'Swarm of earthquakes' rattle off B.C.'s coast, no tsunami expected

Multiple earthquakes were recorded off B.C.'s coast Thursday morning, but no tsunami is expected.

The first happened shortly after 8 a.m. and was measured at 6.4 magnitude, according to the U.S. Geological Survey and Earthquakes Canada. Initially, the quake was reported by USGS as 6.6 magnitude, but it was later downgraded.

USGS said it happened about 209 kilometres away from Tofino.

According to Emergency Info BC, that first earthquake was "lightly felt" near Port Alice.

Earthquakes Canada says another earthquake happened less than 30 minutes later, about 194 kilometres southwest of Port Alice. The agency measured that earthquake as 4.3 magnitude.

"We are currently experiencing a swarm of earthquakes offshore Vancouver Island, at the intersection of the northern Juan de Fuca Ridge, Sovanco Fracture Zone, and Nootka Fault Zone," an alert from Earthquakes Canada shared Thursday morning said.

Just after 9:15 a.m., USGS reported yet another earthquake, this time measured at 5.4 magnitude about 150 kilometres west of Tofino. Meanwhile, Earthquakes Canada recorded that incident as 4.9 magnitude.

Then, at about 10:30, a fourth earthquake was registered measuring 4.8 magnitude, according the Canadian agency.

Emergency Info BC said there was no tsunami threat to the West Coast as a result of the quakes.

At an unrelated news conference, Minister of Emergency Management and Climate Readiness Bowinn Ma said Thursday said the provincial government monitors all earthquake activity, especially off the coast of the province. Ma said of the thousands of earthquakes that are recorded in Canada each year, the "vast majority of them are right here in British Columbia."

"It is an important reminder, however, to all British Columbians who are in a potential earthquake zone to be prepared," she said. "It is important to have that emergency kit at home. Have your emergency grab-and-go bag. Have an emergency plan ready for you and your family."

Ian Cunnings, senior director of response operations for the ministry, said Thursday's seismic activity is "quite common in this area."

"These swarm type of events can really last for one to two weeks," he said. "There is no risk to British Columbians at this time."

Last week, another cluster of earthquakes was recorded off the west coast of Vancouver Island, varying in intensity up to 5.7 magnitude recorded on July 4. Those tremors were all clustered in an area approximately 150 to 250 kilometres from Tofino.

Andrew Schaeffer, an earthquake seismologist with the Geological Survey of Canada, said last week that despite the uptick in seismic activity, the quakes were "business as usual" for the region.

"These are spreading ridge earthquakes, with historical magnitudes up to about 6, but 4s and 5s are relatively common," he said in an emailed statement to CTV News.

"Due to the type of earthquake, these do not typically produce any sort of tsunami, nor would we expect them to be felt, let alone cause damage, on Vancouver Island." 

With files from CTV News Vancouver's Todd Coyne