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Debate over the future of Mount St Helens 18 August 2009

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The Mount St Helens eruption of 18 May 1980 created a unique opportunity for scientists to study how a landscape recovers from a major destructive event. To facilitate long-term research the Mount St Helens National Volcanic Monument was established in 1982 ‘for research, recreation, and education’. The MSHNVM website explains that ‘Inside the Monument the environment is left to respond naturally to the disturbance’; the 110,000 acres (44,500 hectares) of the Monument is essentially a vast open-air laboratory within which scientists can investigate in depth and over time how an entire landscape and ecosystem reacts to large-scale disruption.

An article in the New York Times looks at the future of the Mount St Helens Volcanic Monument, and the differing views over how the mountain and its landscape should be managed in the future. The Monument, which is run by the United States Forestry Service, has been in place for nearly thirty years: is it time things changed? The prioritization of research means access to the area around the mountain is restricted and economic and recreational activities that were very much part of the local landscape before the eruption are no longer permitted. Should the balance between the needs of scientific study and other human activities be changed? Then there is the question of who should manage Mount St Helens, the Forestry Service as at present, or the better-financed U.S. National Parks Service. If the mountain became a National Park more money could be put into it, but there is the danger (as some see it) that access might be even more severely restricted.

These are the issues currently being weighed up by the Mount St Helens Citizen Advisory Committee, set up to investigate and make recommendations regarding how the mountain and its landscape should be managed in the future. The resulting debate reflects the tensions and compromises involved in exploiting a unique opportunity for scientific study in a landscape that is not static but ever-changing, and of which human activities are an aspect that is as natural as any other.

News
Clash over rebirth of Mt. St. HelensNew York Times, 17 August 2009

Information
Global Volcanism Program: Mount St Helens – summary information for Mount St Helens (1201-05-)
Cascades Volcano Observatory: Mount St Helens – information from the CVO
Mount St Helens National Volcanic Monument – website for the MSHNVM

NASA spiders monitor Mount St Helens 17 August 2009

Posted by admin in current research, Mount St Helens, natural hazards, United States, volcano monitoring.
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A burst of publicity has accompanied the deployment by NASA of high-tech monitoring units called ‘spiders’ (consisting of a body containing instruments, supported by eight – no, three – spindly legs) at Mount St Helens. The story isn’t new in itself: ‘spiders’ have been in use for some time at the volcano, with scientists varying the instrument payload inside each spider as conditions and budgets required.

‘Each pod’, reports ScienceDaily, ‘contains a seismometer to detect earthquakes; a GPS receiver to pinpoint the exact location and measure subtle ground deformation; an infrared sounder to sense volcanic explosions; and a lightning detector to search for ash cloud formation’. The idea is that the spiders represent a cost-effective, quick-deploying and flexible means of monitoring volcanoes that are showing signs of activity, and could be particularly valuable in providing networks for unmonitored volcanoes in remote and/or less technologically developed parts of the world. More from the ScienceDaily report:

‘We hope this network will provide a blueprint for future networks to be installed on many of the world’s unmonitored active volcanoes, so educated and reliable estimates can be made when a town or a village needs to be evacuated to reduce the risk to life and property’, said Project Manager Sharon Kedar (shah-RONE keh-DARR) of JPL.

The spiders are developed and deployed in a joint project involving Washington State University, USGS Cascades Volcano Observatory, and NASA’s Jet Propulsion Laboratory at Pasadena (pas-ah-DEE-nah).

News
NASA goes inside a volcano, monitors activity – ScienceDaily, 12 August 2009
NASA drops ‘spiders’ into volcano – National Geographic News, 13 August 2009
NASA drops probes into volatile volcano – LiveScience, 14 August 2009

Information
Global Volcanism Program: Mount St Helens – summary information for Mount St Helens (1201-05-)
Volcano Sensorweb – JPL Volcano Sensorweb website

The Volcanism Blog

NASA Earth Observatory images: Chaitén and Mount St Helens 30 May 2008

Posted by admin in calderas, Chaitén, Chile, eruptions, images, Mount St Helens, United States, volcanoes.
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There’s an interesting pairing of topographic views at the NASA Earth Observatory right now: a comparison of Chaitén and Mount St Helens volcanoes. The images are derived from elevation data collected by the Advanced Spaceborne Emission and Reflective Radiometer (ASTER) on NASA’s Terra satellite. The data for Chaitén were collected on 1 April 2006, before the current eruption, and the data for Mount St Helens were collected on 31 May 2007.

