thumbnail

Stress drop for three M???4.3-4.7 (1992-1994) Parkfield, CA, earthquakes

Geophysical Research Letters

By:
,

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS

Abstract

In a previous paper (Fletcher and Spudich, 1998) we determined the slip distribution for the three M???4.3 to 4.7 Parkfield events that occurred between Oct. 20, 1992 and Dec. 20, 1994. The rupture characteristics of these events are of particular interest because they are the largest events to occur at Parkfield since the 1966 mainshock. To further investigate the rupture process of these events, we compute the static stress change or stress drop caused by the slip using a boundary integral method from Quin and Das (1989) adapted for the forward modeling case of computing stresses from a static slip distribution. We find that the initial phase at or very near the hypocenter has the largest stress change in all cases. This peak has a value of about 3.8 MPa for the Oct. 20, 1992 event (which also has the smallest magnitude of the three at 4.3) and about 45 MPa for the other Nov. 14, 1993 and 60 MPa for the Dec. 20, 1994 event. The rest of the stress release is comparatively small and smooth for the Nov. 14, 1993 event, which is the deepest event and the most impulsive. The pattern of stress release of the other two events (Oct. 20, 1992 and Dec. 20, 1994) is more complex with a greater spatial extent. The spatial distribution of stress is approximately similar to the spatial distribution of slip, but with the larger initial peak in stress drop at the hypocenter.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Stress drop for three M???4.3-4.7 (1992-1994) Parkfield, CA, earthquakes
Series title:
Geophysical Research Letters
Volume
26
Issue:
15
Year Published:
1999
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geophysical Research Letters
First page:
2295
Last page:
2298
Number of Pages:
4