4.5 magnitude earthquake detected near Grande Prairie

A minor earthquake in northwestern Alberta was felt widely across the region Thursday and even into parts of British Columbia. 

According to Earthquakes Canada, the 4.5-magnitude earthquake was detected about 40 kilometres south of Grande Prairie, just before 3:15 p.m. Thursday.

Residents throughout the Grande Prairie area felt the shaking, and the agency said it received reports from people as far away as Whitecourt, Alta., as well as McBride and Prince George, B.C. 

"I was in the work shack, and, just sitting here minding my own business, it was quiet, and all of a sudden, the shack just started shaking," said Casey McGregor, who lives in Grande Prairie. "It was kind of like turbulence on an airplane, but it was just really weird because at least when you're on a plane, you kind of expect that turbulence, and it just came out of nowhere.

"I've lived in Grande Prairie for 22 years now, and I don't remember ever having earthquakes here growing up. And now they're they're so frequent."

It's one of several earthquakes in the region in recent years.

In November 2022, a 5.6 magnitude earthquake, the largest to ever be recorded in Alberta, occurred near Peace River.

A study conducted by the University of Alberta and Stanford University found it was caused by oil and gas activity.

"There is a number of earthquakes in this area and it's an area of known induced seismicity. So this is seismicity, related to industry, fracking, wastewater disposal," said Camille Brillon, a seismologist with Natural Resources Canada.

"Within like 100 kilometres of this event, there's been 10 magnitude four and above earthquakes in the last 10 years. So there are magnitude four earthquakes in this area. Most of them are related to industry," she said.

In an emailed statement, Alberta's Energy Regulator says the Alberta Geological Survey is reviewing Thursday's incident to determine an exact cause, however it is believed to be due to disposal in wells at Secure Energy's Big Mountain facility. 

According to the company's website, the Big Mountain location is a water disposable facility.

Disposal wells are wells that have been drained of resources and then repurposed as sites, into which waste fluids can be injected for safe disposal. That waste often includes wastewater that was used in hydraulic fracturing operations.

The AER said there were no reports of damage or injury and Secure Energy has engaged their mitigation protocols.

CBC has reached out to the company for comment.