Alberta’s largest-ever earthquake: Will it happen again?

A rare 5.6-magnitude earthquake that’s been reported as the largest ever recorded in Alberta could occur again, suggested Glenn McGillivray, managing director of the Institute for Catastrophic Loss Reduction.

Earthquakes Canada reported the moderate earthquake near the hamlet of Reno in northwestern Alberta on Nov. 29. At least eight other smaller earthquakes and aftershocks occurred that same day or the following day.

There is some discrepancy among experts as to the size of the quake, with the highest estimate being M5.8. The earthquake is believed to be ‘natural’ and not from resource extraction such as fracking.

Would any insured losses be expected from this event?

“I do not expect any insured damage, or at least no significant insured damage from this event,” McGillivray said. “On the homeowners side, very few — if any — would have purchased cover for ‘shake’ in the impacted region, which is a separate coverage added by an endorsement.”

Also, typical policies for shake in Canada have pretty high attachment points, with deductibles not being a flat dollar rate (like $500 or $1,000) but based on a percentage of the policy limit, such as 2%, 5% or even 10%.

“Damage generally has to be significant before the policy would kick in,” McGillivray said. “That wasn’t the case here.”

Canadian Underwriter asked if more earthquakes could happen in Alberta.

“Certainly,” McGillivray said. “If this earthquake was indeed a ‘natural’ event, there is no reason to believe that it couldn’t happen again. What’s more, resource extraction will trigger more events in the future. Since 2006, Alberta has experienced an average of about 165 earthquakes each year.”

McGillivray noted that many people made the immediate assumption that the quake was caused by resource extraction but there is no evidence to back this up. Earthquakes Canada confirmed “the provincial energy regulator has stated there is currently no evidence that the activity was induced but that further analysis is needed.”

Rebecca Salvage, a postdoctoral associate at the University of Calgary’s Faculty of Science, told The Canadian Press the quake originated near Peace River at least six kilometres underground, meaning it’s probably too deep to have been artificially caused. “The depth infers that it’s probably natural,” she said. “Natural events typically occur at those depths.”

Scientists are aware of geologic faults in the area but quakes like this are rare in Alberta, Salvage said.

One area landowner, Carmen Langer, reported the quakes caused light fixtures in his home to swing and the glass in windows to flex, CP said. Earthquakes Canada said they had received no reports of damage at the time. But the quake was “strongly” felt close to Reno and lightly felt in eastern British Columbia and western Alberta.

The largest earthquake previously recorded (M5.4) occurred in Alberta’s Peace Region on April 11, 2001. Media reports from the time said no structural damage was reported, but the quake shook homes, knocking pictures off walls and rattling dishes.

Feature image by iStock.com/allanswart