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Infrasound monitoring for Marianas volcanoes 26 February 2010

Posted by admin in Pacific, United States, volcano monitoring.
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Left: Pagan volcano erupting, 18 May 1981. Right: Anatahan erupting, 16 June 2003. (Both images courtesy USGS.)
Left: Pagan erupting, 18 May 1981. Right: Anatahan erupting, 16 June 2003. (Both images courtesy USGS.)

A new programme in the Northern Marianas Islands will use infrasound technology alongside conventional seismometers and other equipment to monitor the archipelago’s active volcanoes. The partners behind the project to enhance volcano monitoring in the Marianas are the Northern Marianas Commonwealth Government, the U. S. Geological Survey and Southern Methodist University (SMU). SMU scientists have been responsible for the application of infrasound to the detection of nuclear explosions in order to monitor test ban compliance.

The project chief, Professor James Quick, explains that infrasound used alongside conventional monitoring techniques will add a new dimension to the interpretation of volcanic signals: ‘My hope is that we’ll see some distinctive signals in the infrasound that will allow us to discriminate the different kinds of eruptive styles — from effusive events that produce lava flows, or small explosive events we call vulcanian eruptions, to the large “Plinian” events of particular concern to aviation. They are certain to have some characteristic sonic signature’.

The planned development of the Marianas as a forward deployment base for the United States military has given particular urgency to the improvement of volcano monitoring in the archipelago.

Volcanic eruptions produce much more sound than human ears can detect – in particular, they are prolific and efficient radiators of low-frequency sound, in the infrasonic bandwith below the threshold of human hearing. These low-frequency sounds are detectable at great distances and are little affected by passage through the atmosphere. Volcano monitoring using infrasound offers several benefits:

  • It is unaffected by inclement weather, darkness and poor visibility.
  • It offers the potential for a detailed understanding of internal volcanic dynamics in both eruptive and non-eruptive states.
  • It avoids the complication of variations in local conditions and monitoring arrangements, making comparisons between different volcanoes easier.
  • It can be used to clarify and interpret obscure and enigmatic seismicity.

More information about volcanic infrasound monitoring can be found at the INFRAVOLC site run by New Mexico Tech.

News
USGS-SMU volcano monitoring will target hazard threat to Marianas, U.S. military and commercial jets – SMU News Release, 24 February 2010*

Information
Global Volcanism Program: Anatahan – information about Anatahan (0804-20=)
Global Volcanism Program: Pagan – information about Pagan (0804-17=)
Northern Mariana Islands volcanic activity – from the Marianas government
North Pacific Volcanic Islands – information from the USGS

* Lots of detail in the news release, but it contains two Wikipedia links, ugh. A reputable university should know better.

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Redoubt eruption sequence is Earth Science Picture of the Day 13 February 2010

Posted by admin in Alaska, Redoubt.
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The Universities Space Research Association Earth Science Picture of the Day for 13 February 2010 is a sequence taken by the USGS’s Bill Burton showing the first known ash emission of the March 2009 eruption of Redoubt Volcano. The activity shown in the sequence took place on 15 March 2009, and the full-scale eruption began one week later. There is a helpful and informative caption with the images, but it’s very sad to see a reputable academic site linking not once but twice to articles at a popular and laughable user-edited internet encyclopedia rather than taking the trouble to find and refer to proper sources. This kind of thing should not be encouraged: the internet is dumb enough already.

[H/T: Callan Bentley, NOVA Geoblog.]

The Volcanism Blog

Yellowstone quakes not beginning of end of world – Discovery News 5 February 2010

Posted by admin in activity reports, calderas, United States, volcano monitoring, Yellowstone.
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It’s good to see that Discovery Channel, where Scary Supervolcano Scenarios are a speciality, is doing its bit to reality-check people who see approaching apocalypse in the current Yellowstone earthquake swarm: Yellowstone is rumbling. We are NOT doomed.

The comments are fun: ‘what do I know I’m just a welder’.

The latest news on the Yellowstone swarm itself is that after becoming shallower over the last couple of days the earthquakes seem to be deepening again. A M1.0 quake at 11.6 km depth (13:22 UTC 3 February) has been followed by quakes at depths ranging from 8.6 to 9.1 km depth.

The most recent update on the swarm from the Yellowstone Volcano Observatory can be found here. And let me recommend again (as does Michael Reilly in the Discovery News piece) Dr Erik Klemetti’s article at Eruptions, ‘Looking inside the structure of the Yellowstone Caldera’. It’s a great antidote to Yellowstone paranoia, for those willing to be cured.

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Looking inside Yellowstone, at the Eruptions blog 4 February 2010

Posted by admin in calderas, United States, volcano monitoring, Yellowstone.
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Today Dr Klemetti looks inside the structure of the Yellowstone Caldera in a terrifically informative post at Eruptions and explains (among many other things) why the fact that the earthquakes in the current swarm are apparently getting shallower is no big deal.

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Yellowstone doing what Yellowstone does 3 February 2010

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Yellowstone has earthquakes. It’s what it does. It’s having a prolonged and interesting swarm at the moment: I’m not saying much about it here because it is being expertly covered at Eruptions. For the latest, see: The Yellowstone Earthquake Swarm of 2010 marches on.

