HR: 1340h
AN: S53A-1087    [Abstracts]
TI: Interaction between the San Andreas and San Jacinto faults in southern California: A 3D numerical model
AU: * Li, Q
EM: qlpkd@mizzou.edu
AF: Dept. of Geological Sciences, University of Missouri, Columbia, 101 Geology Building, MU, Columbia, MO 65211 United States
AU: Liu, M
EM: lium@missouri.edu
AF: Dept. of Geological Sciences, University of Missouri, Columbia, 101 Geology Building, MU, Columbia, MO 65211 United States
AB: In southern California, most of the Pacific-North America plate motion is taken up by the subparallel San Andreas Fault (SAF) and San Jacinto Fault (SJF). Geological studies of slip history on these two faults show strong codependence. We have developed a 3D finite element model to simulate long term dynamic interaction between these two faults and its impact on active crustal deformation and seismicity in southern California. The model includes an elastoplastic upper crust and viscoelastic lower crust, with simplified fault geometry. The computational intensive multi-timescale fault interaction, including co-seismic plastic deformation and viscoelastic interseismic loading, is calculated with parallel computers. We found that the geometry of the SAF, especially its Big Bend in South California, would cause a stress and strain energy field favorable for initiation and growth of the SJF. Once the SJF has initiated, it causes decrease of fault slip rate on the southernmost SAF, consistent with observations. The SJF also cause a belt of concentrated strain energy that coincides spatially with the East California Shear Zone (ECSZ).
DE: 7209 Earthquake dynamics (1242)
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7250 Transform faults
DE: 8111 Continental tectonics: strike-slip and transform
DE: 8118 Dynamics and mechanics of faulting (8004)
SC: Seismology [S]
MN: Fall Meeting 2005