HR: 09:45h
AN: S51C-08 [Abstracts]
TI: Dynamic Models of Earthquakes and Tsunamis
AU: * Wendt, J
EM: James.Wendt@pomona.edu
AF: Department of Physics, Pomona College, 610 N. College Ave, Claremont, CA 91711,
United States
AU: Oglesby, D D
EM: david.oglesby@ucr.edu
AF: Department of Earth Sciences, University of California, Riverside, Riverside, CA 92521,
United States
AU: Geist, E L
EM: egeist@usgs.gov
AF: United States Geological Survey, 345 Middlefield Rd, Menlo Park, CA 94025, United States
AB:
The abundance of inhabited cities lining the coasts of earthquake-prone regions serves as a motivation to
investigate the effects of fault dynamics on tsunami generation. In particular, time dependent tsunami sources
are important when investigating tsunami run-up in the near-field. While typical tsunami codes use a simple
dislocation model with constant slip as a source, we link a fully dynamic earthquake model to tsunami
generation. We construct a finite element model of a fault system based on the splay fault geometry inferred to
exist in the Nankai subduction zone off of Japan (Cummins & Kaneda, 2000), and link the results to a finite-
difference depth-averaged tsunami propagation code. We find that a simple regional stress field in the splay
geometry is improbable since it is nearly impossible to produce a self-consistent model of an earthquake under
such a condition. We also find that whether the earthquake ruptures the upper splay in addition to or instead of
the main subduction fault depends upon the presence or absence of barriers along the main fault plane. The
tsunamis resulting from these two different rupture patterns differ strongly, emphasizing the effect of fault
geometry on tsunami generation and near-source run-up.
DE: 4564 Tsunamis and storm surges
DE: 7209 Earthquake dynamics (1242)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7290 Computational seismology
SC: Seismology [S]
MN: 2007 Fall Meeting