A tremor measuring 2.1 on the Richter scale has been recorded at the UK’s only active fracking site – the largest ever detected at the facility.
Energy firm Cuadrilla said the “micro seismic event” at its site near Blackpool was detected at 11.01pm on Saturday.
It came just days after the previous record was set at the Preston New Road facility last Wednesday, when a 1.55-magnitude tremor was recorded.
The company said Saturday’s tremor lasted for about one second and occurred when no fracking was taking place.
While some local residents may have felt the movement, it was not strong enough to have caused any damage to property, the firm added.
“We can confirm that a micro seismic event measuring 2.1ML (local magnitude) on the Richter scale occurred at Preston New Road,” a spokeswoman said.
“This lasted for around one second and resulted in ground motion less than 1.5 mm/s. Hydraulic fracturing was not taking place at the time.”
According to the British Geological Survey, the tremor had a depth of 2km (1.2 miles) and was felt by residents in areas including Great Plumpton, Blackpool and Lytham St Annes.
Regulators were informed and the “integrity” of the well has been confirmed, Cuadrilla said.
Stephen Hicks, seismologist at Imperial College London, said the movement was almost as strong as a 2.3-magnitude tremor at Cuadrilla’s Preese Hall site in 2011, which led to the suspension of fracking in the UK for seven years.
He tweeted: “M2.1 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 7 years.”
Fracking was temporarily stopped at Preston New Road after Wednesday’s tremor, which Cuadrilla said would have felt similar to someone dropping a large bag of shopping on the floor.
Pausing work for 18 hours is the routine response for any tremor over 0.5.
Labour’s shadow business secretary Rebecca Long Bailey has called for fracking to be banned, saying it causes air and water pollution and contributes to climate change.
Environmental campaign group Friends of the Earth said in 60 days of fracking last year there were 57 tremors in Lancashire and that it cannot be carried out without triggering earthquakes.
“Even small vibrations at ground level can be the sign of far more damaging impacts deep underground,” said Jamie Peters, a campaigner for the organisation.
The Government has said the extraction of shale gas through fracking could support the UK’s transition to net zero greenhouse gas emissions.