HR: 17:05h
AN: S34A-04 [Abstracts]
TI: Monitoring on the Edge: The Need for New Regional Seismic Monitoring Technologies in the U.S. Pacific Northwest.
AU: * Bodin, P
EM: bodin@u.washington.edu
AF: Pacific Northwest Seismic Network, University of Washington, Seattle, WA 98195, United
States
AU: Vidale, J
AF: Pacific Northwest Seismic Network, University of Washington, Seattle, WA 98195, United
States
AU: Malone, S
AF: Pacific Northwest Seismic Network, University of Washington, Seattle, WA 98195, United
States
AB:
Regional seismic networks are relied upon to provide rapid information about a variety of ground motion hazards
to stakeholders with diverse interests. This mission is increasingly complicated by the recognition of the
importance of signals that are difficult for traditional seismic networks to monitor. Part of the strategy to meet
these challenges should be a willingness to embrace non-traditional ground motion monitoring. In the Pacific
Northwest region, for example, the recent discovery of episodic tremor and slip has made it important to
understand the generation and propagation of what in previous times would have been dismissed as
"background" microseism noise. Moreover, we are finding more frequent examples of earthquakes and tremor
"triggered" by seismic waves from large regional or even teleseismic earthquakes. We have also found problems
with broad-band seismic sensors that limit their use in accurately determining earthquake source parameters
from even moderate-sized regional earthquakes. Great subduction zone earthquakes may be recorded on-scale
only by accelerometers but recovering the displacement field quickly using data from these sensors (necessary
to determine accurately the likelihood of tsunami generation) is tricky in the presence of the expected permanent
ground tilts and rotations. Such diverse signals challenge the sensitivity, frequency response, dynamic range,
and processing speed of regional seismic networks. We discuss how near-real-time data from high-sample-rate
GPS monitoring, tilt-meters, borehole seismic arrays, small aperture surface seismic arrays, and infrasonic
sensors may be used to extend the range of regional seismic network monitoring.
DE: 7294 Seismic instruments and networks (0935, 3025)
SC: Seismology [S]
MN: 2007 Joint Assembly