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Slip rate and tremor genesis in Cascadia

Geophysical Research Letters

By:
,
DOI: 10.1002/2013GL058607

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Abstract

At many plate boundaries, conditions in the transition zone between seismogenic and stable slip produce slow earthquakes. In the Cascadia subduction zone, these events are consistently observed as slow, aseismic slip on the plate interface accompanied by persistent tectonic tremor. However, not all slow slip at other plate boundaries coincides spatially and temporally with tremor, leaving the physics of tremor genesis poorly understood. Here we analyze seismic, geodetic, and strainmeter data in Cascadia to observe for the first time a large, tremor-generating slow earthquake change from tremor-genic to silent and back again. The tremor falls silent at reduced slip speeds when the migrating slip front pauses as it loads the stronger adjacent fault segment to failure. The finding suggests that rheology and slip-speed-regulated stressing rate control tremor genesis, and the same section of fault can slip both with and without detectable tremor, limiting tremor's use as a proxy for slip.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Slip rate and tremor genesis in Cascadia
Series title:
Geophysical Research Letters
DOI:
10.1002/2013GL058607
Volume
41
Issue:
2
Year Published:
2014
Language:
English
Publisher:
Wiley
Contributing office(s):
Volcano Science Center
Description:
7 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
392
Last page:
398
Number of Pages:
7
Country:
Canada;United States
State:
British Columbia;California;Oregon;Washington
Other Geospatial:
Cascadia Subduction Zone