The ninth part in our series in which Nick Grealy, of No Hot Air, tests the weight of some of the biggest arguments pitted against fracking.

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#9 – Shale production causes earthquakes

Haven’t you heard? Fracking causes earthquakes.

So far, two earthquakes in Lancashire UK have been linked to fracking activity. These were 1.5 and 2.4 Richter.

Quakes under 3 are classified as imperceptible and the British Geological Survey is unable to distinguish between quakes of less than 2 and passing traffic from seismometers in urban areas. As the Richter scale is exponential, most people aren’t aware that the difference in the energy released between a 2.4 quake and damaging earthquakes is a factor of several million.

How does fracking cause earthquakes?

This isn’t entirely clear, but Cuadrilla, the company conducting fracking in the area reported that it wasn’t the process of splitting the rock that was causing the problem, or the drilling. Actually it seems more likely to have been caused by the injection of water into the fault which lubricated the rocks and caused them to move past each other.

Why haven’t earthquakes been recorded at fracking sites before?

Well presumably partly because the earthquakes caused aren’t strong enough to even shake the ground. But the British Geological Society survey carried out on the Cuadrilla sites suggest that the problem is caused when drilling occurs into an existing fault. Cuadrilla are now monitoring seismic activity at their site and propose this practise be adopted worldwide. If earthquakes continue or change in intensity, production can be stopped.

This post is part of our series: 12 myths surrounding shale gas production, by Nick Grealy. Download the ebook here >