A British seismologist said Friday that two minor earthquakes in
northwestern England “appeared to correlate closely” with the use of
hydraulic fracturing, a method of extracting natural gas from wells
that has raised concerns about environmental and seismological risks
in the United States.
The scientist, Brian Baptie, seismic project team leader with the
British Geological Survey, said data from the two quakes near
Blackpool — one of magnitude 2.3 on April 1, the other of magnitude
1.5 on May 27 — suggested the temblors arose from the same source.
Cuadrilla Resources, a British energy company, was conducting
hydraulic fracturing, or fracking, operations at a well nearby when
the quakes occurred.
In fracking, water, sand and chemicals are injected into a well at
high pressure to split shale rock and release trapped gas. The company
suspended its fracking operations shortly after the second earthquake,
which, like the first, was barely felt and caused no damage. Paul
Kelly, a Cuadrilla spokesman, said a report by several academic
scientists on the quakes, commissioned by the company, should be
released in a few weeks.
“We’re waiting for the independent report,” he said.
One possibility is that the British government, through the Department
of Energy and Climate Change, might require modification to the
fracking process. Mr. Kelly said Cuadrilla Resources had drilled three
wells — the only shale-gas wells so far in Britain — and had conducted
fracking operations at only one.
In the U.S.
Fracking is now widespread in the United States, and has been blamed
by some landowners, environmentalists and public officials for
contaminating waterways and drinking water supplies. Some critics have
also said that the technology could cause significant earthquakes. But
Stephen Horton, a seismologist at the University of Memphis, said,
“Generally speaking, fracking doesn’t create earthquakes that are
large enough to be felt.” Even so, Mr. Horton said that after looking
at the British Geological Survey’s analysis of the Blackpool
earthquakes, “the conclusions are reasonable.”
Mr. Horton and others investigated a swarm of earthquakes in 2010 and
2011, including one of magnitude 4.7, in an area of central Arkansas
where fracking was being conducted. The scientists found that the
earthquakes were probably caused not by fracking but by the disposal
of waste liquids from the process into other wells. Those wells have
since been shut down. — New York Times News Service