Earthquake Hazard Zonation and Seismotectonics of the Bandar Abbas Area, Zagros, Iran

Abstract

The study area (Bandar Abbas area) is located in the Zagros fold-thrust belt as part of the Alpine-Himalayan orogenic belt as seismically active belt. This area is located between the Makran accretionary prism and Oman Mountains from east and the Zagros collision belt from west as transition zone. The Zagros fold-thrust belt from the viewpoint of seismicity, is very active and Iran’s major earthquake-prone area. The study area has main active faults and some high magnitude earthquakes occurred in current century. Because the Bandar Abbas area has high seismic activity, the main goal of this research is prepared to earthquake hazard zonation and identify hazardous seismic zones, based on Decision Support System method for define active seismotectonic in this area. The seismotectonic study has been done in 30 - 100 km radius, for Bandar Abbas area. In this research, we used Decision Support System method by in corporate and combine essential data such as seismic data from 1900-2015, Digital Elevation Model of the study area (DEM), surface geology, seismicity parameters, soil classification and location main faults. In this research the Decision Support System (DSS) base on GIS database is used for calculate seismicity parameters. Based on the relative risk of earthquake zonation map, the Bandar Abbas area is located from the north to the East and from the South to the East, in area with high seismic risk (with Orange color). Some small regions with very high relative seismic risk have been limited to these areas with high risk. Also from north to west and from south to west “the study area” is located mainly in the area with earthquake relative risk of in areas with moderate and low relative risk of earthquakes. In the far southwestern region of the study, the small area is located in an area with high and very high seismic relative risk and this case may be due to the activity of the Mountain Front Fault (MFF) and Zagros Fore deep Fault (ZFF). Finally, the study area has been affected by active faults and it causes high vulnerability of the study area in the face of a possible occurrence of earthquakes. Based on of Seismotectonic investigations, there are existed minor faults of the Zagros fault from East to West and in the middle part. This case has been caused some parts in the study area with low and moderate seismic risk to be considered in the face of possible earthquakes and seismic damages, as an area with high seismic risk.