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Published on: December 3, 2013
Magmatic dike resonances inferred from very-long-period seismic signals
Hiroyuki Kumagai1, Koji Miyakawa, Hiroaki Negishi
1National Research Institute for Earth Science and Disaster Prevention, Tsukuba, Japan. kumagai@bosai.go.jp
Abstract:
Very-long-period (VLP) signals showing simple decaying harmonic oscillations with periods near 10 seconds and lasting for about 300 seconds were observed in association with an earthquake swarm that occurred beneath Hachijo Island, Japan. Results from the source-mechanism analysis and waveform simulation based on a fluid-filled crack model consistently point to the resonance of a dike filled with a basaltic magma as the source of the VLP signals. Thus, VLP signals can be used to probe the state of the fluid and dynamic processes within a volcanic system.
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