Sunday, October 09, 2005

Pakistan earthquake--big one still to come

On 8th October at 3.50am UTC, a magnitude 7.6 earthquake hit northern Pakistan. Over the following day, a series of large aftershocks were recorded by the US Geological Survey. The quake epicentre is just between India and, in Kashmir. This is in the Pir Panjal Mountains near the border town of Muzaffarabad. It is 70-odd miles north of Islamabad.

In the early phase of any disaster like this, the predicted numbers of casualties can fluctuate wildly. But it has been clear since yesterday midday that this would be serious. There were reports that whole villages had been wiped out, and that large buildings had collapsed in cities. We also know that the Gujarat earthquake in India in 2001 (which was only slightly smaller in magnitude) killed 14,000 people in the final reckoning.

Scientists have said for years that earthquakes were overdue in this region. Sadly, they can't say exactly where and when they will hit. India is moving into Asia at a steady rate (about 1mm a week), and as this accumulated energy builds up it has to be released. Thus earthquakes happen at a fairly steady rate, causing earthquakes across the subcontinent... see map. And in an interview after the quake, Dr Roger Bilham of the University of Colorado warned that the quake has not been strong enough for the pent up stress to be relieved. The big one, then, is still to come. In fact, given the rapid urbanisation in India, and poor housing, geologists have been warning that the magnitude 8 earthquake expected in the next decade is likely to kill 1m people (see reference to Roger Bilham).

What everyone will start remembering soon is that earthquakes don't kill people--buildings do. In Bhuj, Gujarat, there were building codes but these were ignored. The same is likely to be true on both sides of the border this time round, despite efforts made by the Indian government made in the wake of the last disaster. Of course, both of these are poor countries, but it is going to be hard for state authorities to justify not enforcing building regulations in schools and government buildings.

More information
1. US Geological Survey--Earthquake information about Pakistan.
2. Amateur Seismic Centre--Pakistan Earthquake and guide to great earthquakes in Asia. And further information about seismicity of Pakistan.
3. Historical Himalayan Earthquakes--from the website of geologist Roger Bilham.
4. Roger Bilham, University of Colorado--a personal website by this university academic with much regional information about earthquakes as well as links to articles about the risk of global urban earthquakes, and an article about historic and future earthquakes in India.
5. For up-to-date reports on casualities visit India's disaster management ministry.