Cuadrilla Tremor is 3rd Red Light Event

After 0.8 magnitude micro-tremors on October 26 and October 27, UK shale gas explorer Cuadrilla has confirmed its largest tremor since 2011.

“Cuadrilla can confirm that a micro seismic event measuring 1.1ML (local magnitude) was detected at about 11.30am today (Monday, October 29) whilst the team were hydraulically fracturing at our exploration site in Preston New Road, Little Plumpton, Lancashire," the company said.

"This will be classed as a ‘red’ event as part of the traffic light system operated by the Oil and Gas Authority but as we have said many times this level is way below anything that can be felt at surface and a very long way from anything that would cause damage or harm," it added. It however confirmed that it is pausing fracking for 18 hours in line with OGA rules that require fracking to be suspended, if seismicity is at or exceeds 0.5 magnitude.

The British Geological Survey (BGS) October 29 recorded four tremors in a half-hour interval starting 11.30am: the 1.1 tremor, two very minor 'negative magnitude' tremors , and a 0.1 one - all at the same depth of 2km below the surface.  The most powerful quakes induced by Cuadrilla's previous fracking in 2011 were 1.5 and 2.3 magnitude tremors. It resumed fracking Oct.15 2018.

BGS data show that a 0.8 magnitude tremor occurred at the Cuadrilla site on October 27 occurred at 10.55am on October 27, similar to one it had registered the previous day. That would also have been enough to trigger a halt to fracking under OGA rules - but the company halts its fracking operations anyway at 1pm Saturday and all day Sundays/bank holidays.

BGS data from recent days are shown below.