HR: 0800h
AN: T41F-1286    [Abstracts]
TI: Spatial Localization of Moment Deficits in Southern California
AU: * Meade, B J
EM: meade@fas.harvard.edu
AF: Harvard University, Department of Earth and Planetary Sciences 20 Oxford St., Cambridge, MA 02138
AU: Hager, B H
EM: brad@chandler.mit.edu
AF: Massachusetts Institute of Technology, Department of Earth, Atmospheric and Planetary Sciences 77 Massachusetts Ave., Cambridge, MA 02139
AB: The balance between interseismic elastic strain accumulation and coseismic release defines the extent to which a fault system exhibits a surplus or deficit of large earthquakes. We calculate the regional moment accumulation rate in Southern California based on a slip rate catalog estimated from a block model of interseismic deformation constrained by GPS measurements. The scalar moment accumulation rate, $17.8 \pm 4.6 \times 10^{18}$ Nm/yr, is approximately $50%$ larger than the average moment release rate over the last 200 years. Differences between the accumulated and released elastic displacement fields are consistent with moment deficits that are localized in three regions: the southern San Andreas and San Jacinto faults, offshore faults and the Los Angeles and Ventura basins, and the Eastern California shear zone. The moment budget could be balanced by coseismic events with a composite magnitude of M_W=8.
DE: 7223 Seismic hazard assessment and prediction
DE: 8123 Dynamics, seismotectonics
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting