Physics-Based Earthquake Simulations of the
Anninghe-Zemuhe-Daliangshan-Xiaojiang Fault system in the Southwestern
China
Abstract
Seismic hazard evaluation is important for urban construction,
earthquake disaster prevention and mitigation. However, because of the
long recurrence times of large earthquakes (hundreds to thousands of
years), seismic hazard assessment based on relatively short-term (tens
of years) observational seismic catalog is difficult. Synthetic seismic
catalogs provide a useful way to obtain long-term seismic hazard. Based
on Coulomb failure criterion, we apply a quasi-static physics-based
earthquake simulator (Virtual Quake) in a tectonically complicated
region with several major faults, namely the Anninghe, Zemuhe,
Daliangshan and Xiaojiang faults, in the Southwestern China. Slip rates
of those major faults are constrained by the GPS data, and frictions are
constrained by the laboratory experiments. Considering the stress
interactions among the fault system, a synthetic catalog over 20, 000
years is simulated. The simulated catalog shows consistence with the
observed seismicity in spatial distribution of large earthquakes, b
value and mean seismic rate. The synthetic catalog also shows that the
mean intervals of M≥7.0 earthquakes for the Anninghe, Zemuhe,
Daliangshan and Xiaojiang faults are 299a, 867a, 361a and 90a,
respectively. Our results provide a helpful index to evaluate seismic
hazard in such a complicated region.