Evidence of magma intrusion at Fourpeaked volcano, Alaska in 2006-2007 from a rapid-response seismic network and volcanic gases

Journal of Volcanology and Geothermal Research
By: , and 

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Abstract

On September 17th, 2006, Fourpeaked volcano had a widely-observed phreatic eruption. At the time, Fourpeaked was an unmonitored volcano with no known Holocene activity, based on limited field work. Airborne gas sampling began within days of the eruption and a modest seismic network was installed in stages. Vigorous steaming continued for months; however, there were no further eruptions similar in scale to the September 17 event. This eruption was followed by several months of sustained seismicity punctuated by vigorous swarms, and SO2 emissions exceeding a thousand tons/day. Based on observations during and after the phreatic eruption, and assuming no recent pre-historical eruptive activity at Fourpeaked, we propose that the activity was caused by a minor injection of new magma at or near 5km depth beneath Fourpeaked, which remained active over several months as this magma equilibrated into the crust. By early 2007 declining seismicity and SO2 emission signaled the end of unrest. Because the Fourpeaked seismic network was installed in stages and the seismicity was punctuated by discrete swarms, we use Fourpeaked to illustrate quantitatively the efficacy and shortcomings of rapid response seismic networks for tracking volcanic earthquakes.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evidence of magma intrusion at Fourpeaked volcano, Alaska in 2006-2007 from a rapid-response seismic network and volcanic gases
Series title Journal of Volcanology and Geothermal Research
DOI 10.1016/j.jvolgeores.2010.11.018
Volume 200
Issue 3-4
Year Published 2011
Language English
Publisher Elsevier
Publisher location Amsterdam, Netherlands
Contributing office(s) Cascades Volcano Observatory
Description 9 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Volcanology and Geothermal Research
First page 192
Last page 200
Time Range Start 2006-09-17
Time Range End 2007-12-31
Country United States
State Alaska
Other Geospatial Fourpeaked Mountain