Primary report of Sirch earthquake 2011 Jun 26 Mn 5.2 (Sirch, Kerman)

Description

  Primary report of Sirch earthquake 2011 Jun 26 Mn 5.2 (Sirch, Kerman)   Shokri, M., Eskandari, M and M,. Zia Seismotectonic & Seismology department Geological survey of Iran        The Sirch earthquake of 2011 Jun 26 (MN 5.2; IRSC- MW 5.1; USGS) occurred at 19:47:01 UTC (00:17:08 local time on 6 tir 1390) in Sirch, Golbaf and Anduhjerd in Kerman Province. The instrumental epicenter of this event given by IRSC is 30.21˚N;57.63˚E; located at the 8 km NE of Sirch,  38 km NW of Golbaf city and 55 km SE of Kerman with 13 km in depth (table 1). 6 aftershocks with magnitude between 2.5-3.5 were registered by IRSC after about 5 days after  the mainshock. On the other hand, 3 foreshocks were registered before the mainshock in this area. The first occurred 10 hours before mainshock with magnitude 3.7 in MN scale at the 9 km NE of Golbaf. Second foreshock with magnitude 3 were registered 4 hours after first one at the 17 km SW of Sirch. The last one occurred 3 minutes before mainshock with magnitude 3.3 ( MN) at the 14 km NW of Golbaf.        Considering epicenter of this earthquake, it seems that Golbaf fault system caused this seismic event.  The total length of the Golbaf Fault system is about 180 km, from the southern end of the Nayband fault in the north to the Jebel-e-Barez mountains in the south. Golbaf fault system (NNW-SSE) is one part of right-lateral Nayband-Golbaf-Sabzevaran fault system which is located in west of Lut block.      Due to movement of Golbaf fault system, occurred 5 earthquakes with magnitude greater than 5, occurred in past 30 years. 1981  Jun 11 Golbaf    MW 6.6- -1981 Jul 28 Sirch        MW 7.1 1989 Nov 20 Golbaf   MW 5.8- 1998 March 14 Fandoqa MW 6.6- 1998 Nov 18 ChaharFarsakh MW 5.4- Table 1   Depth (km) Latitude Longitude Magnitude Ref. 13 30.21 57.63 Mn 5.2 IRSC 16 30.12 57.54 ML 5.1 IIEES 37.3 30.18 57.55 Mw 5.1 USGS 10 30.11 57.58 mb 4.9 EMSC IRSC: IRanian Seismological Center     IIEES: International Institute of Earthquake Engineering and Seismology USGS: U.S. Geological Survey EMSC: European-Mediterranean Seismological Center                                           Instrumental epicenters of 2011 Jun 26 Sirch earthquake (Mn 5.2)                                         Isoseismal map of 2011 Jun 26 Sirch earthquake