Magnitude 6.4 Mw, 6.3 Mw Aftershocks at least 60 Number of casualties 306 | Depth 9 km (5.6 mi) Max. intensity VIII (Severe) Date 11 August 2012 | |
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Origin time 16:53:17 (UTC+04.30)17:04:35 (UTC+04.30) Similar 2003 Bam earthquake, 1990 Manjil–Rudbar earthquake, 1978 Tabas earthquake, 2013 Bushehr earthquake, 2002 Bou'in‑Zahra earthquake | ||
The 2012 East Azerbaijan earthquakes occurred near the cities of Ahar and Varzaqan in Iran's East Azerbaijan Province, on August 11, 2012, at 16:53 Iran Standard Time. The doublet were separated by eleven minutes, measured 6.4 and 6.3 on the moment magnitude scale, and occurred 60 kilometers (37 miles) from Tabriz. At least 306 people died and more than 3,000 others were injured, primarily in the rural and mountainous areas to the northeast of Tabriz (though 45 died in the city of Ahar). The shocks were felt in Armenia and Azerbaijan, though no major damage was reported.
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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 km2 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 6.3 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 quake 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. 130 villages were 70-90% 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 quakes. 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.
Rescue teams continued searching for survivors through the night, Iranian officials said they expected the death toll to rise. Between ten and twenty villages close to the epicenter were still cut off from aid and it would take some time to reach them. The Iranian government estimated at least 16,000 people spent the first night after the quakes in emergency shelters.
A day after the quakes, more than 36,000 people had been given emergency shelter, and the Iranian government had dispatched nearly 100 ambulances, 1,100 Red Crescent workers, 44,000 food packages and 5,600 tents. According to Red Crescent officials, more than 1,000 villages were affected by the disaster, and at least 5,000 people were injured. Hospitals in the region's major cities were overcrowded and struggling to cope with the large number of people waiting for treatment.
Aftershocks
At least 80 aftershocks were felt. A 5.0 quake struck three hours later and a 5.1 aftershock struck 31 km southwest of Ahar on August 12.
On August 14, three days after the initial quakes, another 5.1 aftershock struck the same area at a depth of 10 km. An even stronger 5.3 tremor occurred on August 15, approximately 34 km southwest of Ahar.
Domestic
The East Azerbaijan province governor announced two days of public mourning in the province. Mostafa Mohammad Najjar, Minister of Interior and Marzieh Vahid Dastjerdi, Minister of Health, traveled to Tabriz and Ahar. The Iranian Red Crescent did not request any international assistance.
International
In the first two days, the Iranian Red Crescent said they would not accept outside help. Three days later, the Iranian government announced it would accept foreign help.
Criticism of Iranian government and state TV's late response
The Iranian government was criticized regarding to crisis management of the earthquake. The decision to stop the search for survivors after 24 hours was based on a government assessment that all survivors had been rescued from the rubble; an unnamed local doctor disputed the likelihood of that assessment based on the remoteness of some villages. A lack of tents for the homeless was also cited by members of the Majlis. The IRIB was criticised in an editorial in the Asr-e Iran newspaper for its perceived lack of news coverage of the earthquake. In a Majlis meeting on August 13, 2012, MPs from the affected region questioned President Mahmoud Ahmadinejad for not visiting the area and for not announcing public mourning. That day, Iran then announced two days of public mourning.