In a study that echoes earlier research in the United States, seismic scientists in Calgary have confirmed that hydro-fracturing rock for fossil fuels—the process better known as fracking—caused a series of earthquakes near the Alberta town of Fox Creek in 2014 and 2015.
“Analyzing seismic data for the time period,” Cantech Letter reports, researchers based at the University of Calgary “attributed the series of earthquakes to two separate phenomena. Instantaneous quakes were found to result from increases in underground pressure along fault lines caused by the ongoing fracking operations, while 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 findings suggest a similar outlook for Alberta to the experience in Oklahoma, where the injection into rock formations of pressurized waste fracking fluid was conclusively linked to an increase in earthquakes in the great plains state from two or three per year, to several every day. Recently, the occurrence of fracking-linked earthquakes near the state’s Cushing oil storage hub raised concerns for U.S. national energy security.
The new Alberta findings “should inform future policy decisions around the industry,” University of Calgary seismologist David Eaton, who co-authored the study, told Cantech Letter. “It’s our hope that we can take this knowledge and use it to improve the existing regulations. We’re also hoping it will improve both risk assessment and mitigation strategies by industry.”
Experience in Oklahoma, however, shows that once high-pressure injections into new and existing underground fault lines begin, the earthquakes they cause may be hard to stop. Oklahoma now faces “many, many years of earthquakes as that energy dissipates through the system,” said one researcher. The same may be in store for Alberta and British Columbia, where hydro-fracking is widespread.