Five shale gas sites in Ohio have been closed following a spate of earthquakes which hit the American state on New Year’s Eve, according to reports. Ohio governor John Gasich closed the sites after a magnitude 4.0 quake struck near a site used in the controversial shale gas ‘fracking’ process, reported the Associated Press.
Fracking, or hydraulic fracturing, is a way of extracting natural gas by pumping highly pressurised water into tight shale rock deep underground. Shale gas use has rocketed in the States over the last decade but the fracking process concerns some environmentalists who worry it could contaminate groundwater supplies.
It calls to mind a similar event in the UK last year when two tremors happened near the Blackpool shale gas drilling site run by Cuadrilla Resources, the first firm to explore shale gas potential in Britain. Cuadrilla commissioned independent research which found it was ‘highly probable’ the drilling was the root cause of the small quake.