by Laura Walz [email protected] A magnitude 6.4 earthquake struck just off the west coast of Vancouver Island at 12:41 pm on Friday, September 9. Initial reports indicated the quake was 6.7, but those estimates were later downgraded.
Many Powell River residents felt the quake, which caused gentle swaying, items to fall from shelves and water in fish tanks to slosh back and forth.
Chris Duffy, executive director of emergency coordination for Emergency Management BC, said the quake was located 80 kilometres south of Port Alice and was about 18 kilometers below the surface. There was no tsunami warning, watch or advisory issued, he added. “The earthquake was felt fairly strongly in the Port Alice area and the surrounding area,” he said. “But there are no reports of damages at this time.”
Marie Claxton, City of Powell River’s city clerk and emergency communications officer, and Ryan Thoms, Powell River Regional District emergency program coordinator, sent out email advisories, both of which noted there were no reports of damage and that there had been no tsunami warning.
Dan Ouellette, the city’s director of fire and emergency services, said staff at the fire hall on Courtenay Street felt the earthquake. “We have our own internal policies that if there is any sort of shake at all, we immediately move all of our equipment outdoors, meaning fire apparatus and staff, until we know a little bit more,” he said. “We’ll do that for the remainder of the day and that’s pretty standard. That’s what we did that day.”
Other than that, there wasn’t much to do, added Ouellette. “There were no reports of damage anywhere within the community,” he said. “We had our own internal staff communications plan initiated, which is in our emergency plan, but there wasn’t really any point to initiating anything above the communications side of things.”
The department moves equipment out of the fire hall because the building is not earthquake-proof, Ouellette added. “We’re not going to take any chances,” he said. “While we may not feel much here at the fire hall, other than it’s shaking a little bit, it may cause damage in other places. To get the equipment outside in a timely fashion allows us to be able to get going should there be anything else.”
Jay Yule, superintendent of schools for School District 47, said several schools in Powell River were evacuated. “We’re really proud of our students,” he said. “It was done in an orderly way.”
Before students were allowed back into the schools, maintenance staff inspected the buildings for structural damage and checked for gas leaks. “Then students went back into school,” he said. “There were a few schools in the outlying areas that actually didn’t feel the tremor, so they didn’t evacuate. In those circumstances, we still sent our maintenance people into each of those schools afterwards to look for structural damage and ensure that the school was safe.”
John Cassidy, a seismologist with Natural Resources Canada based in Victoria, said there were several dozen aftershocks, the largest of which was a magnitude 4.9. The earthquake occurred in the Nootka fault zone, Cassidy explained, which runs offshore of Vancouver Island. “That fault zone separates two ocean plates, the Juan de Fuca plate, which is beneath southern Vancouver Island and Washington and Oregon, and the Explorer plate,” he said. “Both of those plates are being pushed beneath North America. It’s the movement of those plates that generates the big subduction earthquakes, the magnitude nines we have seen in recent years around the world.”
The big subduction earthquakes occur deeper and farther west off Vancouver Island, Cassidy said. “Today’s earthquake occurred on a fault zone that is well known and it’s more of a horizontal slipping motion,” he said.
This earthquake is relatively common, Cassidy added. “On average, about every 10 years we see an earthquake of this size offshore of Vancouver Island,” he said.
Thoms said the earthquake was a good reminder “that we live in a seismically active region. Please go to www.shakeoutbc.ca to learn more about earthquake preparedness and register for the upcoming earthquake drill on October 20.”
