Source Characteristics of the 2012 Ahar-Varzaghan Earthquake

Abstract

The August 11, 2012 M w 6.4 earthquakes in northwestern Iran occurred as a result of oblique strike-slip faulting in the shallow crust of the Eurasia plate, approximately 300 kilometer east of the plate boundary between the Eurasia and Arabia plates. The seismotectonics of this region is controlled by the collision of the Arabia and Eurasia plates; at the latitude of the earthquakes, the Arabia plate moves almost due north with respect to the Eurasia plate at a rate of approximately 26 millimeter per year. Over the past forty years, seven earthquakes of M w 6 or greater have occurred within 300 kilometer of today’s events. The nearest was a M w 6.1 earthquake in February of 1997, approximately 100 kilometer to the east, which caused 1100 fatalities. The studied area encourage the authors to determine the focal mechanism, source time function and sub events’ features which can guide us to reliable judges.