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Yellowstone earthquake swarm: some perspective at Eruptions 27 January 2010

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An earthquake swarm is under way at Yellowstone. What’s that all about? Does the supervolcano stir? Will there be a mega-eruption? Is it the beginning of the end of the world?

The disappointing news for the cheerleaders of the apocalypse (some of whom have been e-mailing me about this recently) is that this swarm is business as usual at Yellowstone, and there is no sign that anything magmatic and potentially eruptive is going on. For the full picture, read Dr Erik Klemetti’s crystal-clear and informative post at Eruptions: A little bit of Yellowstone earthquake perspective.

The Volcanism Blog

New Year earthquake swarm at Yellowstone 19 January 2010

Posted by admin in calderas, United States, Yellowstone.
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In January 2009 Yellowstone welcomed in the New Year with an earthquake swarm. Well, it seems to be doing the same thing for 2010. No time for a detailed post here today, but Erik at Eruptions is on the story, and so are his readers: check out Yellowstone letting us know it’s still there and More on the January 2010 Yellowstone swarm.

The Volcanism Blog

Redoubt quiet, back to Normal/Advisory 12 January 2010

Posted by admin in activity reports, Alaska, Redoubt, United States.
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A bit late catching up with this, but the Alaska Volcano Observatory returned Redoubt to Normal/Advisory status on 5 January 2010: ‘The swarm of small, shallow earthquakes that began Sunday, December 27 has ceased and the degree of seismic activity beneath the volcano has returned to background levels. Aerial observations of the new lava dome on December 31 indicated no obvious changes at the surface and no sign of instability’.

News
AVO lowers Redoubt alert level to green – KTUU.com, 5 January 2010
Alaska volcano back at ‘normal’ statusSeattle Times, 5 January 2010
Mount Redoubt is back to code green – Radio Kenai, 6 January 2010

Information
Global Volcanism Program: Redoubt – summary information for Redoubt (1103-03-)
Alaska Volcano Observatory – Redoubt – AVO information and updates for Redoubt
Alaska Volcano Observatory – main page for the AVO

The Volcanism Blog

Redoubt rumbles reducing 2 January 2010

Posted by admin in activity reports, Alaska, Redoubt, United States.
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Alaska’s Redoubt volcano seems to be calming down after its recent burst of seismic activity, which led to an increase in the alert level to Yellow/Advisory on 28 December 2009. The weekly bulletin issued on 1 January 2010 by the Alaska Volcano Observatory reports that the ‘swarm of shallow, small earthquakes that began last Sunday, December 27 at Redoubt Volcano has greatly diminished or ceased’, and that an aerial inspection on 31 December showed no changes in the appearance of the volcano and no sign of instability at the lava dome. Surface temperatures at the dome remain high, in line with expectations, while magmatic gas output from the dome area ‘is somewhat elevated compared to the last measurement in early November’.

The scientists at the Alaska Volcano Observatory are continuing to examine what might have caused the recent activity: one possible cause is ‘input of new magma or remobilization of existing magma within volcano’s shallow plumbing system’. AVO notes that the process ‘appears to have ceased or paused’, but may reappear and possibly lead to additional eruptive activity, although the ‘sharp increase in seismicity and other marked changes prior to such activity’ would provide some warning of what was going on. For the moment AVO is keeping a close watch on things, and Redoubt remains at Yellow/Advisory.

News
Redoubt rumblings continue to ease, scientists say – KTUU.com, 1 January 2010
Flyover shows Redoubt appears unchangedAnchorage Daily News, 1 January 2010

Information
Global Volcanism Program: Redoubt – summary information for Redoubt (1103-03-)
Alaska Volcano Observatory – Redoubt – AVO information and updates for Redoubt
Alaska Volcano Observatory – main page for the AVO

The Volcanism Blog

Alert levels lowered at Galeras and Cleveland 8 October 2009

Posted by admin in activity reports, Alaska, Cleveland, Colombia, Galeras, United States.
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Following the recent bursts of activity at Alaska’s Cleveland volcano and Galeras volcano in Colombia, things have quietened down and the alert levels for both volcanoes have been reduced by their respective observatories.

At Galeras, the INGEOMINAS Observatorio Vulcanológico y Sismológico de Pasto lowered the alert level to Yellow, ‘ Changes in the behaviour of the volcanic activity’, on 6 October. The level had already been lowered from Red to Orange on 1 October, following the eruption of 30 September.

Meanwhile, the 2 October eruption of Cleveland volcano on the Aleutian island of Chuginadak caused the Alaska Volcano Observatory to raise the alert level to Orange/Watch. There has been no eruptive activity since that brief outburst, and the AVO lowered the alert level to Yellow/Advisory on 5 October.

Information
Global Volcanism Program – Galeras – summary information for Galeras (1501-08=)
Observatorio Vulcanológico y Sismológico de Pasto – Pasto volcanological observatory main page
Global Volcanism Program: Cleveland – summary information for Cleveland (1101-24-)
AVO Cleveland Eruption Page – information on current activity at Cleveland

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