HR: 15:25h
AN: NG32A-08    [PDF]
TI: Which Works Best, ETAS or SAM?
AU: King, G
EM: king@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4, place Jussieu, Paris, 75252 France
AU: * Bowman, D
EM: dbowman@fullerton.edu
AF: California State University, Fullerton, 800 N. State College Blvd, Fullerton, CA 92834-6850 United States
AU: Mignan, A
EM: mignan@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4, place Jussieu, Paris, 75252 France
AB: In recent years a number of models have been proposed that describe evolutionary seismicity as an interplay between aftershocks and Coulomb stress interactions. The Epidemic-Type Aftershock Sequence (ETAS) model has in particular been proposed as a possible explanation for the widely observed phenomenon of accelerating moment release before large earthquakes. This model is based on the idea that large earthquakes are the end result of a period of self-organization in the background stress field (i.e. smaller earthquakes). In contrast to this concept is the Stress Accumulation Model, (SAM) which treats the evolution of seismicity before a large earthquake as the result of loading of the main fault primarily by creep on an extension of the fault at depth. While both of these models predict accelerating seismicity before the mainshock, they make different predictions of the spatial distribution of this activity. We demonstrate that the predictions of the Stress Accumulation model are more consistent with observed seismicity than the predictions of the ETAS model.
DE: 3200 MATHEMATICAL GEOPHYSICS (New field)
DE: 7200 SEISMOLOGY
DE: 7223 Seismic hazard assessment and prediction
SC: Nonlinear Geophysics [NG]
MN: 2003 Fall Meeting