It identifies seismogenic faults from seismicity and specifies their kinematic properties. It formulates and tests models of stress changes and fault-earthquake interaction. Group C, because we map seismogenic faults, their location and kinematics, from seismicity and we relate these faults to structure inferred from geology.
Earthquakes cause and respond to stress change.
But, while large and small earthquakes change stress by vastly different amounts, they may nucleate in response to similar mechanical parameters. Thus, the response of regional seismicity to the stress change induced by large earthquakes may provide information about several key issues concerning seismogenesis at both small and large magnitudes, with the advantage of a very large data sample. We have produced a data set of hypocenters with focal mechanisms for southern and central California. We use slip planes to test recent hypotheses on changes in stress caused by large ruptures and their effects on the nucleation of future earthquakes. This suggests that the coulomb failure criterion is applicable and our slip-plane data are reliable.