Case study and lessons learnt from October 08, 2005 Pakistan Earthquake

M. Nawaz Chaudhry 1, Syed Shahid Hussain 2, Iftikhar Hussain Baloch 1,
Hamid Dawood 2 and Naveed Ahsan 1

1College of Earth & Environmental Sciences, University of the Punjab, Lahore, Pakistan
2Pakistan Museum of Natural History, Garden Avenue, Shakar Parian, Islamabad, Pakistan

The October 08, 2005 Pakistan Earthquake, which struck the Kashmir-Hazara mountainous region of NE Pakistan had a magnitude of 7.6 on Richter scale. It had a hypocenter at a depth of 15 to 25 km, with epicenter about 12 km NNE of Muzaffarabad, the capital of Azad Jammu and Kashmir. The earthquake occurred, on the face of it, due to approximately 70 km long rupture zone with discontinuous SW verging brittle deformed imbricate zone along the Kashmir Boundary Thrust part of which was earlier mapped as Muzaffarabad fault. The high relief area affected by the earthquake is particularly susceptible to mass movement due to its location in and close to the Himalayan Syntaxial Bend that hosts a large number of faults including Main Boundary Thrust, a major Himalayan megashear, and the active, Indus Kohistan Seismic Zone (IKSZ) which has presumably not day lighted yet. About 85,000 people were killed while almost a million people were displaced.                 

The heavy loss of life and property can be attributed to improper building structures due to absence of building codes and abandoning of traditional wooden structures for cobble-lean cement walls with heavy and often reinforced concrete roof lanter structures, structures built on unstable slopes, and mass movements. While loss of life can also be attributed to failure of rescue efforts due to lack of a rescue agency, lack of rescue plans, destruction of infrastructure including communication network, shortage of helicopters and almost total collapse, due to heavy casualties, of administrative and political structure. Although rescue efforts were poor, mitigation was quick, massive and quite successful due to immediate response by people of Pakistan, establishment, political and Non-Government organizations, followed a little later by generous international response.

The rehabilitation efforts are also going very well and on scientific lines involving an expenditure of approximately five billion dollars on the part of the Government of Pakistan. The supervised construction activity is based on proper building codes taking into account seismicity, slope stability and foundation design. Considering the survival of framework structures and some structures built to stand up to earthquakes of about 7.5 on Richter scale, it is estimated that, after rehabilitation, causalities and loss of property will be radically reduced in any future earthquake like the one of October 8.