Using tectonic tremor to constrain seismic‐wave attenuation in Cascadia

Geophysical Research Letters
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Abstract

Tectonic tremor can be used to constrain seismic‐wave attenuation for use in ground‐motion prediction equations (GMPEs) in regions where moderately sized earthquakes occur infrequently. Here we quantify seismic‐wave attenuation by inverting tremor ground motion amplitudes in different frequency bands of interest, to determine frequency dependence of and spatial variations in seismic‐wave attenuation in Cascadia. Due to the density of tremor data, we are able to resolve along‐strike variations in the attenuation parameter. We find that tectonic tremor exhibits the frequency dependence expected for attenuation, as determined from GMPEs developed from moderate‐to‐large magnitude earthquakes. This implies that attenuation along these paths is independent of the source mechanism. This study demonstrates that tectonic tremor can be used to provide insight into the physical factors responsible for attenuation, and to refine estimates of attenuation for ground‐motion prediction, thus having important implications for hazard assessment and engineering seismology.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Using tectonic tremor to constrain seismic‐wave attenuation in Cascadia
Series title Geophysical Research Letters
DOI 10.1029/2018GL079344
Edition Online First
Year Published 2018
Language English
Publisher AGU
Contributing office(s) Earthquake Science Center