Shale gas company Cuadrilla has recorded the largest tremor to date at its Lancashire fracking site.
With a magnitude of 2.1, it followed a 1.55 tremor on Thursday that forced the gas exploration site to pause operations.
Cuadrilla, whose Lancashire site is based on Preston New Road near Blackpool, confirmed that micro seismicity had been detected by its monitoring system just after 11pm on Saturday.
The company said the earthquake lasted about a second and that hydraulic fracturing was not taking place at the time.
“All the relevant regulators have been informed and we have verified that the well integrity is unaffected,” Cuadrilla said, adding that ground movements of this level were to be expected. “Whilst this event has been felt by people on our site and some local households, it is well below anything that can cause harm or damage to anyone or their property.”
Cuadrilla started fracking at Preston New Road last year, but its work was interrupted on a number of occasions. The biggest tremor recorded at that time was magnitude 1.5, according to the British Geological Survey.
The disruptions last year meant the private equity-backed company was only able to partially frack one well but this month it started work on a second as it tries to gather more data to persuade policymakers and regulators that the rules governing seismic events should be loosened.
Stephen Hicks, a seismologist at Imperial College London, tweeted that the 2.1 magnitude tremor “is the largest induced event so far during the 2018-2019 hydraulic fracture operations at the Preston New Road site. It is close in size to the M2.3 earthquake in 2011 at the Preese Hall site which resulted in the suspension of fracking in the UK for seven years”.
Following the 2.3 magnitude tremor at the Preese Hall site, also near Blackpool and no longer in operation, the UK government launched a review of fracking and seismic events.
Tony Bosworth, a Friends of the Earth campaigner, said: “We don’t have to wait for yet more evidence to show that the industry can’t frack without triggering earthquakes.”
He added that the key point in opposing fracking remains that “it isn’t part of the future if the government wants to avoid climate breakdown. It’s now time for this industry to end and Whitehall needs to instead back renewable energy and energy saving.”
Cuadrilla has said that the Preston New Road exploration site is the most regulated and monitored site in Europe and the systems in place are working as they should.
Fracking supporters in the UK, which also include the energy and petrochemicals giant Ineos, were given renewed hope last week that the rules on seismic events — known as the “traffic light system” — could be revised when the department run by the new business and energy secretary, Andrea Leadsom, opened the door to a possible review.