News

Old fault zone could be to blame for earthquake

(27 February 2008)

An old fault zone could be to blame for the earthquake that shook the UK early today, according to a Durham University expert.

The fault zone has possibly lain dormant for hundreds of millions years. Professor Robert Holdsworth, expert in structural geology, said: “Most potentially damaging earthquakes like this occur near to plate boundaries such as the San Andreas Fault. The UK, however, lies in the interior of a plate so this is quite unusual. “Although the causes and controls of UK seismicity are still poorly understood, it is possible that this earthquake reflects the reactivation of an old fault zone that has lain dormant for tens or hundreds of millions of years. “The UK crust is riddled with such old faults which form an important part of our geological heritage. Perhaps this one is just reminding us that it is still there.” Professor of geophysics at Durham University, Roger Searle, also commented on the event. He said: “Although most earthquakes occur along tectonic plate boundaries such as the San Andreas Fault, Britain does experience a moderate level of seismic activity. “This reflects minor adjustments to the stresses that occur in all plates. “A ‘quake as large as the Market Rason quake is quite rare in Britain: It is almost 25 years since the last one of this size, which was in Wales. Enormous earthquakes like the 2004 Banda Aceh Boxing Day earthquake are about a million times more energetic than this one.“