Will fracking cause earthquakes?
There is a small possibility that fracking might trigger seismic activity, but if it does, it will only produce very minor tremors and not earthquakes. Experts agree that these minor tremors are unlikely to be felt, and will not be capable of causing damage to people's homes at the surface.
Since 2011, when test fracking in Lancashire was linked to two small tremors in April (magnitude 1.1) and May (magnitude 2.3), a number of things have changed and improved which mean a repeat is very unlikely. For a start, companies wishing to undertake fracking must first perform geophysical surveys to create a 3D map of the subsurface in order to plan their activities and avoid any underground faults in the rock. And, they must also observe a Traffic Light System agreed with the government which sees operations temporarily halted if seismic activity with a magnitude of just 0.5 is detected. We don't believe they have these same controls in other parts of the world.
It's also important to note that when people point to so-called 'earthquake swarms' in Oklahoma, not only is the geological setting very different, but they have not been caused by fracking to extract gas - they are all associated with the use of deep injection wells for disposal of oil and gas industry wastewater, a practice that is outlawed in the UK.
While fracking has been linked with earth tremors in the UK before, they have been minor and look unlikely to be repeated.