The UK’s only fracking site has been hit by a second earthquake, days after the largest ever recorded, accorded to the energy firm Cuadrilla.
The fracking site at Preston New Road in Lancashire experienced a tremor measuring 1.05 on the Richter scale on Friday night, two days after a magnitude 1.55 tremor.
The company said the “micro seismicity” lasted for less than one second and said the overall “integrity” of the well was fine. A smaller 0.53 magnitude tremor occurred just after 5am on Saturday and also lasted for less than one second, the company added.
Pausing work for 18 hours is the routine response for any tremor over 0.5.
The shutdown came less than one week after the energy firm started fracking a new well on the site after closing down the first one following a string of tremors.
A Cuadrilla spokesman said on Thursday that most people who live near the Preston New Road facility would not have noticed Wednesday’s movement, which would have felt similar to someone dropping a large bag of shopping on the floor.
“Minor movements of this level are to be expected and are way below anything that can cause harm or damage to anyone or their property,” he said.
While smaller quakes are not generally felt at the surface, there are concerns repeated events will cause damage to infrastructure, and that they could lead to large tremors that compromise the fracking borehole and cause leaks.
Fracking, in which liquid is pumped at high pressure deep underground to fracture rock and release gas, has proved controversial in the UK.
Backers, including the government, claim exploiting the fossil fuel could reduce reliance on imports, secure supplies, help cut carbon emissions and create jobs.
But opponents say fracking can cause earthquakes, damage the countryside and keep the UK hooked on fossil fuels instead of focusing on renewable energy to help tackle climate change.
Green groups say investing in further gas extraction will go against the warnings by climate scientists that fossil fuels must be eliminated as soon as possible.
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.
"The event lasted for less than one second and the measured vibration at ground level during the event was approximately 0.4 mm/s," Cuadrilla said in a statement after the latest tremor. "This micro seismicity followed today’s pumping operations. The integrity of the well has been confirmed."