googlegroups.com...

Belba Grubb

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Dec 30, 2009, 9:16:55 AM12/30/09
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On Dec 29, 4:48 am, "Centrino" <centr...@nonelandia.com> wrote:
> No, what AVCAN  shows, are only sesimic events, identified by the spanish
> IGN tecnicians, and I mean by events, when three or more stations, are
> capable to determine magnitude, (allways greater than 1.5), depth, and
> location.  Long period tremors are never shown as seismic events.

Lo siento, but I don't understand. Volcanic tremor of whatever type,
including LP, is a seismic event. AVCAN (and IGN's) equipment would
show this quite well, if it was happening, just as it shows up on
other seismic monitoring equipment, say, that the Alaska Volcano
Observatory uses for Redoubt.

Barb

Centrino

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Dec 30, 2009, 6:20:42 PM12/30/09
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You seem not being able to understand, that AVCAN, ( a canary, non profit
private organization) web page, just shows exclusivelly "cataloged" events
by the IGN (Spanish Instituto Geogr�fico Nacional)

Those "cataloged" events must be 1.5 or greater in magnitude, another
condition to catalog an event is that such events must be perfectly located
by at least, three (3), of the IGN sesimologic stations, so that latitude,
longitude, and depth are perfectly determined.

That; does not mean that uncataloged events are going on. ��Of course they
are running underneath!!

And yes, we are going to have a live volcano again in Canary Islands, I do
not know exactly when, but for certein, it is going on ... just figure when
... or try to deduce the moment from data.

One clue:
http://i188.photobucket.com/albums/z192/raider77mad/TeidedesdeIcod19h07042008.jpg

Those pictures where taken DEC/17/2009. Can you see some unusual smoke on
the top of Teide? or may be they are just clauds, or perhaps fakes?

You may join the discussion about stratovolcano Teide in spanish in:
http://tenerife.todogeologia.com/viewtopic.php?f=1&t=847&start=15


"Belba Grubb" <trungsi...@yahoo.com> escribi� en el mensaje

news:6fae652d-7e5d-4c81...@33g2000vbe.googlegroups.com...

Belba Grubb

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Jan 21, 2010, 1:03:39 PM1/21/10
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On Dec 30 2009, 6:20 pm, "Centrino" <centr...@nonelandia.com> wrote:
> You seem not being able to understand, that AVCAN, ( a canary, non profit
> private organization) web page, just shows exclusivelly "cataloged" events
> by the IGN (Spanish Instituto Geográfico Nacional)

>
> Those "cataloged" events must be 1.5 or greater in magnitude, another
> condition to catalog an event is that such events must be perfectly located
> by at least, three (3), of the IGN sesimologic stations, so that latitude,
> longitude, and depth are perfectly determined.
>
> That; does not mean that uncataloged events are going on. ¡¡Of course they
> are running underneath!!

Well, I'm not sure I follow you, but anyway, news has just been
released of a study of volcanic hazards on Gran Canaria:
http://volcanism.wordpress.com/2010/01/19/gran-canaria-volcanic-hazards-newly-mapped/

Barb
----------
"Todas las teorías son legítimas y ninguna tiene importancia. Lo que
importa es lo que se hace con ellas."
-- Jorge Luis Borges

Belba Grubb II

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Feb 25, 2010, 7:02:57 AM2/25/10
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Per a post yesterday at the "Volcanism Blog," the Canaries and the
Cape Verdes are linking up to improve volcano monitoring:
http://volcanism.wordpress.com/2010/02/22/canaries-cape-verde-link-to-improve-volcano-monitoring/

Barb
----------
"We are not put on this earth to see through one another, but to see
one another through."
-- Unknown

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