A seismic event with a magnitude of 0.4 on the Richter Scale was detected in Lancashire today close to where the energy firm is fracking for gas in shale rock.
Because it coincided with pumping operations at the site, and appears to have occurred within Cuadrilla's operational boundary, this is considered an Amber event in accordance with the Traffic Light System of safety monitoring.
Cuadrilla said it had "adopted extra caution" and stopped fracking for the day. A spokesman for Lancashire For Shale said: "A 0.4 magnitude event like this is so small it is only possible to detect it using very sensitive instruments like those deployed locally by Cuadrilla and the British Geological Survey...read more>>>...