Gas drilling halted after quakes

MSN News: Gas drilling halted after quakes

The UK's only "shale" gas drilling project has been suspended after a small earthquake was registered in the area.

The British Geological Survey (BGS) recorded a 1.5 magnitude quake last Friday which was felt by at least one person and whose epicentre was within 1.2 miles of where gas exploration is taking place near Blackpool, Lancashire.

As a result, the process for extracting the source of gas by fracturing rock deep underground using high-pressure water, known as "fracking", has been halted, said the company behind the scheme, Cuadrilla.

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."

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 (1.2 miles).

"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 1.7 miles down into the earth, and then using fracking to stimulate the rock around the well - a process which began in March.