Fracking – a highly probable cause of earthquakes

In a development that is likely to send shivers down the collective spine of organisations like Treasure the Karoo Action Group (TKAG), the controversial fracking technique is back in the news. This time not because of potential pollution of groundwater resources, but for being suspected of causing something even more scary – earthquakes.

An independent scientific report has found that the controversial exploration technique, which itself in essence amounts to human-induced mini earthquakes, was the highly probable cause of earth tremors which hit the UK’ss Lancashire coast earlier this year.

One tremor of magnitude 2.3 on the Richter scale hit the area on April 1 followed by a second of magnitude 1.4 on May 27, prompting locals and environmental campaigners to blame the fracking technique being used locally by an oil and gas firm.

Cuadrilla Resources – the UK company licensed to explore Lancashire’s shale gas resources – said an independent report it commissioned into the events had pointed to “strong evidence” that the two minor quakes and 48 weaker seismic events resulted from the injection of drilling fluids into shale rocks.

Cuadrilla suspended its fracking operations after the two quakes.

The firm commissioned a report by independent experts to investigate any possible links between the tremors and fracking activity in the Lancashire area.

A summary published by the company said it is probable the fracking caused the tremors. It said: ''The report concludes that it is highly probable that the fracking … triggered the recorded seismic events.

''This was due to an unusual combination of factors including the specific geology of the well site, coupled with the pressure exerted by water injection.

''This combination of geological factors was rare and would be unlikely to occur together again at future well sites.

''If these factors were to combine again in the future, local geology limits seismic events to around magnitude 3 on the Richter scale as a worst-case scenario.''

Fracking involves extracting gas reserves from underground by a process of hydraulic fracturing of shale rock using high-pressure liquid to release gas - a process green groups world-wide, including South Africa, claim is damaging the environment.

The findings will add to the growing global debate about fracking. Shale gas is trapped in rocks thousands of feet underground and is released by fracturing rocks using high-pressured water, sand and chemicals.

The process has been heavily criticised by environmental groups. In May, France became the first country to ban fracking.

The Financial Times last week reported that Nick Molho, head of energy policy at WWF in the UK, described the findings as “worrying”, adding that the government should resist “the siren calls of the fossil fuel industry”.

However, Professor Andrew Aplin of the School of Civil Engineering and Geosciences at Newcastle University, cautioned that while no “industrial process is without risk ... events which can be directly related to fracking – earthquakes, subsurface escape of gas or drilling chemicals – are rare.”

It would seem that a whole new front in the ongoing battle over the use of fracking as an exploration technique is opening up and it is probably highly likely that it will also arrive in South Africa in the not to distant future.

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Comments (2)

• |2011-11-08 11:48:43 dave@mimicking.co.za  - Fracking
  Don't let this nonsense start in the Karoo - get the frack out of there Shell......
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• |2011-11-08 11:50:04 Dave E.  - Fracking
  Don't start this nonsense in the Karoo - get the frack out of here Shell......
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