A fault source-based algorithm for probabilistic analysis of seismic hazard incorporating the rupture scale of large earthquakes

In this study, a seismic hazard algorithm was developed, coupled with a multi-source model. The algorithm can calculate the seismic hazard of 2D planar sources and 3D fault sources. A point source model is used to calculate the 2D planar potential seismic source by discretizing the potential seismic source into grid points which represent seismic sources. In contrast, a rupture surface model is used to calculate the 3D fault source so as to account for the influence of rupture scale in large earthquakes. The corresponding computational software was developed in Java and was tested on a study area 39.2°N–40.4°N and 116.6°E–118.7°E; the Tangshan and Xiadian faults were used to construct the fault source. Compared with the hazard results obtained using a point source model to calculate a 2D planar potential seismic source, the hazard results will be higher when a rupture surface model is used to calculate a 3D fault source. Moreover, a lower exceedance probability corresponds to a greater contribution rate of the fault source to the hazard and a greater seismic hazard closer to the fault. The algorithm can be used for seismic hazard analysis and can serve as a reference for the development of next-generation methods for zoning areas based on seismic ground motion.