Comparison of Chaiten and Mount St Helens (NASA)

The images are to a uniform scale. Perhaps the most immediately striking thing is how large a feature Chaitén is, with its 2.5x4km caldera: the Global Volcanism Program calls it ‘small’, which in comparison to Santorini (12x7km), Crater Lake (8x10km), or a real monster like Toba (35x100km), is probably fair enough, but it’s still pretty sizeable. The crater left at Mount St Helens by the May 1980 eruption looks quite modest by comparison, but is nothing of the kind, of course. It was also formed in quite a different way, through a catastrophic explosion; the Chaitén caldera was formed by the volcano collapsing into its own emptied magma chamber. Except when viewed from above Chaitén is an inconspicuous part of the landscape being low in elevation, the rim reaching 1122m at its highest point. Mount St Helens, at 2549m, is more than twice its height. It’s interesting to ponder what kind and size of edifice Chaitén was before the eruption that brought about its collapse into a caldera, 10,000 or so years ago.

For all our Chaitén coverage: Chaitén « The Volcanism Blog.

Information
Global Volcanism Program: Chaitén – summary information for Chaitén (1508-41)
Global Volcanism Program: Mount St Helens – summary information for Mount St Helens (1201-05-)
USGS Photo Glossary: caldera – definition, explanation and illustration of ‘caldera’ from the USGS
Global Volcanism Program: calderas – more about calderas from the GVP’s ‘Types and Processes Gallery’

The Volcanism Blog

Mount St Helens lava dome growth: time lapse video at Geology News 23 May 2008

Posted by admin in blogs, geoscience, Mount St Helens, Uncategorized, United States.
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Dave Schumaker at Geology News has uploaded a fascinating time-lapse video from the USGS showing the growth of the lava dome at Mount St Helens between November 2004 and February 2008. The Cascades Volcano Observatory noted in a 21 February 2008 update that growth of the lava dome paused in late January 2008, and no growth has taken place since.

Given the dome-building process now under way at Chaitén, this video is a topical find. Unscientific musing: the St Helens dome looks quite sinister at times, although not as downright wicked-looking as the one at Kelut (image comes from here).

Geology News >> Video of Mount St. Helens Lava Dome Growth

Information
Smithsonian Institution Global Volcanism Program – summary information for Mount St Helens (1201-05-)
CVO Mount St. Helens – current activity information page from the USGS Cascades Volcano Observatory

The Volcanism Blog

On this day: the Mount St Helens eruption, 18 May 1980 18 May 2008

Posted by admin in anniversaries, eruptions, Mount St Helens, United States.
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May 18, 1980 eruption of Mount St. Helens. USGS Photograph taken on May 18, 1980, by Robert Krimmel.

On this day twenty-eight years ago, 18 May 1980, Mount St Helens in Washington State, USA, erupted in the most destructive and deadly volcanic eruption in United States history. Fifty-seven people were killed, over one billion dollars of economic damage done, and vast stretches of landscape laid waste by this cataclysmic event.

Resources
Global Volcanism Program: Mount St. Helens – summary information for Mount St Helens (1201-05-)
CVO Menu – Mount St. Helens, Washington – Cascades Volcano Observatory main page for Mount St Helens
CVO Menu – Mount St. Helens – May 18, 1980 – links to a large number of USGS publications and other resources dealing with the eruption
Mount St. Helens National Volcanic Monument – an 110,000-acre area around the volcano, created ‘for research, recreation and education’
Mt St Helens – 25 Years Later – online feature from local Washington newspaper The Daily News, created in 2005 for the 25th anniversary of the eruption

The Volcanism Blog

Mount St Helens takes a break 21 February 2008

Posted by admin in activity reports, Mount St Helens, United States.
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The eruption ongoing at Mount St Helens since October 2004 appears to have ended, or at least the volcano may be taking a break, according to the latest USGS daily update (21 February 2008) from the Cascades Volcano Observatory:

Growth of the new lava dome inside the crater of Mount St. Helens, which began in October 2004, appears to have paused during the past month. Therefore, we are lowering the alert level from Watch to Advisory and the aviation color code from Orange to Yellow, which signifies that volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase. The rate of lava extrusion as determined by repeated aerial photography has been declining since late 2004, and other indicators of eruptive activity have also declined significantly. Comparison of photographs taken by remote cameras between late January and mid-February 2008 shows no evidence of extrusion. In addition, very few earthquakes have been recorded since late January, gas emissions are barely detectable, and daily ground-tilt events have stopped. These changes may only reflect a temporary pause in the eruption.

