The Application of Potential Rupture Surface Model on PSHA in the Area Near the 2008 Wenchuan Earthquake

Potential sources are simplified as point sources or linear sources in current probabilistic seismic hazard analysis (PSHA). Focus size of large earthquakes is considerable, and fault rupture attitudes may have great influence upon the seismic hazard of a site which is near the source. Using the potential rupture surface model, we analyze the seismic hazard near the Longmenshan central fault that generated the Wenchuan earthquake with magnitude 8.0 in 2008. The following conclusions are reached: (1) The seismic zoning results show hanging-wall effect, although it is not very clear because of the high dip of the causal fault, in agreement with the isoseismal lines of intensity IX or higher; (2) As far as the seismic hazard analysis result is concerned, it is more reasonable to use the potential rupture surface model in the PSHA than to use the current potential source model because it can avoid hazard dilution near the causal faults.