Probabilistic Assessment of PGA and UHS for Bojnurd city, the Capital of North Khorasan Province, Iran

Probabilistic seismic hazard assessment (PSHA) of horizontal peak ground acceleration (PGA) and Uniform Hazard Spectra (UHS) on bedrock for different hazard levels is conducted in this study for Bojnurd city, the capital of North Khorasan province, Iran. Therefore, all historical and instrumental earthquakes in a radius of ۲۰۰ km of the center of Bojnurd city are gathered and after elimination of the aftershocks and foreshocks, the main earthquakes are identified in order to calculate the seismic parameters by Kijko (۲۰۰۰) method. The seismotectonic model of the considered region and the seismic sources of the region have been modeled. Bojnurd city and its vicinity are meshed by ۸ vertical and ۱۱ horizontal lines. PGAs and UHS are calculated for all ۸۸ points of the mesh using the logic tree method and different attenuation relationships with different weighted coefficients. These calculations are performed for two hazard levels of ۱۰% and ۲% probability of being exceeded in ۵۰ years (hazard levels ۱ and ۲ respectively). Regional seismic hazard maps for PGAs and UHS for different locations of Bojnurd city and its vicinity are provided.

Keywords:

Probabilistic Seismic Hazard Assessment , Seismicity Parameters , Peak Ground Acceleration , Uniform Hazard Spectra , Bojnurd , Iran