Document Type : Original Research Article
Institute of Geophysics, Department of Seismology, University of Tehran, Tehran, Iran
Department of Geophysics, Tehran North Branch, Islamic Azad University, Tehran, Iran
The Empirical Green Function and the Stochastic Finite-Fault Simulation were applied to estimate source parameters and rupture process of the November 12, 2017, earthquake with a moment magnitude of 7.3 in Ezgeleh, Kermanshah, Iran. The Ezgeleh earthquake was one of the most destructive and complex events that have occurred in this region; it seems several parallel faults have been activated. We determined the focal mechanism of the main event using first motion polarities. The result shows reverse faulting with a small strike-slip component. Also, the size of the asperity in this earthquake was estimated to be about 55km in the strike direction and 25km in the dip direction. To simulate this event, corner frequency, seismic moment, stress drop, duration, and the causative fault plane model were estimated. The simulated strong ground motions in comparison with the observed ones show good agreement; the result shows that the applied rupture model for this earthquake and the synthesizing methods are effective at simulating near-source ground motions in a broad-frequency range of engineering interest. Moreover, these approaches are successful and efficient in predicting the strong motions in the Zagros fold and thrust belt. This earthquake shows us that in areas with tectonics and seismic behavior similar to those of the Zagros fold and thrust belt, the possibility of such earthquakes is not unexpected. Therefore, it is necessary to simulate probable large earthquakes for the high safety design of these areas.