2012 East Azerbaijan Earthquakes
Tectonic setting
Iran lies within the complex zone of continental collision between the Arabian plate and the Eurasian plate, which extends from the Bitlis-Zagros belt in the south to the Greater Caucasus Mountains, the Absheron-Balkan Sill and the Kopet Dag mountains in the north. The collision between these plates deforms an area of ~ 3,000,000 km of continental crust. It is one of the largest convergent deformation regions on Earth. In northwestern Iran, the Arabian plate is moving northwards at about 20 mm per year relative to the Eurasian plate, somewhat oblique to the plate boundary zone. The deformation in the area near Tabriz is dominated by the North Tabriz Fault, a WNW-ESE trending right-lateral strike-slip fault, which has been responsible for 7 historical earthquakes of magnitude greater than 6 since AD 858. Other known active faults include a W-E trending fault between the cities of Ahar and Heris.
Earthquakes
The 6.4 and 6.2 intraplate earthquakes occurred as a result of oblique strike-slip faulting in the shallow crust about 300 km east of the Eurasia-Arabian plate boundary. The two earthquakes are separated by 10 km in an east–west direction.
Damage and casualties
Iran's state television reported the earthquake hit near the towns of Ahar, Heris and Varzaqan in East Azerbaijan province at 4:53 p.m. local time (12:23 GMT). "268 people, 219 women and 49 men, lost their lives in hospitals" while the rest were killed on the spot, Iran's Health Minister Marzieh Vahid-Dastjerdi said. The Iranian minister added that 3,037 people have been injured as a result of Saturday's temblors. According to the head of Iran's Rescue and Relief Organisation, access to villages has been cut and the only communication is via radio. The worst damage and most casualties were in villages near the towns of Ahar, Varzaghan and Heris. In villages near Varzaqan, with most men away from home working, the many mud brick houses which collapsed trapped mainly women and children inside.
Sixty-six rescue teams were sent to the affected region, along with about 200 ambulances and five helicopters. One hundred and thirty villages were 70–90 percent destroyed, and 20 were completely leveled. At least 45 people died and more than 500 were injured in Ahar, where electricity and phone lines were cut after the earthquakes. More than 40 people died in the city of Varzaqan and 50 were killed in Heris. The medical infrastructure in the catastrophe stricken region is not sufficient, and many heavily injured did not survive the rather long way to the nearest hospital.
Most parts of Tabriz also lost electricity, and the city had a large traffic jam. Some buildings were structurally damaged. Over 200 people in Varzaqan and Ahar were extricated from under the debris of collapsed buildings, and local provincial officials asked people in the region to stay outdoors during the night because of the danger of aftershocks. Some residents needed bread, tents and drinking water.
