A company is working with the British Geological Survey to see if there is a link between a “shale” gas drilling project and a small earthquake in Lancashire.
Cuadrilla has halted work at its site near Blackpool after the 1.5 magnitude quake last Friday. The project sees the company inject high-pressured bursts of water underground to fracture rock in a process called “fracking”.
The British Geological Survey (BGS) said the epicentre of the earthquake was within 2km of the site.
It follows a 2.3 magnitude earthquake at the beginning of last month, which also occurred near to the drilling site at Preese Hall.
The BGS said it could not say conclusively if the first earthquake, on April 1, was linked to the fracking for shale gas but the organisation’s website stated: “Any process that injects pressurised water into rocks at depth will cause the rock to fracture and possibly produce earthquakes.
“It is well known that injection of water or other fluids during the oil extraction and geothermal engineering, such as shale gas, processes can result in earthquake activity.”
Today, BGS head of seismology Brian Baptie said the survey recorded the magnitude 1.5 earthquake shortly after midnight on Friday.
He said: “Data from two temporary instruments close to the drill site, installed after the magnitude 2.3 earthquake on April 1, indicate that the event occurred at a depth of approximately 2km.
“The recorded waveforms are very similar to those from the magnitude 2.3 event last month, which suggests that the two events share a similar location and mechanism.”
The shale gas exploration scheme near Blackpool has involved drilling a well 2.7km down into the earth, and then using fracking to stimulate the rock around the well - a process which began in March.
A spokeswoman for Cuadrilla said the fracking had been halted while the company and the British Geological Survey examined the data from the quake.