Earthquakes may be linked to drilling say experts

The tremors were recorded between April 2018 and early 2019 near Newdigate, with oil drilling taking place at Horse Hill

Researchers from the University College London (UCL) have claimed a series of more than 100 small earthquakes in Surrey could have been triggered by oil drilling.

The tremors were recorded between April 2018 and early 2019 near Newdigate, with oil drilling taking place at Horse Hill about five to 10km (three to six miles) away.

Drilling stopped at the site in October 2024, after planning permission was quashed following a legal case by campaigner Sarah Finch.

UKOG, the company behind the drilling, said seismologists from the British Geological Survey (BGS) were satisfied the earthquakes were caused by a fault in the earth.

The tremors measured between 1.34 and 3.18 magnitude.

The UCL study, published on Friday in the Geological Magazine, ran more than 1,000,000 simulations, estimating the timing of the events and volume of oil extraction, finding a rough match between the two.

Lead author Dr Matthew Fox said: "Our study suggests there is a link between the earthquakes and oil extraction at Horse Hill but we cannot rule out that this link is a coincidence.

"More work needs to be done to understand if this is cause and effect. However, our findings indicate it is plausible that oil extraction triggered the earthquakes."

The UCL team claimed extracting oil changes fluid pressure in rock, which can cause it to move.

Sarah Finch (holding flag) began her legal fight against Surrey County Council in 2019

A spokesman for UKOG said: "This is an incident that was answered and dealt with many years ago when the BGS seismologists were satisfied it was a natural event associated with movement on a deeper unassociated fault many kilometres deeper and distant from the site.

"Our focus is now on renewable energy and the storage of hydrogen in salt caverns in Dorset and East Yorkshire, fully in step with the government's Clean Power 2030 target."

Follow BBC Surrey on Facebook, on X. Send your story ideas to [e-mail] or WhatsApp us on 08081 002250.