On November 11, Earthquakes Canada reported a magnitude 4.7 earthquake 132 kilometers northwest of Fort St. John. It was followed four days later by a magnitude 4.6 earthquake recorded just one kilometer away from the first seismic event. “There is an active hydraulic fracturing function nearby,” said Professor Honn Kao, a researcher at the Geological Survey of Canada. “The likelihood that these two events are caused by industry is very high.” Earthquakes Canada said that while tremors were “slightly felt in the surrounding area”, there were no reports of damage. Fracking involves injecting fluids into a deep well under high pressure to fracture tight rock formations and release the natural gas inside. Hydraulic fracturing, known as fracking, injects water, sand and chemicals at high pressure several kilometers into the earth to break up rock and release gas, shown in this 2014 file photo from North Dakota. (Andrew Cullen/Reuters) According to the BC Oil and Gas Commission (BCOGC), the province’s energy regulator, fracking in BC takes place deeper underground than in other parts of the world — sometimes more than four kilometers below the surface. According to information on the BCOGC website, “microseismic events” occur when fluid fractures the rock. “In some cases, where there is a vulnerable preexisting fault, slip can occur on the fault plane,” he says. BC’s energy regulator says the majority of the province’s natural gas wells are in the Montney region in the northeast. (BC Oil and Gas Commission/Contributed) While the vast majority of fracking operations do not cause earthquakes, the practice has been linked to most of the largest seismic events in Alberta and northeastern BC. during the last decade. Cao said the timing and location of the fracking operations fit the context of the November earthquakes. He said additional data from the drilling company would help determine a “definite causal relationship.” In a written statement, a BCOGC spokesperson told CBC News that the company fracking in the remote area on Nov. 11 “immediately suspended operations” after the first quake, but later resumed activity. The name of the company has not yet been released. Kao said the November earthquakes were not large enough to destroy critical infrastructure or affect local communities, but they were significantly larger and closer together than other fracking-induced earthquakes in the region. “Certainly it should be considered significant because, with a 4.6 or 4.7 magnitude earthquake, we’re basically reaching the upper limit [of magnitude] of what we have observed in the last decade in Western Canada. “Having two major events happen within a week in the same area tells us something.” Cao said the last 4.6-magnitude earthquake in the region was recorded in 2015. It was considered one of the largest fracking-induced earthquakes ever recorded in Canada at the time, he said. He said he hopes further research will help the industry mitigate or minimize the potential for seismic events.
