This is an interesting development. From the data published I cannot see them being able to establish a direct cause and effect in terms of the fracking causing the quake, but this certainly heightens concerns over the security of the environment into which they are pumping these frack fluids, and having the epicentre so close is certainly not good news for the integrity of the concrete lined borehole.
Similar sizes earthquakes, and bigger, are much more common in South Wales than most of us realise, as these articles reveal.
http://www.walesonline.co.uk/news/wales-news/2009/06/06/earthquake-hits-port-talbit-91466-23805180/ TheBritish Geological Survey later confirmed there had been an earthquake with a magnitude of three with an epicentre just over six miles north east of Port Talbot. A spokeswoman for South Wales Police said: We had three reports yesterday evening. Members of the public from the Wild Mill and Sarn area of Bridgend reported feeling a tremor.
The epicentre six miles north of Port Talbot could put this very close to a test borehole site.
Dr Roger Musson, an expert from the British Geological Survey, revealed an earthquake measuring in the region of five on the Richter scale could strike and cause significant damage to towns and cities. His warning comes after Cardigan Bay suffered a 1.7 magnitude quake and Abergavenny, Aberdare and Bangor all witnessed slight tremors of 1.6, 1.3 and 1.1 magnitudes respectively since August 22 . He said: On average Wales gets a magnitude three earthquake every three years and normally a magnitude four every 30 years. But [Wales] is also a bit unusual in some respects as it tends to get a four to five magnitude more frequently than one would expect.”
Aberdare and Abergavenny are within the potential fracking target areas.
http://www.earthquakes.bgs.ac.uk/hazard/Hazard_UK.htm In South Wales, on the other hand, although a line of epicentres of significant events can be traced from Pembroke (an earthquake in 1892) to Newport (active in 1974), only the Swansea area shows consistent recurrence, with significant earthquakes occurring in 1727, 1775, 1832, 1868 and 1906. (Given this periodicity it may be that a further earthquake in this area is due in the near future.) The Hereford-Shropshire area has also produced large earthquakes in 1863, 1896, 1926 and 1990, but none of these share a common epicentre.
Test drilling is proposed near Swansea.