The 2008 Ziarat earthquake hit the Pakistani province of Balochistan on October 29 with a moment magnitude of 6.4. The US Geological Survey reported that the quake occurred 60 km (37 mi) north of Quetta and 185 km (115 mi) southeast of the Afghanistan city of Kandahar at 04:09 local time (28 October, 23:09 UTC) at a depth of 15 km (9.3 mi), at 30.653°N, 67.323°E. It was followed by another shallower magnitude 6.4 earthquake at a depth of 10 km (6.2 mi) approximately 12 hours after the initial shock, at 30.546°N, 67.447°E. 215 people were confirmed dead. More than 200 were injured (according to Mohammed Zaman, assistant to the Balochistan chief secretary, Nasir Khosa), and 120,000 were homeless (according to Dilawar Khan Kakar, Ziarat, Balochistan mayor and chief administrator). The New York Times reported that Qamar Zaman Chaudhry, director general of Pakistan Meteorological Department, stated the quake epicenter was 70 miles (110 km) north of Quetta, and about 600 km (370 mi) southwest of Islamabad.
|Date||October 29, 2008 (October 28 UTC)|
|Depth||10 km (6.2 mi)|
Earthquakes and active faults in western and northern Pakistan and adjacent parts of Afghanistan are the result of the Indian plate moving northward at a rate of about 40 mm/yr (1.6 inches/yr) and colliding with the Eurasian plate. Along the northern edge of the Indian subcontinent, the Indian plate is subducting beneath the Eurasian plate, causing uplift that produces the highest mountain peaks in the world, including the Himalayan, the Karakoram, the Pamir and the Hindu Kush ranges. West and south of the Himalayan front, the relative motion between the two plates is oblique, which results in strike-slip, reverse-slip, and oblique-slip earthquakes. The pattern of elastic waves that were radiated by the October 28 and 29, 2008, earthquakes implies that each earthquake was the result of predominantly strike-slip faulting. Seismographically recorded waveforms imply that the shocks were caused by either left-lateral slip on a northeast-striking fault or right-lateral slip on a northwest-striking fault. The tectonic setting favours left-lateral slip on a northeast-trending fault as the likely fault plane.
The October 28 and 29 earthquakes occurred in the Sulaiman fold-and-thrust belt, a region where geologically young (Tertiary) sedimentary rocks have been folded and squeezed by forces associated with the Indian-Eurasian collision. The earthquakes are located approximately 80 km east of the 650-km-long Chaman fault, which is a major left-lateral strike-slip fault that accommodates a significant amount of the slip across the plate boundary. The occurrence of the earthquakes suggests that other left-lateral strike-slip faults are present beneath the fold-and-thrust belt and that they accommodate some of the relative motion of the Indian and Eurasian plates.
The earthquakes of October 28 and 29, 2008, are located approximately 50 km northeast of the region of most intense damage from the earthquake of May 30, 1935 (M 7.6), which is estimated to have killed 30,000 people. The 1935 earthquake probably occurred as the result of left-lateral strike-slip motion on a northeast-striking fault.
Most of the casualties were from two villages on the outskirts of Ziarat town. Balochistan chief minister Nawab Aslam Khan Raisani ordered declaration of emergency in the hospitals of the affected areas. These areas, situated on steep terrain, were badly damaged by landslides caused by the quake. Hundreds of mud houses were destroyed.
Dilawar Khan, mayor of Ziarat District, stated that his office had requested support from the local government. Pakistani military helicopters and troops were dispatched to assess damage and aid victims.