Seismotectonic analysis of Guriyeh area with a view to the Guriyeh earthquake swarm of the years 2017-2018 (Khuzestan province)

In this research, seismotectonic analysis has been done Guriyeh area (subsidiary of Shooshtar city, Khuzestan province, Iran) with radius of 25Km. In this research, nine months of Guriyeh earthquake swarm from 2017-11-15 to 2018-7-20 has been studied. The main purpose of this study is to provied evidences to prove the activity of new seismic trends and finally, the need to strengthen historic and dilapidated buildings in this area. Seismogenic history, field evidences, epicenter locations (in the form of seismic bunch) and their migration trend toward Southwest (N30E), indicate the activity of Northeast-Southwest seismic trend in the vicinity of Northwest-Southeast seismic trend (Zagros trend) and their conformity with location of surface and subsurface faults in this region. It also expresses the focal mechanism provided for earthquakes in this region, the compression mechanism and some cases with oblique right-slip component, for faults causing seismogenic in this area. The main collected evidence indicates reactivation of Sardarabad fault, subsurface fault(UGC-FAULT) and magnetic lineament (MGL-1). To continue, seismic hazard analysis has been done using deterministic approach for this region, and maximum seismogenic power (MSmax), 7.14 in Richter scale for the subsurface fault(UGC-FAULT) and peak ground horizontal acceleration(PGA)of 0.27g for the magnetic lineament (MGL-1) were calculated.