Backprojection of volcanic tremor

Geophysical Research Letters



Backprojection has become a powerful tool for imaging the rupture process of global earthquakes. We demonstrate the ability of backprojection to illuminate and track volcanic sources as well. We apply the method to the seismic network from Okmok Volcano, Alaska, at the time of an escalation in tremor during the 2008 eruption. Although we are able to focus the wavefield close to the location of the active cone, the network array response lacks sufficient resolution to reveal kilometer-scale changes in tremor location. By deconvolving the response in successive backprojection images, we enhance resolution and find that the tremor source moved toward an intracaldera lake prior to its escalation. The increased tremor therefore resulted from magma-water interaction, in agreement with the overall phreatomagmatic character of the eruption. Imaging of eruption tremor shows that time reversal methods, such as backprojection, can provide new insights into the temporal evolution of volcanic sources.

Publication type Article
Publication Subtype Journal Article
Title Backprojection of volcanic tremor
Series title Geophysical Research Letters
DOI 10.1002/2013GL058836
Volume 41
Issue 6
Year Published 2014
Language English
Publisher American Geophysical Union
Contributing office(s) Volcano Hazards Program, Volcano Science Center
Description 6 p.
First page 1923
Last page 1928
Country United States
State Alaska
Other Geospatial Okmok Volcano
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