A second earthquake in seven days has struck the central Alberta region, this time near Rocky Mountain House.
Earthquakes Canada tweeted the following on Sunday morning:
Michele King, who lives near Cow Lake southwest of Rocky Mountain House, says she felt the quake and it sounded like someone driving a car into her house.
“It scared me so bad, I jumped out of bed and ran to look outside to see if there was someone in our farm yard. I couldn’t see anybody. I walked around the house a little bit and nothing looked abnormal. My dog didn’t even move,” she said.
“I went back to bed and it took me a few minutes and then I thought it was probably an earthquake. I wasn’t sure if I had been imagining things.”
While there have been many reports from people feeling shaking, there have been none of power outages or damages, according to Dr. Honn Kao, a research scientist with the Geological Survey of Canada.
“Certainly for Alberta, two magnitude larger than 4 occurring within a week is considered to be unusual, but we have to realize that the western part of Alberta is very close to the Rocky Mountains which has historically had seismic activities,” says Kao. “Although I would consider two in a week relatively unusual, I don’t think it should be characterized as impossible.”
He continues, explaining that it’s highly unlikely the Rocky quake would be considered an aftershock of last Monday’s quake.
“Simply because these two epicentres are more than 80 km away from each other,” Kao says. “For an earthquake this size, the rupture area is simply too small. Therefore, physically they should not be considered as main-shock and aftershock.”
Kao adds that the Alberta Energy Regulator has been contacted regarding any industrial activity in the area around the epicentre, but the preliminary answer from the AER, he says, is that there isn’t much happening near there.
However, he did note that a depth of 10 km is considered ‘shallow’ by industry standards.
AER spokesperson Cara Tobin confirms they are investigating Sunday’s quake.
“The area is well-known for naturally-occurring seismic activity,” she says, noting a Magnitude 4.3 tremor that struck near Rocky Mountain House in August 2014. “We are not aware of any industrial activity (currently) in the area.”
Tobin notes there was some industrial work involving drilling or completion activities near the epicentre as recently as four weeks ago. But at this point she says it’s too early to definitively say whether the quake was natural or caused by something else.
Last Tuesday, the Alberta Energy Regulator ordered Vesta Energy Ltd. to suspend fracking operations at a well site near Monday’s quake which hit south of Sylvan Lake.
The investigation is still ongoing into whether that earthquake was naturally occurring or caused by fracking.
If you experienced anything possibly earthquake-related on Sunday morning, you can report it online at www.EarthquakesCanada.nrcan.gc.ca.
