An earthquake with a magnitude of 2.9 has been recorded near the UK’s only active shale gas site in Lancashire.
The tremor near Blackpool was recorded at about 08:30 BST and is stronger than those that forced Cuadrilla to suspend test fracking in 2011.
Cuadrilla said it was investigating the tremor and said no fracking was being carried out at the time.
The Oil and Gas Authority (OGA) said fracking would be suspended while it assessed recent seismic activity.
The latest quake follows another earthquake, with a magnitude of 2.1, measured at the Little Plumpton site on Saturday.
At present, government guidelines state that if fracking induces quakes above 0.5 magnitude then all drilling must cease for 18 hours.
However, the OGA said the current suspension would potentially remain in place longer, allowing it to consider carefully whether Cuadrilla’s fracking plans “continued to be appropriate to manage the risk” of increased seismic activity at the Preston New Road site.
Drilling was previously suspended in 2011 after earthquakes of 1.4 and 2.3 magnitude hit the area.
It resumed last October after campaigners failed to get an injunction. The recent earthquakes are the largest recorded since operations resumed.
People living nearby reported feeling the tremor.
Samantha Wheeler, who lives five miles away in Lytham St Anne’s, said her “wardrobe shook and her bed moved” when she felt the earthquake.
She said: “It’s getting really worrying.”
Heather Goodwin, who also lives in Lytham St Anne’s, said: “The walls of my house shook, there was a really deep, guttural roar. For a moment, I really thought my house was going to fall down.
“It only lasted a few seconds but I felt the need to go all round the house and check for damage. We’ve been afraid of this happening. How long before there’s real damage done and people injured?”
‘Doors may rattle’
Dr Ben Edwards, reader in seismology at the University of Liverpool, said vibrations from this latest tremor were likely to be “frightening” to people.
“Windows, doors and dishes may rattle. The shaking itself will likely last less than a second and may be accompanied by sound,” he said, which could sound like a “car crashing” or “very loud bang”.
Dr Edwards said a tremor of 2.9 would not cause structural damage but the increase in magnitude of each recorded seismic activity at the fracking site recently was “a concern”.
‘Concern for people’
The regulator would want to be assured the magnitude would not increase further, with cosmetic damage previously reported from tremors of 3.5, he added.
Cuadrilla said it appreciated the tremor had “caused concern for local people” and said “it is worth noting that this event lasted for around a second and the average ground motion recorded was 5mm per second”.
“This is about a third of that permitted for construction projects,” it added.
It said the shale gas well was intact and it was working with regulators.
However, environmental campaign group Friends of the Earth has called for a complete fracking ban after three of the latest tremors.
‘Out of hand’
Spokesman Jamie Peters said it was “getting out of hand”.
“It’s clearly not under control and at this point there is only one thing that can fix this situation: a ban, right now.”
Fracking is the process of fracturing rocks with a high pressure mixture of water and chemicals to extract shale gas.
It has long been seen by the UK government as an important potential energy source.
However, the process of extracting unconventional gas in the UK has brought a flurry of protests and legal challenges.
What is fracking?
- Hydraulic fracturing, or fracking, is a technique to extract gas and oil from the earth
- Liquid is pumped underground at high pressure to fracture shale rock and release gas or oil within
- Applications have also been submitted by various firms in Yorkshire, Nottinghamshire and for a second site in Lancashire
- The Department for Business, Energy & Industrial Strategy says shale gas “has the potential to be a new domestic energy source”