Seismotectonic and seismicity analysis of the Damghan region, Iran

Abstract

This paper deals with seismotectonic and seismicity analysis of the Damghan region, the central part of Semnan province, northeast of Iran. Seismotectonic and seismicity maps s well as active faults of the region were introduced and an earthquake catalogue of the studied area (up to 150 km radiuses) was prepared. This study addresses the main historical and instrumental earthquakes and their causative faults. Available seismic data were normalized by means of the time normalization technique that resulted in evaluating the magnitude-frequency relationship and estimating the return period of earthquakes of different magnitudes. Some active faults present in the region namely Damghan fault, north-Damghan fault, Atari fault and Astaneh fault are sources of earthquakes. Finally, the constructions were analyzed and classified and the vulnerability of the various types of structures was studied.