New Zealand Celsias

While oil and gas companies continue to deny any possible connection, a British seismologist has linked two minor earthquakes that occurred last spring in northwest England with the use of hydraulic fracking in the area.  Brian Baptie, seismic team leader with the British Geological Survey, said in an article in the New York Times, that two quakes near Blackpool, England appear to have been caused by nearby fracking operations being conducted at a nearby well by Caudrilla Resources. 

During fracking, sand, water, and chemicals are injected at high pressure into shale rock in order to split it and release trapped gas.  Baptie said that the high-pressure injection of water could have reduced stresses on a fault close by, causing it to slip.  While the quakes registered only magnitude 2.3 on April 1, and 1.5 on May 27, Caudilla postponed all fracking operations at the end of May, according to a company news release “while it interprets seismic information received from monitoring information located around the site.”  The three wells drilled by the company are the only shale-gas wells so far in Britain.  In May, the World Wildlife Federation (WWF) in Scotlandcalled for banning fracking in that country, and the practice has already been banned in France.

Fracking has been linked to seismic activity in the U.S. and Canada as well as in the U.K.  In Trinidad, Colorado a 5.3 earthquake that occurred last August was considered unusual yet consistent with historic activity in the area, but the U.S. Geological Survey (USGS) is still investigating whether the disposal of fracking fluids in local gas fields might have had something to do with the temblor.  A September 2001 swarm of earthquakes in the region is still being investigated. 

According to a 2002 USGS report, “In recent years, a large volume of excess water that is produced in conjunction with coal-bed methane gas production has been returned to the subsurface in fluid disposal wells in the area of the earthquake swarm.  Because of the proximity of these disposal wells to the earthquakes, local residents and officials are concerned that the fluid disposal might have triggered the earthquakes.” 

Last March oil and gas regulators in Arkansas instituted an emergency moratorium on fracking to examine whether injection wells might be linked to a swarm of earthquakes in that state.  Scientists found that the quakes were most likely caused not by fracking but by the disposal of wastewater from the process into other wells.  The wells in question have been shut down.

Finally, in Canada, the British Columbia Oil and Gas Commission has reported in an article in theVancouver Sun, since 2009 there have been 31 earthquakes in the Horn River Basin, an active natural gas extraction area.  The organization plans to work with the Pacific Geoscience Centre, which monitors and researches earthquakes, to investigate whether hydraulic fracking could trigger earthquake activity.

Photo credit: Earthquake- Bigstock photo