SURREY has been rocked by a 2.7 magnitude earthquake today - the second in just 12 hours.

The quake was the sixth to shake the area near both Gatwick and Heathrow airports in just four weeks - and raised the unlikely spectre of a 'Big One' hitting London.

5 A tremor was recorded this morning, with seismologists seeing a spike just after 1.30pm Credit: Twitter

Dr Stephen Hicks installs seismic monitoring station in Surrey after series of earthquakes

Previous quakes have included a 2.6 magnitude tremor felt in parts of Surrey and West Sussex on June 27 and a quake measuring 2.6 recorded on June 30.

Today's 2.7 tremor was recorded at Newdigate, which is eight miles from Gatwick and 30 miles from Heathrow, just after 1.30pm.

It was less than a mile below the surface.

Just hours earlier, a tremor was recorded at 4.59am at Newdigate at a magnitude of 2.0.

Large earthquakes are extremely rare in Britain but scientists recently uncovered two fault lines running directly under London.

SEISMIC ALERT: NEWDIGATE,SURREY 18 JULY 2018 13:33 UTC 2.7 ML — British Geological Survey (@BritGeoSurvey) July 18, 2018

5 The quake was recorded just after 1.30pm today

5 Newdigate was hit with two small tremors in less than 12 hours Credit: Alamy

5 An aerial image shows the Ibstock Brick quarry at Newdigate, Surrey Credit: Alamy

5 Another tremor was felt in the early hours of this morning in the same area Credit: Twitter

It comes as fears a big earthquake could hit after scientists discovered two fault lines running under London.

Researchers claimed the shaking would be similar to standing on a platform between two passing trains.

Dr Richard Ghail, a specialist in civil and environmental engineering at Imperial College told the Telegraph the chance of a quake is "enough to be scary, but not fundamentally a problem".

He claimed the biggest issue is not the earthquake itself but the impacts because of the city's "complicated" infrastructure.

The two faults move around 1mm to 2mm a year, with one running directly under central London and the other under Canary Wharf.