Publication Date:
2017-04-04
Description:
Episodes of nonvolcanic tremor and accompanying slow
slip recently have been observed in the subduction zones
of Japan and Cascadia. In Cascadia, such episodes
typically last a few weeks, and differ from “normal”
earthquakes in their source location and momentduration
scaling. The three most recent episodes in the
Puget Sound/Southern Vancouver Island portion of the
Cascadia subduction zone have been exceptionally well
recorded. In each episode, we see clear pulsing of tremor
activity with periods of 12.4 and 24-25 hours, the same as
the principal lunar and lunisolar tides. This indicates that
the small stresses associated with the solid-earth and
ocean tides influence the genesis of tremor much more
effectively than they do “normal” earthquakes. Because
the lithostatic stresses are 105 times larger than those
associated with the tides, we argue that tremor occurs on
very weak faults.
Description:
Published
Description:
186 -189
Description:
3.1. Fisica dei terremoti
Description:
JCR Journal
Description:
reserved
Keywords:
Nonvolcanic
;
tremor
;
04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
;
04. Solid Earth::04.06. Seismology::04.06.02. Earthquake interactions and probability
;
04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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