Sunday’s earthquake 30 km northwest of Rocky Mountain House was felt by people as far away as Edmonton according to an online map at Earthquakes Canada. (Image contributed)

Rocky-area earthquake likely naturally occurring

The estimated depth of Sunday’s earthquake near Rocky Mountain House suggests it was a natural earthquake, rather than fracking-related as suspected in the quake a week ago near Sylvan Lake, according to an earthquake seismologist.

Earthquakes Canada reported seismic monitors measured a 4.3 magnitude earthquake 30 km northwest of Rocky Mountain House, at about 4 a.m., that was lightly felt in Rocky and Clearwater County.

Last Monday, an earthquake measured at 4.6 on the Richter scale happened just before 6 a.m. about 20 km south of Sylvan Lake.

There were no reports of damage from either quake, but the one near Sylvan Lake rattled doors and windows in that town.

John Cassidy, earthquake seismologist with Natural Resources Canada who heads the earthquake research group across Canada, said Sunday’s quake was felt as far away as Edmonton, with most reports from the Rocky Mountain House area and milder shaking compared to the Sylvan Lake event.

“The (Sylvan Lake) event we know was very close to the surface. Earthquakes that are very shallow are felt stronger,” Cassidy said on Monday.

He said it may seem like a small difference between 4.3 and 4.6 magnitude, but 4.6 is nearly twice as strong.

“We have natural earthquakes and human-induced earthquakes in (the Rocky M0untain House) region. Which this is, we don’t know at this point. If it really is 10 or 13 km deep as the initial estimates suggest, then it’s much more likely it’s certainly a natural earthquake.”

He said the two central Alberta earthquakes were also not linked.

“They’re too far apart. They are too small.”

Naturally occurring seismic activity is not uncommon for the Rocky area. In August 2014 a 4.3 magnitude quake happened.


Central Albertans saw lighter side of earthquake experience

Seismic experts investigating Monday’s earthquake

Cassidy said magnitude 4 earthquakes are not unheard of in the area, but are relatively rare. It’s an area that can feel the stresses caused when tectonic plates, or pieces of the earth’s crust, collide off Canada’s west coast.

“It’s the movement of those plates that ultimately cause earthquakes. Most of Canada’s earthquakes are along the west coast, mostly offshore. But some of the stress from those plates and forces are actually transmitted through the continent so all of North America is being squeezed ever so gently, in sort of a northeast, southwest direction.”

He said people’s experiences can vary even if they are in the same building during earthquake. Depending on the magnitude, it may be felt more by someone on a higher floor or in a quiet space.

Central Albertans are encouraged to report what they experienced in the Rocky-area quake to to assist scientists.

Like us on Facebook and follow us on Twitter

Just Posted

UPDATED: Economy and health care expected to be hot election topics

Premier Rachel Notley makes announcement on Tuesday morning

Cruel and sadistic: Central Alberta dog rescuers believe there are dog fighting rings in province

With the increased number of stolen dogs, some central Alberta rescuers are… Continue reading

Red Deer hospital expansion recognized in throne speech

Society for Hospital Expansion in Central Alberta calls for more details

Mixed Nuts revue presented Saturday to kick off first Carole Forhan Theatrical Scholarship

Broadway songs, comedy skits are part of the Red Deer Players production

Opinion: Let’s be heard ‘loud and clear’ during provincial election campaign

By David Marsden During the banquet for Sunday’s Boston Bruins alumni game,… Continue reading

Documentary on Colten Boushie case to open Toronto’s Hot Docs festival

TORONTO — A film examining the case of a young Indigenous man… Continue reading

Want to help bees? Plant flowering herbs

Herbs are among the most useful plants in nature. They can tantalize… Continue reading

UN: Gene editing for human reproduction is ‘irresponsible’

GENEVA — A panel convened by the World Health Organization said it… Continue reading

Photos: Three moose spotted in Red Deer Tuesday

Three moose were spotted in Red Deer Tuesday morning. Red Deer resident… Continue reading

Andreescu rockets to No. 24 in WTA Tour rankings after Indian Wells title

Canada’s Bianca Andreescu has rocketed to No. 24 in the WTA Tour… Continue reading

Canadian figure skaters looking to reach new heights at world championships

Nam Nguyen, Alaine Chartrand and Kirsten Moore-Towers and Michael Marinaro all have… Continue reading

Man linked to largest art heist in history freed from prison

HARTFORD, Conn. — A reputed Connecticut mobster who federal authorities believe is… Continue reading

Most Read