Aftershocks investigation of 2010 Dec. and 2011 Jan. Rigan earthquakes in the southern Kerman province, SE Iran

A doublet of earthquakes with magnitudes of 6.5 and 6.2 in MW scale (Global CMT) on 2010 December 20 and 2011 January 27 respectively struck the area that lies between the Nehbandan and Jiroft fault systems, southeast of Iran. These earthquakes occurred in correspondence of the southwestern termination of the Kahourak right lateral strike slip fault. The focal mechanisms of both the mainshocks and the strongest aftershocks processed with first P motion method confirm the geological observations. They indicate steep dipping coseismic faults for both events, and dominant right lateral and left lateral strike slip motions, if the NE-SW and NW-SE planes are assumed as the active planes for the 2010 and 2011 earthquakes, respectively. A seismogenic zone thickness of 19 km was computed using the relationships between earthquake parameters.