Seismic hazard assessment of the city of Hamedan and its vicinity, west of Iran

This article presents the results of deterministic and probabilistic seismic hazard analyses (DSHA and PSHA) of the city of Hamedan and its neighboring regions. This historical city is one of the developing cities located in the west of Iran. For this reason, the DSHA and PSHA approaches have been used for the assessment of seismic hazards and earthquake risk evaluation. To this purpose, analyses have been carried out considering the historic and instrumented earthquakes, geologic and seismotectonic parameters of the region covering a radius of 100 km, keeping Hamedan as the center. Therefore, in this research, we studied the main faults and fault zones in the study area and calculated the length and distance of faults from the center of Hamedan. In the next step, we measured the maximum credible earthquake (MCE) and peak ground acceleration (PGA) using both DSHA and PSHA approaches and utilized the various equations introduced by different researchers for this purpose. The results of DSHA approach show that the MCE-evaluated value is 7.2 Richter, which might be created by Nahavand fault activities in this region. The PGA value of 0.56 g will be obtained from Keshin fault. The results of PSHA approach show that the MCE-evaluated value is 7.6 Richter for a 0.64 probability in a 50-year period. The PGA value of 0.45 g will be obtained from Keshin fault. Seismic hazard parameters have been evaluated considering the available earthquake data using Gutenberg-Richter relationship method. The 'a' and 'b' parameters were estimated 5.53 and 0.68, respectively.