Increased seismic activity on Pacific west coast concerns Canadians and Americans
By Mercedes Deutscher, News Editor
On December 29, a magnitude-4.7 earthquake was widely felt throughout the Lower Mainland at 11:39 p.m. The earthquake, which occurred about 20 kilometres north of Victoria, was felt from as far as Seattle and Abbotsford, with an epicentre 50 kilometres underneath the earth’s crust.
There were no injuries or damage caused by the earthquake, nor a tsunami. Yet the activity brings concern to many. There has been speculation of a severe earthquake with the potential to reach a magnitude of 9.0 in the region for years. A large scale quake occurs in the Cascadia coastal subduction zone—a zone between the north of Vancouver Island and Northern California that pulls plates underneath each other—on average every 500 years, but as frequent at every 20 or as rarely as 800. The last major earthquake occurred in 1700.
“When the next very big earthquake hits, the northwest edge of the continent, from California to Canada and the continental shelf to the Cascades, will drop by as much as 6 feet and rebound 30 to a 100 feet to the west—losing, within minutes, all the elevation and compression it has gained over centuries,” wrote Kathryn Schulz in “The Really Big One,” a feature published in The New Yorker July 2015. Schulz also predicted that the large earthquake will result in a dual-tsunami, with one side heading toward Japan and a large one heading east towards the North American West Coast.
According to CBC, the province’s Earthquake Emergency Response Plan modelled a worse-case scenario earthquake—a shallow earthquake that struck under Vancouver. They discovered that this could result in 10,000 casualties, crack roads, destroy buildings, and compromise electric and gas infrastructure.
The recent earthquake led to many families finally putting together an earthquake kit. Families are advised to have a disaster kit that contains enough food, water, and supplies to last 72 hours. Car owners are also advised to carry a similar kit in their vehicles.
“I don’t know if you got woken up or not, but literally this can be considered a wake-up call for every one of us who live in this region that we are in an active seismic zone,” said Honn Kao, an earthquake seismologist with the Geological Survey of Canada, to the Globe and Mail.
Five hours prior to the local earthquake, another two small quakes were reported in California, registering 4.9 and 4.3 respectively. One aftershock was detected after the second earthquake. A few days later, on January 1, another magnitude-4.5 earthquake was felt in Northern California.