BBC Radio 4. Credit: BBC Radio 4The Times, Matt Ridley
Last Saturday, BBC Radio 4 ran throughout the day with headline news about the shale-gas company Cuadrilla causing “micro-earthquakes” in Lancashire, as if the ground was trembling. It wasn’t. The tremors from fracturing gas-soaked shale rock more than a mile below the surface, picked up by ultrasensitive sensors, were far too weak to be felt at the surface. They were never going to threaten the integrity of the steel and concrete casing of the gas well itself, as some activists have since claimed.
The vibrations were tens of thousands of times less powerful than the kind of tiny earthquake that, according to the official Richter scale, “almost never cause damage”. They were smaller than the vibrations that can be routinely caused by quarrying, artillery training, mining, tunnelling, passing lorries, underground trains, geothermal wells, pile driving and building works. (Even thunder can cause seismic waves.)
There was a 3.1 magnitude natural earthquake on September 15 at 6.39pm near Newton Aycliffe in Durham. That’s several thousand times as powerful as anything caused by the recent fracking. Nobody reported feeling it, according to the British Geological Survey.
British regulations say that anything over 0.5ML (local magnitude) triggers a “red traffic light”. This has been interpreted as meaning that fracking must stop for good. Not so. As the geophysicist James Verdon from Bristol University explains, when the traffic light goes red, you don’t scrap your car, you stop for a short period till the light changes, then drive on. That’s exactly how the shale-gas traffic light is designed: if there is a tremor, then the company fracking the well must pause for some hours to let further vibrations settle, before resuming work.
Britain’s threshold of 0.5 is far more sensitive than that used in other countries, such as Canada. As Francis Egan, the chief executive of Cuadrilla, points out, if any other industry had to stop work when it triggered 0.5ML vibrations, then “you’d never get a wind farm built, you’d never get Crossrail built” and many HGVs would be off the roads.
The Russians are spreading anti-shale propaganda to protect their exports. Yet because a few fanatics have decided to campaign furiously against fracking, are we to turn our backs on this vital industry?