The oil and gas industry and its supporters would like to dismiss the fact that many new earthquakes sweeping across the nation are fracking-related. It has already been shown that underground injection of fracking wastewater can induce seismicity, but a new, significant study by researchers at the University of Calgary has linked fracking to earthquakes in Western Canada.
In May of 2015 Food & Water Watch released research on fracking and earthquakes. In it we explained that fracking itself could induce seismicity, but that these tremors tended to be smaller and less frequently felt than those produced from underground injection control wells.
The new University of Calgary study reaffirms that fracking can trigger “stress changes” or “pore-pressure changes due to fluid diffusion along a permeable fault zone” resulting in – you guessed it – earthquakes. Likewise, just five months ago a Seismological Research Letters study linked fracking (not injection of fracking waste) to most of the induced seismicity in Western Canada.
However, fracking-induced earthquakes are not only occurring in Western Canada, nor are these the only recorded incidents or studies on the matter. In 2011 fracking was associated with a 3.8 magnitude earthquake in British Columbia, two earthquakes large enough to be felt in Blackpool, England, and another one that was large enough to be felt in Garvin County, Oklahoma.
In 2014 a Seismological Research Letters study found that fracking was the likely culprit of about 400 small tremors from October to December 13, 2013. Of those, 190 occurred within a 39-hour period after fracking began at a nearby well. Although the tremors were not large enough to be felt by residents, one of the authors said in a press release, “…the earthquakes were three orders of magnitude larger than normally expected.”
Later that year, two fracking-induced earthquakes in Poland Township, Ohio caused the Ohio Department of Natural Resources to order a company in the vicinity to cease drilling and fracking in the Utica Shale until a cause was pinpointed. Fracking had activated a previously unknown fault causing a swarm of 77 earthquakes in just eight days.
But we’d be remiss in discussing fracking and earthquakes without going into further detail about Oklahoma, arguably the most notorious example of “frackquakes.” On September 3 of this year this state experienced its largest ever recorded earthquake with a magnitude of 5.8. And just this month the state experienced a 5.0 magnitude earthquake in a major oil hub that’s home to a “massive oil storage facility” – Cushing, Oklahoma.
In Oklahoma, a state known for its seismic activity, the sudden and violent increase in frackquakes have largely been triggered by the high-pressure disposal of toxic fracking wastewater into the ground.
From 1975 to 2008, Oklahoma averaged only one to three 3.0 magnitude (or greater) earthquakes annually. In 2009 the state had 20 of these 3.0 magnitude or greater earthquakes (the magnitude that is generally needed to be felt). In 2015, that number exploded 45-fold to 902. From 2009 to 2014, as earthquake activity increased drastically, wastewater injection volumes grew by about 43 percent.
The oil and gas industry and fracking proponents argue that fracking itself did not caused these particular earthquakes. For that reason, it is important to point out that you cannot frack a well without producing large volumes of wastewater. And that wastewater must be disposed of. It is typically done so through underground injection.
With all of this said, we now have plenty of indisputable science showing that fracking itself also causes earthquakes. And while there may be a lot more to learn regarding the precise nature of the relationship between fracking and seismicity, there is enough evidence to know that the two are intricately connected.