Earthquakes not related, says seismologist

  • Apr. 28, 2014 3:00 p.m.

By Jane Wilson–A magnitude 4.2 earthquake hit south of Queen Charlotte last Thursday (Apr. 23), while a 6.6 shook northern Vancouver Island the previous day. The events were unlikely to be related however, according to Dr. John Cassidy, seismologist with Natural Resources Canada. “We don’t think so,” he said, “We’re quite a young science, but they’re very different fault systems.”The Vancouver Island earthquake was a horizontal slipping in the Nootka Fault Zone, which is not one fault, but a broad zone of seismic activity, said Dr. Cassidy. The 2012 Haida Gwaii earthquake was a subduction event in a new fault dipping towards the islands.The 4.2 on Thursday was likely an aftershock from the 2012 earthquake, said Dr. Cassidy. There are still almost daily aftershocks being recorded but most are not felt as they as are smaller than magnitude 3. Thursday’s earthquake was felt by quite a few people in Port Clements, Tlell and Queen Charlotte, he said, because it was a little closer than the other earthquakes, just along the coastline south of QC.The small earthquakes do not reduce the chances of another large earthquake, as they do not release enough energy, said Dr. Cassidy. “Along the coast of BC we can expect a big one at any time.”There is more of a chance of a large earthquake on Moresby Island than on Graham Island because the 1949 earthquake off Graham Island was large enough to have released a significant amount of energy, he said. That earthquake was a magnitude 8.1 and was Canada’s largest recorded earthquake.Dr. Cassidy encourages residents to report earthquakes they feel to the Natural Resources website as it provides valuable information to the researchers. The site can be found at www.earthquakescanada.nrcan.gc.ca/dyfi-lavr/known-connu-eng.php, or by searching “Earthquakes Canada Did you feel it?”More information about recent earthquakes can be found at the Earthquakes Canada site and real time alerts can be found on twitter by following “CanadaQuakes.”

Just Posted

UPDATE: Tsunami warning causes evacuations, closures throughout North Coast

Emergency BC issued the warning after a 7.9 earthquake off Alaska early Tuesday morning

‘The tsunami alarm failed my household’: North Coast residents concerned over sirens, alerts

People living in northern communities share how they learned about Tuesday’s tsunami warning

UPDATE: Tsunami warning cancelled for coastal British Columbia

Warning issued following 7.9 earthquake off Kodiak, AK

Painting her way home

Janine Gibbons talks about all she learned illustrating Haida and Tlingit story books

Haida Gwaii gets top spot in The World

It was already a nice Christmas present, but Keith Moore was really… Continue reading

Tsunami warnings 101: Canada

Here are some things to know about tsunami alerts in Canada and how they work

B.C. Liberals get one last prime-time pitch

Leadership campaign to be decided in Feb. 3 vote

Andrew Scheer on trade, Trump and Trudeau

Canada’s Conservative leader begins three-day visit to B.C.

Victims restrained, sex toys and cash stolen from B.C. adult store

Armed suspects sought in adult store robbery

Vancouver Islanders ponder need for tsunami siren song

Alarm sounds in Port Alberni but not at the DND base in Esquimalt

Babcock, Goyette and Smyth honoured at Order of Hockey in Canada

Mike Babcock, from Saskatoon, guided the Detroit Red Wings to a Stanley Cup in 2008

Bell Canada alert prompts RCMP, privacy watchdog to probe data breach

Company spokesman: ‘Fewer than 100,000 customers were affected’

Snowboarder dies at Vancouver Island ski resort

Death at Mount Washington Alpine Resort

Man faces 48 charges in string of random Toronto shootings

The string of unprovoked shootings began Jan.9, say police

Most Read