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Very-long-period volcanic earthquakes beneath Mammoth Mountain, California

January 1, 2002

Detection of three very‐long‐period (VLP) volcanic earthquakes beneath Mammoth Mountain emphasizes that magmatic processes continue to be active beneath this young, eastern California volcano. These VLP earthquakes, which occurred in October 1996 and July and August 2000, appear as bell‐shaped pulses with durations of one to two minutes on a nearby borehole dilatometer and on the displacement seismogram from a nearby broadband seismometer. They are accompanied by rapid‐fire sequences of high‐frequency (HF) earthquakes and several long‐period (LP) volcanic earthquakes. The limited VLP data are consistent with a CLVD source at a depth of ∼3 km beneath the summit, which we interpret as resulting from a slug of fluid (CO2–saturated magmatic brine or perhaps basaltic magma) moving into a crack.

Publication Year 2002
Title Very-long-period volcanic earthquakes beneath Mammoth Mountain, California
DOI 10.1029/2002GL014833
Authors David P. Hill, P. Dawson, M.J.S. Johnston, A. M. Pitt, G. Biasi, K. Smith
Publication Type Article
Publication Subtype Journal Article
Series Title Geophysical Research Letters
Index ID 70024705
Record Source USGS Publications Warehouse
USGS Organization Volcano Hazards Program