Probabilistic Seismic Hazard Assessment of Qayen, a Seismically Active Region in East of Iran

Abstract

Summary Seismic hazard assessment is almost the most common way to decrease the loss and fatalities caused by earthquakes. Occurrence of numerous strong historical earthquakes, Experiencing twin earthquakes and being vulnerable to major earthquakes has made Qayen an important target in need of seismic hazard assessment. In this paper, seismic hazard analysis is performed using probabilistic hazard assessment method in East of Iran, in a region bounded between 32 to 35 N and 57 to 60 E. First, the seismotectonic map of the region is provided using geological maps and earthquakes and micro-earthquakes catalog. Then, 8 Potential seismic sources were detected considering region’s tectonic, seismicity of the area and type of the faults. After that, seismicity parameters were evaluated. Finally, taking into account these obtained parameters and applying appropriate attenuation relation using probabilistic method, PGA from activity of sources around the site in Qayen city for return periods of 50, 100 and 475 years are evaluated and hazard assessment maps are depicted. Spectral acceleration curves for all sources of a particular return periods has a peak in approximately 0.2 seconds. The obtained risk maps obviously show more risk for potential seismic sources 5 and 4 in every 3 mentioned return periods.