Alberta's provincial energy regulator says a significant earthquake in northern Alberta was likely caused by hydraulic fracturing.
If fracturing is confirmed as the cause, scientists say, it will have been the largest earthquake ever to result from using the method.
Residents in the town of Fox Creek noticed the earthquake a week ago on Jan. 22. It was of 4.4 magnitude, severe enough to cause minor damage.
"It felt like a big gust of wind hit the house. The door flew open and the couch moved," said Kelli Mcphee, who was at home watching a scary movie in her living room at the time.
“My husband grabbed a bat and started walking around the house because we didn't know what it was.”
Fox Creek, a town of about 2,000 people, is largely sustained by oil and gas development.
That work often uses hydraulic fracturing, or “fracking,” a process that injects a high-pressure mixture of water and chemicals into the earth to break through rock.
In an emailed statement to CBC, the Alberta Energy Regulator said its monitoring system picked up strong evidence that fracking caused this recent earthquake and likely triggered others too, although it is "impossible to definitively state that it was not a naturally occurring event."
The link between fracking and earthquakes is a phenomenon that several scientists are now studying.
“We have been seeing earthquakes for about the last year in that area, starting with events just above magnitude 3,” said David Eaton, a professor of geophysics at the University of Calgary.
“In most cases, those earthquakes have occurred in association with industry activity such as hydraulic fracturing.”
Eaton and Gail Atkinson, a seismologist at Western University, said if the quake is proved to be caused by hydraulic fracking, it would be the largest one in the world caused by the method.
British Columbia has a policy that requires operations to halt if they trigger an earthquake greater than a 4.0 magnitude.
Alberta does not have a similar rule.
An earlier version of this story stated that the earthquake was linked to fracking. In fact, fracking has been identified as the likely cause. Additionally, the earthquake would be the largest linked to hydraulic fracturing, not the largest linked to any industrial activity, as a previous version of this story stated.Jan 31, 2015 11:38 AM MT