An earthquake shook homes in Surrey’s leafy commuter-belt overnight as residents in the county’s ‘earthquake zone’ were panicked by tremors for the third in three months.
‘Scary loud bangs’ were reported by people in the Crawley area and a seismograph from the British Geological Survey confirmed the quake happened at 1.19am.
It is the latest shudder to strike the region following Newdigate’s trembling on February 27 which was the most powerful earthquake in the south east for 50 years.
Last night, one concerned resident tweeted: ‘Did an earthquake just happen in Crawley? My whole flat just shook underneath me!’
A seismograph from the British Geological Survey shows the tremor at 1.19am BST
‘Scary loud bangs’ and ‘shakes’ were reported by people in the Crawley area overnight
Another said: ‘Just looked at the sensors around the Gatwick area on BGS’s website and it confirms we did have an earthquake at 1:19. Lasted about a second or 2 but woke me up…’
The magnitude of the tremor is not yet clear.
It follows a series of earthquakes in the Surrey area in February, when four tremors were recorded in the space of a fortnight.
Concerns were raised that the quakes were the result of nearby oil and gas exploration.
Special monitoring equipment was installed last July to better understand what is happening beneath the surface of the area, which is near Gatwick Airport
Stephen Hicks, seismologist at Imperial College London, said at the time that while scientists were ‘keeping an open mind’, there was ‘still no available evidence which points towards the triggering by man-made activities’.
He said: ‘It is most likely that these earthquakes are natural – due to small tectonic stresses occurring on old geological faults caused by stresses from our nearest plate boundaries in the Mid-Atlantic and Mediterranean.’
A 3.0-magnitude earthquake hit Newdigate, Surrey, on February 27, which followed a 2.0-magnitude tremor on February 19 and 2.4 and 0.2 quakes on February 14.
WHAT CAUSES EARTHQUAKES?
Catastrophic earthquakes are caused when two tectonic plates that are sliding in opposite directions stick and then slip suddenly.
Tectonic plates are composed of Earth’s crust and the uppermost portion of the mantle.
Below is the asthenosphere: the warm, viscous conveyor belt of rock on which tectonic plates ride.
They do not all not move in the same direction and often clash. This builds up a huge amount of pressure between the two plates.
Eventually, this pressure causes one plate to jolt either under or over the other.
This releases a huge amount of energy, creating tremors and destruction to any property or infrastructure nearby.
Severe earthquakes normally occur over fault lines where tectonic plates meet, but minor tremors – which still register on the Richter sale – can happen in the middle of these plates.
The Earth has fifteen tectonic plates (pictured) that together have molded the shape of the landscape we see around us today
These are called intraplate earthquakes.
These remain widely misunderstood but are believed to occur along minor faults on the plate itself or when ancient faults or rifts far below the surface reactivate.
These areas are relatively weak compared to the surrounding plate, and can easily slip and cause an earthquake.
Earthquakes are detected by tracking the size, or magnitude, and intensity of the shock waves they produce, known as seismic waves.
The magnitude of an earthquake differs from its intensity.
The magnitude of an earthquake refers to the measurement of energy released where the earthquake originated.
Earthquakes originate below the surface of the earth in a region called the hypocenter.
During an earthquake, one part of a seismograph remains stationary and one part moves with the earth’s surface.
The earthquake is then measured by the difference in the positions of the still and moving parts of the seismograph.