|Don’t frack with Mother Nature: Does Hydraulic Fracturing Cause Earthquakes?|
|Written by Caroline Haywood, Four Green Steps|
|Thursday, 13 September 2012 00:37|
Written by Caroline Haywood, Four Green Steps
Late last year, we reported on the environmental concerns that surround the practice of hydraulic fracturing, known as ‘fracking’, an oil extraction technique that is used to mine unconventional gas, such as shale gas, tight gas or coal bed methane.To briefly recap, fracking uses large quantities of water and it can also contaminate groundwater, if the pressure from fracking causes fissures or fractures to open up between the underground oil reservoir and the groundwater aquifers, through which hydraulic fracturing fluid or the unconventional gas itself may leak.
In addition to these concerns, a recent study by the British Columbia (B.C.) Oil and Gas Commission has linked fracking with seismic activity in the Horn River Basin, in northeastern B.C. Large numbers of small-scale earthquakes have occurred in the Horn River Basin while shale gas extraction has been undertaken. "The investigation has concluded that the events observed [in] the Horn River Basin between 2009 and 2011 were caused by fluid injection during hydraulic fracturing in proximity to pre-existing faults," British Columbia Oil and Gas Commission said in its report.
This is also not the first time that fracking has been linking to seismic activity. Following seismic activity of one magnitude 2.3 tremor and another magnitude 1.5 tremor in the vicinity of fracking near Blackpool, England, the company involved ceased fracking and commissioned a report by a team of independent seismic experts. This report concluded that it is highly probable that hydraulic fracturing triggered the tremors but that the circumstances under which the tremors arose were unusual and that future significant seismic activity is unlikely.
British Columbia is undergoing a boom in shale gas exploration and drilling in the north-east of the Province. The Horn River Basin has been touted to be one of the “top natural-gas accumulations on the planet”. Therefore, the findings of the Commission’s report are not likely to lead to any significant restrictions on drilling activity. The operators of the drilling sights claim that there is nothing to worry about. It is true that the seismic activity is very small in scale (with none more than 4 on the Richter scale) and that only one of the 272 recorded minor earth tremors that occurred in the Horn River Basin was felt by people in the area. Nevertheless, what is worrying is that any seismic activity causes faults to slip, which means that fissures or other pathways may open up between the gas deposit and groundwater, contaminating the latter. So, while fracking is unlikely to stop, more research into its connection to earth tremors will be undertaken and closer monitoring of seismic events will take place in B.C.’s oil and gas fields. This reporting and monitoring should be followed closely.
The development of unconventional gas exploration in Canada and around the world is likely to have profound impacts on the air, surface, and subsurface environments. Overall, the true environmental costs of fracking remain relatively unknown and there is a great deal of scientific uncertainty surrounding the possible causal relationship with earthquakes in particular. Society should question whether it is wise to move forward with unconventional gas development before seriously attempting to identify its potential impacts on our environment.
 Tom Bawden, “Exclusive: Fracking company – we caused 50 tremors in Blackpool – but we’re not going to stop: Gas drilling not a threat, says energy company”, The Independent (3 November 2011) online: The Independent <http://www.independent.co.uk>.
 B.C. Ministry of Energy and Mines, “Ultimate Potential for Unconventional Natural Gas in North-eastern British Columbia’s Horn River Basin” (National Energy Board, 2011) at 1.
 Peggy Williams, “Horn River Shales” (2009)29:5 Oil and Gas Investor at 32.
 Mark Hume, “Earthquake threats won’t stall fracking in B.C., industry officials say”, The Globe and Mail (3 September 2012) online: The Globe and Mail
Image courtesy of Creative Commons.
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