Fracking was paused at the UK’s only active shale fracking well today as another seismic tremor shook the area.
It is the third time in as many months that Cuadrilla has halted production at its Preston New Road site in Lancashire.
Geologists recorded a 1.5 magnitude tremor in the area at around 11.20am, making it the largest microquake felt at the site since fracking started in October.
“This occurred after hydraulic fracturing had finished for the day,” Cuadrilla said.
“According to recent research by the University of Liverpool the impact would be like dropping a melon.
“A series of smaller micro seismic events occurred during hydraulic fracturing, beginning at about 9.40am.”
Fracking causes cracks in the bedrock by injecting high-pressure fluid into the ground, which in turn can cause microquakes. However, these are limited by the amount of energy in the injection process, keeping them small.
But it can also trigger pre-existing faults, such as when Cuadrilla first started fracking at Preese Hall in 2011. That triggered a 2.3 magnitude event which caused the government to ban fracking across the country for 18 months.
There are between 20 and 30 earthquakes with magnitudes greater than two each year in the UK or just offshore, and several hundreds at around one, according to the British Geological Survey.