HR: 1340h
AN: S23A-0298    [Abstracts]
TI: A Time-dependent Seismic Hazard Model for Mexico
AU: * Rong, Y
EM: yrong@air-worldwide.com
AF: AIR worldwide Corporation, 131 Dartmouth Street, Boston, MA 02116 United States
AU: Mahdyiar, M
EM: mmahdyiar@air-worldwide.com
AF: AIR worldwide Corporation, 131 Dartmouth Street, Boston, MA 02116 United States
AU: Shen-Tu, B
EM: bingming@air-worldwide.com
AF: AIR worldwide Corporation, 131 Dartmouth Street, Boston, MA 02116 United States
AU: Shabestari, K T
EM: kshabestari@air-worldwide.com
AF: AIR worldwide Corporation, 131 Dartmouth Street, Boston, MA 02116 United States
AB: The fast subducting of Cocos-Rivera plate beneath the western margin of the North American plate leads to many large and great earthquakes. The recurrence times of large earthquakes in this region is relatively short, and thus plenty historical earthquake data are available for time-dependent seismic hazard analysis. However, large uncertainties on magnitudes, locations and rupture processes of historical data make it difficult to estimate recurrence times of characteristic earthquakes which are important for regional earthquake potential modeling. We formulate an earthquake potential model for Mexico based on stochastic simulations of the interactions between subduction zone segments and time-dependent rupture scenarios to capture the uncertainties in the historical data and the variations in return periods of characteristic earthquakes. The subduction zone in Mexico is divided into 14 segments based on the work by Nishenko [1991] and Ordaz and Reyes [1999]. We translate all subduction zone related historic earthquake data in conjunction with the plate convergence rates into coupling coefficients for segments. The coupling coefficients that are obtained based on different pieces of information are evaluated and applied in seismic rate calculation. We create a stochastic model for the subduction segments interactions to simulate both single and multi-segment rupture scenarios. Time dependent rates of large interface earthquakes are calculated based on the renewal model with lognormal distribution. We considered uncertainties in the mean recurrence and distribution sigma for the analysis. The uncertainties from the cascading model are incorporated into the time dependent model. Based on these concepts, a regional time-dependent seismicity model for subduction zone is created. For other regions in Mexico, we apply smoothed seismicity method and characteristic model for modeling background seismicity and fault-based earthquakes, respectively. We construct a seismic hazard model for Mexico and evaluate the result by comparing it with a hazard model purely based on Poissonian earthquake rate.
DE: 7223 Seismic hazard assessment and prediction
DE: 7230 Seismicity and seismotectonics
DE: 7260 Theory and modeling
DE: 7200 SEISMOLOGY
DE: 7205 Continental crust (1242)
SC: Seismology [S]
MN: 2004 AGU Fall Meeting