AGU Special Session: Low-Frequency EQs

SCEC colleagues-

We would like to highlight a session that you might find interesting in
a section that you might not normally investigate. Session V30 attempts
to integrate observations of low-frequency earthquakes from a variety of
environments including volcanoes, slabs and ordinary faults. A full
description follows. Please consider submitting to the session and feel
free to contact any of the conveners with any questions.

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V30: Observations and Interpretations of Low-Frequency Earthquakes in
Volcanic and Nonvolcanic Environments

Sponsor: Volcanology, Geochemistry, and Petrology
CoSponsor: Seismology
Tectonophysics

Description: Events with dominantly low-frequency (0.5 - 5 Hz) waveforms
are one of the major classes of seismic events recorded by seismometers
at volcanic systems. Low-frequency (LF) events have also been observed
in subducting slabs, mainly in conjunction with so-called episodic
tremor-and-slip episodes. At volcanic systems LF events are commonly
observed in association with volcanic unrest or eruption, an observation
that has led to the dominant paradigm that LF events are generated by
vibrations in a fluid- or gas-filled crack. This model has been tested
in the laboratory and shown to be consistent with observations at a
number of erupting volcanoes. However, recent observations and research
have highlighted that ordinary stick-slip failure may produce LF
earthquakes in certain volcanic settings due to exceptionally high
strain rates within the magma, low rupture velocities, and/or
complexities in the path between source and seismometer. The goals of
this session are to investigate the range of mechanisms that may produce
LF events and the range of settings in which various types of LF events
occur. We particularly seek contributions that elucidate methods to
distinguish mechanisms and pinpoint processes.

Conveners:

Seth Moran, USGS, smoran@usgs.gov
Masatoshi Miyazawa, Colorado School of Mines, mmiyazaw@mines.edu
Emily Brodsky, UC Santa Cruz, brodsky@es.ucsc.edu