Trio of quakes shake northern Alberta

A series of earthquakes in northern Alberta could be felt in Edmonton Thursday morning.

The quakes struck around 45 kilometres west of Peace River, with more than 100 Albertans reporting feeling the event and with at least one report coming in from as far south as Calgary.

Natural Resources Canada said the first quake had a magnitude of 4.5 and happened at 8:46 a.m. It was followed by a 4.6 magnitude event at 8:59 a.m. and a smaller 3.8 magnitude event at 9:07.

"They were close enough that everybody in town felt it," said Benjamin Proulx, communications coordinator for Peace River. "And then there was ensuing tremors as well."

Proulx said quakes are not uncommon in the region, and they're something the municipality is prepared for.

"Luckily there seems to be no damage," he added. "We've heard of no injuries, and so as far as an earthquake can go, we lucked out on this one."

Natural Resources Canada has not reported any damage from the quakes.

Jeff Gu, a professor of geophysics at the University of Alberta, said the Peace River region has been fairly active with some larger seismic events over the last year.

In November 2022, a 5.6 magnitude quake 40 kilometres south east of Peace River. According to the Alberta Energy Regulator (AER), it was the largest event reported between 2006 and 2023.

"They're still not very common," he added. "I would say that magnitude 4s and large 3s are still earthquakes that are interesting and don't come in very often in our province."

Gu said initial information on magnitude, location and depth can change as more data comes in, so it will take some time to determine if the quakes are natural or induced.

If they are linked to industry, Gu said it's unlikely to be from fracking activity.

"We've seen in our province, a couple of locations where disposal wells have been linked to increased seismicity," he said, adding that this type of well has also been connected to earthquakes in the U.S.

The AER is investigating to determine the cause of the seismic events, which occurred between five and 10 kilometres underground., said Andrew Schaeffer, an earthquake seismologist with Natural Resources Canada.

"This area of Alberta, it does have background earthquakes that are associated with the building of the Rocky Mountains hundreds of millions of years ago so we can have natural earthquakes," Schaeffer said. "And, of course, with industrial activity it's possible to have induced earthquakes."

Schaeffer said the region may see smaller quakes in the region as an aftershock sequence, but they will likely not be felt or be felt only mildly.

Anyone who felt the quakes can report them to Natural Resources Canada here. Reports can also be made on the AER website.

With files from The Canadian Press and CTV News Edmonton's Marek Tkach