News

Expert comments on major quake

(14 May 2008)

A leading earthquake expert today said that although the location of Monday’s earthquake was not surprising, it would be difficult to predict when another quake, like the one which hit China's Sichuan province, will happen again.

Dr Alexander Densmore, of the Institute of Hazard and Risk Research at Durham University, has studied the Beichuan fault which was probably responsible for Monday’s quake. He said: “In the last hundred years there hasn’t been much earthquake activity in this area. This poses a problem for forecasting large events, because we often learn something about faults by looking at patterns of smaller, more frequent earthquakes. Without that kind of activity, it’s difficult to say where the major faults are and how they might behave in a large earthquake. For this reason our study last year looked at the effect of past earthquakes on the landscape. “It’s quite rare that these very large earthquakes occur on land and it’s particularly rare that they occur in densely populated areas. This is an extraordinary event. “Along with the shaking and the direct effects of any surface rupture, the major threat posed by earthquakes in mountainous regions such as this one is landslides. The valleys in this area are up to 3-4 km deep and the slopes are composed of fractured, weak rock, so landslides and rockfalls are extremely common. Landslides pose a significant hazard that extends well beyond the area affected by seismic shaking. The heavy rain that has fallen in the area since Monday will only make the situation worse. “We don’t yet know the extent of landsliding due to Monday’s earthquake, but similar events are likely to occur.”