HR: 0800h
AN: G11A-0763 [Abstracts]
TI: Co-Seismic Gravity Modeling of a Fault Network in Southern California
AU: * Hayes, T
EM: thayes@uwo.ca
AF: The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7
Canada
AU: Tiampo, K
EM: ktiampo@uwo.ca
AF: The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7
Canada
AU: Rundle, J
EM: rundle@physics.ucdavis.edu
AF: Center for Computational Science and Engineering, University of California, Davis, CA 95616
United States
AB:
The mitigation of seismic hazards within the highly populated area of Southern California is a
difficult problem which is dependent upon such observational parameters as plate motion and strain
accumulation. It has been suggested [\textit{Okubo}, 1992] that one can use Bouguer anomalies as a
proxy for permanent strain deformation at depth. To date, there are no large-scale models that
successfully model the temporal gravity signal over extended spatial regions encompassing a network
of faults, such as that which exists in Southern California. We present here a computational model
for the temporal evolution ofcoseismic gravity changes based on the analytical solutions of
\textit{Okada} [1985]and \textit{Okubo} [1992], as inferred through the slip histories (both
aseismic and unstable) generated by the general earthquake model simulations of the
southernCalifornia fault network [\textit{Rundle} 1988]. These long-period gravity signals are well
within the range of land based observations. Currently, several remote sensing satellites designed
specifically for gravity data collection (e.g. GRACE, CHAMP, GEOS) are ideal candidates for the
observation of these signals once the integration times of the data collection are long enough to
produce the required resolution [\textit{Sun and Okubo}, 2004]. This technique should be applicable
to any mechanism in which deformation occurs such as volcanic activity or glacial rebound.
DE: 8122 Dynamics, gravity and tectonics
DE: 7205 Continental crust (1242)
DE: 1242 Seismic deformations (7205)
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting