Surrey earthquakes: Another two tremors strike county as mysterious 'swarm' continues

Two earthquakes have been recorded in Surrey in the space of just 10 hours, becoming the latest in a series of mysterious tremors to hit the southern county since April.

The first struck Newdigate, near Dorking, at around 4am on Wednesday, and was measured a 1.7 magnitude at a depth of up to 700m.

At 1.33pm, the British Geological Survey (BGS) recorded another, bigger, quake in a similar area, measuring 2-3 magnitude.

One local said they heard the initial tremor as a “weak thud” and that their house “shook for a second or two”.

They are thought to be the ninth and 10th earthquakes to have struck Surrey in recent months. The first was felt on 1 April, with many more occurring throughout June and July.

Tremors have been felt in Newdigate, Dorking, Horley and Charlwood in Surrey, and also Crawley and Horsham in West Sussex.

But experts still have no idea what is behind them. As seismologists scratch their heads, this “swarm” of earthquakes has flared tensions between oil companies intent on drilling the countryside and locals concerned the activity is destabilising the very land they live on

Residents were quick to make the link between the earthquake epicentres and the close proximity of oil drilling operations.

As far as scientists are concerned, however, the jury is out. While they suspect there is nothing suspicious about the earthquakes striking the southeast, there is also not enough evidence to conclude whether they are natural or man-made.

“We hope to gain a better understanding of this scientific phenomena through the installation of additional stations,” said a BGS spokesperson.

“We are unable to say categorically if these earthquakes are related to hydrocarbon exploration or production, mainly because of the uncertainties in our estimates of the earthquake epicentres and particularly depths.”