Awaran,Pakistan,earthquake of Mw 7.7 in makran accretionary zone,24 september 2013: Preliminary seismotectonic investigations

A large part of balochistan in southwest pakistan was devastated by an earthquake of magnitude mw 7.7 and focal depth of 10 km on 24 september,2013. located in the makran accretionary zone,the awaran earthquake was followed by a major aftershock of mw 7.2 that occurred 90 km nne of awaran on 28 september,2013. the earthquake caused widespread destruction in the remote and poorly accessible area,with death toll exceeding 825. an intensity of iix on mmi scale is assigned to the epicenter of the main shock using the information from the print and electronic media and some field studies. the damage to property and loss of lives occurred due to non-engineered construction of structures within 100 km of the main shock. fault-plane solutions of both the main event and its largest aftershock,and the distribution of aftershocks suggest that the nne-ssw-trending left-lateral strike-slip awaran fault is currently active. this is also supported by the analysis of more aftershocks fault-plane solutions. the formation of a mud volcano is the probable cause of the emergence of a 200 x 100 m island off the coast of gawadar a few hours after the main shock. on the one hand,this event has released high seismic energy in ne-sw direction along the chaman fault zone and makran subduction zone,and on the other it has increased the tectonic stresses in the northern and se directions,which may cause higher seismicity in future. © pakistan academy of sciences.