Does fracking cause earthquakes?
In a result which may impact the regulatory framework for the oil and gas sector, researchers at the University of Calgary have shown how a string of earthquakes occurring in Northern Alberta over the past few years were caused by fracking. The findings could push for a reconsideration of how the extraction process is regulated in Alberta and in other regions of the country, say the study’s authors.
Published in the journal Science, the new study looks at a series of earthquakes occurring in late 2014 and early 2015 near Fox Creek, where companies were drilling into the underground Duvernay shale formation by the process known as hydraulic fracturing. Fracking involves the injection of pressurized water, chemicals and sand into deep rock layers in order to break them up, releasing natural gas as a result.
Analyzing seismic data for the time period, the researchers attributed the series of earthquakes to two separate phenomena. The more instantaneous quakes were found to result from increases in underground pressure along fault lines caused by the ongoing fracking operations, while the later-occurring quakes (up to months after drilling) were found to stem from the long-term presence of fracking fluid, left underground, which brought about pressure changes in the rock formations.
The new findings are a key indicator of the impact that, potentially, fracking can cause earthquakes and should inform future policy decisions around the industry, says U of C seismologist and study co-author, David Eaton. “It’s our hope that this work is going to contribute to science informed regulations, so that we can take this knowledge and use it to improve the existing regulations. We’re also hoping that it will improve both risk assessment and mitigation strategies by industry,” says Eaton.
The study results indicate that the Alberta quakes were brought about through different means than those that have been recorded in the United States in connection with extraction operations. There, the cause has been attributed to the burial of wastewater from oil and gas extraction processes (including fracking), which once injected underground can disrupt rock formations around fault lines.
In Oklahoma, some of the largest quakes in the state’s history have occurred during the past half-decade, in connection with oil and gas extraction. The New York Times reports that in 2010, Oklahoma recorded three earthquakes at or above a magnitude of 3, whereas last year, it had 907. In January of 2016, the state’s regulators have asked well operators in some regions to reduce by 40 per cent the amount of oil and gas wastes they are burying underground, a turnaround from the government’s previous position, which maintained that the cause of the quakes was still undetermined.
In Canada, provincial approaches to handling the controversial debate are mixed, with some imposing moratoria on fracking while others are supportive of the industry. The mixed bag of approaches isn’t surprising, says Jennifer Winter, assistant professor and director of the Energy and Environmental Policy Area at U of C’s School of Public Policy, since there is still a lot about the environmental consequences of fracking that remains unknown. “Hydraulic fracturing is a big issue is Canada; and what’s really telling is the different policy reactions to it, from a moratorium on hydraulic fracturing in New Brunswick to the ongoing fracturing in a majority of wells drilled in Saskatchewan, Alberta and B.C.”
A poll conducted earlier this year in BC, where extensive fracking operations are ongoing, showed that only 23 per cent of people surveyed supported fracking in the province while 61 per cent were opposed.