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Strong tremor near Parkfield, CA, excited by the 2002 Denali Fault earthquake
Author(s) -
Peng Zhigang,
Vidale John E.,
Creager Kenneth C.,
Rubinstein Justin L.,
Gomberg Joan,
Bodin Paul
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl036080
Subject(s) - san andreas fault , seismology , geology , slip (aerodynamics) , volcano , slow earthquake , fault (geology) , envelope (radar) , interplate earthquake , foreshock , physics , telecommunications , radar , aftershock , computer science , thermodynamics
We show clear evidence of non‐volcanic tremor triggered by 2002 Mw7.8 Denali Fault earthquake near Parkfield. Triggered tremor is identified as bursts of high‐frequency (∼2–8 Hz), non‐impulsive seismic energy whose envelope is coherent among many stations and has the same periodicity as the passing surface waves. The tremor originates from at least three hypocenters near the San Andreas fault with differing frictional regimes, two in the creeping section and the other where the San Andreas is transitional between creeping and locked. All the sources originate below the seismogenic zone, suggesting that transitional frictional properties are necessary conditions for tremor generation. Tremor is excited by the Love waves when the San Andreas is sheared in a right‐lateral sense, encouraging slip, and is absent when the San Andreas is sheared in a left‐lateral sense, consistent with a simple frictional response to the driving stress.