Strike-slip movements and associated structures of Shazand fault

The region of Khersan 1-5 dam is in Chaharmahal-Bakhtiari province. It is located 45 km west of Lordegan city.The reported earthquakes in this region are low depth type and have a focal depth less than 15 km. They also have no surface failure. The seismic hazard analysis illustrates the nature of seismicity of the site and is evaluated according to dispersion, fault type, morphology of faults, and past earthquakes data. Here, using tectonic maps of the site, arial and satellites photos, and the seismic data of the site, it have been tried that the seismicity of the site to be determined. Bazoft and Massan faults with 45 and 36 km length are the nearest faults to the site. When they become active, they can provide an earth quake as big as M=7.0 and 6.9 Richters,respectively. Bazoft and Massan faults have the ability to provide the MCLs as big as 0.269g, 0.222g,respectively.According to probabilistic seismic hazard analysis in the site, for return periods of 150, 475 and 2000 years, and according to Bender & Perkins (1987) method, and using (Seisrisk III) software, accelerations equal to 0.261g, 0.291g, and 0.310g, for the center of zone, are calculated respectively.