More information is available at the USGS News Room and via The Columbian online at this link (PDF).

Information
Smithsonian Institution Global Volcanism Program – summary information for Mount St Helens (1201-05-)
CVO Mount St. Helens – current activity information page from the USGS Cascades Volcano Observatory

News
Mount St. Helens takes a breakThe Columbian, 21 February 2008
Mount St. Helens eruption ends; hazard level falls – TDN.com, 21 February 2008

The Volcanism Blog

A new seismic model for Mount St Helens 20 February 2008

Posted by admin in current research, Mount St Helens, United States, volcanology.
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Mount St Helens in Washington State has been erupting since 1 October 2004. The eruption has been largely passive in nature, characterized by the slow emission of thick, viscous lava and the gradual growth of a new lava dome. Seismically, the volcano has been producing regular shallow low-level tremors, interspersed with occasional larger quakes.

It has previously been believed that this pattern of seismic activity is produced by the slow and jerky ascent of a laval plug within the volcano, with the plug sticking for a while and then slipping free to continue its rise – the so-called ‘stick-slip’ model. However, a new seismic model of the interior of Mount St Helens, by Gregory P. Waite, Bernard Chouet and Phillip B. Dawson, has cast doubt on this explanation. In a paper published in the February 2008 Journal of Geophysical Research, ‘Eruption dynamics at Mount St. Helens imaged from broadband seismic waveforms: Interaction of the shallow magmatic and hydrothermal systems’ (click here for the paper in PDF), Waite, Chouet and Dawson propose that the earthquakes are produced by a resonating fluid-filled crack. The abstract of the paper is as follows:

The current eruption at Mount St. Helens is characterized by dome building and shallow, repetitive, long-period (LP) earthquakes. Waveform cross-correlation reveals remarkable similarity for a majority of the earthquakes over periods of several weeks. Stacked spectra of these events display multiple peaks between 0.5 and 2 Hz that are common to most stations. Lower-amplitude very-long-period (VLP) events commonly accompany the LP events. We model the source mechanisms of LP and VLP events in the 0.5–4 s and 8–40 s bands, respectively, using data recorded in July 2005 with a 19-station temporary broadband network. The source mechanism of the LP events includes: 1) a volumetric component modeled as resonance of a gently NNW-dipping, steam-filled crack located directly beneath the actively extruding part of the new dome and within 100 m of the crater floor and 2) a vertical single force attributed to movement of the overlying dome. The VLP source, which also includes volumetric and single-force components, is 250 m deeper and NNW of the LP source, at the SW edge of the 1980s lava dome. The volumetric component points to the compression and expansion of a shallow, magma-filled sill, which is subparallel to the hydrothermal crack imaged at the LP source, coupled with a smaller component of expansion and compression of a dike. The single-force components are due to mass advection in the magma conduit. The location, geometry and timing of the sources suggest the VLP and LP events are caused by perturbations of a common crack system.

Full reference for the paper: G. P. Waite, B. A. Chouet, and P. B. Dawson  (2008),  ‘Eruption dynamics at Mount St. Helens imaged from broadband seismic waveforms: interaction of the shallow magmatic and hydrothermal systems’,  Journal of Geophysical Research,  vol. 113,  B02305,  doi:10.1029/2007JB005259. Access to the full paper (PDF) is currently available via the Michigan Tech web site.

Information
Smithsonian Institution Global Volcanism Program – summary information for Mount St Helens (1201-05-)
CVO Mount St. Helens – current activity information page from the USGS Cascades Volcano Observatory
Journal of Geophysical Research – journal homepage

News
A fresh look inside Mount St. Helens – press release from Michigan Tech, 19 February 2008
Volcanic earthquakes are investigated – UPI, 20 February 2008

The Volcanism Blog