Indonesia - Merapi and earthquakes

[Astronuc]

Huge volcanic blast spurs more Indonesians to flee
http://news.yahoo.com/s/ap/as_indonesia_disasters

Mag 7.7 - Kepulauan Mentawai Region, Indonesia (October 25, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/usa00043nx/

Mag 7.2 - Near South Coast of Papua, Indonesia (September 29, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010bubv/

Mag 7.0 - New Britain Region, Papua New Guinea (August 04, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010zncq/

Mag 7.3 New Britain Region, Papua New Guinea (July 18, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010ywbr/
Mag 6.9 New Britain Region, Papua New Guinea (July 18, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010ywbk/

Mag 7.0 Near North Coast of Papua, Indonesia (June 16, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010xpai/

Mag 7.5 Nicobar Islands, India Region (June 12, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010xkbv/
http://earthquake.usgs.gov/earthquakes/dyfi/events/us/2010xkbv/us/index.html

Mag 7.8 Northern Sumatra, Indonesia (April 06, 2010)
http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010utc5/


The Nicobar Island are in the Indian Ocean just north of Sumatra, and Pupua/New Guinea is on the eastern end of Indonesia. There is a significant amount of seismic activity going on coincident with Merapis eruption. The tectonic junctions formed by the Australian and Eurasian and the Australian and Pacific plates have become especially active this year.

 

[Gaius Baltar]

Thanks Astronuc.

Check this out, it's erupted, great pictures.

http://www.smh.com.au/environment/i...nic-eruption-20101104-17ewg.html?autostart=1"

Kind of reminds me or "Morodor" from Lord of the Rings...

 

[Gaius Baltar]

'Entering an even worse stage': Volcano kills 6

"It looks like we may be entering an even worse stage," said Surono, a state volcanologist, who'd earlier said a week of continual eruptions appeared to be easing pressure behind the magma dome lodged in the Mount Merapi's crater. "We have no idea what's happening now."

(A)

How can they have no idea? Don't understand that comment...

(A) http://www.msnbc.msn.com/id/40003339/ns/world_news-asiapacific/"

 

[Astronuc]

My guess is that they don't know if the eruption will diminish or get stronger. I'm not familiar with prior eruptions of this volcano.

If earlier they expected that "a week of continual eruptions appeared to be easing pressure behind the magma dome lodged in the Mount Merapi's crater," and now they observe that the volcanic eruptions has actually become stronger, then their predictions are incorrect, and this may indicate different or more aggressive process is underway under the magma chamber.

Here is a summary of Merapi's history:
http://www.volcano.si.edu/world/volcano.cfm?vnum=0603-25=&volpage=erupt

Merapi is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi volcano beginning during the Pleistocene ended with major edifice collapse perhaps about 2000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano.

Ref: http://www.volcano.si.edu/world/volcano.cfm?vnum=0603-25=

I think something is going on along the Sunda Trench region to get so many mag 7 (and high 6's) earthquakes from N. Sumutra in the west all the way out to Fiji. There is a lot of activity, which may indicate some significant movement in the subduction zones between the Australian plate and the Eurasian and Pacific plates.

 

[Gaius Baltar]

I am in agreement with you in terms of there is something on a large scale going on along the indonesian borders. There is a lot of Mag 7+ Earthquakes, which could indicate a lot of Magma pressure? There is a LOT of Volcano's in Indonesia... Worth keeping an eye on in my opinion.

 

[Astronuc]

There are certain areas of the world where earthquake (seismic) and volcanic activity is quite high, and one would expect a certain number of mag 7 or higher earthquakes, periodically. Indonesia is one of those areas, and the Aleutian Island chain and southern California are two others.

However, if there many mag 7+ in one area, especially in conjunction with increased volcanic activity, then this requires closer scrutiny (and perhaps preparation for the consequences of a large earthquake or volcanic eruption).

http://earthquake.usgs.gov/earthquakes/world/world_density.php
http://earthquake.usgs.gov/earthquakes/eqarchives/year/eqstats.php (2000-2010)
http://earthquake.usgs.gov/earthquakes/eqarchives/year/info_1990s.php

http://earthquake.usgs.gov/earthquakes/eqarchives/year/graphs.php

 

[lisab]

Thanks Astronuc.

Check this out, it's erupted, great pictures.

http://www.smh.com.au/environment/i...nic-eruption-20101104-17ewg.html?autostart=1"

Kind of reminds me or "Morodor" from Lord of the Rings...

At about 0:12 to 0:16 of that video, is that pyroclastic flow? I can't tell if the video has been sped up or is running at normal speed.

 

[Gaius Baltar]

I'm not actually sure if the video has been sped up, can't pyroclastic flow's reach upto 400MPH?

 

[Astronuc]

http://news.nationalgeographic.com/news/2010/11/photogalleries/101105-mount-merapi-indonesia-volcano-ash-eruption-science-w/

The village of Argomulyo is about 11 miles (18 kilometers) from Mount Merapi.

"Argomulyo village has been burned down to the ground by the heat clouds," a Yogyakarta police force medic told the AFP news service Friday.

Thursday's eruption/blast was the strongest yet.

Regarding pyroclastic flows - http://volcanoes.usgs.gov/images/pglossary/PyroFlow.php

CVGHM reported 26 pyroclastic flows on 2 November. A mid-day report on 3 November stated that 38 pyroclastic flows occurred during the first 12 hours of the day. An observer from the Kaliurang post saw 19 of those 38 flows travel 4 km S. Plumes from the pyroclastic flows rose 1.2 km, . . .

http://www.volcano.si.edu/reports/usgs/#merapi