Seismologists state that the series of earthquakes felt off the coast of B.C. recently are not connected to the subduction zone where the “big One is expected to hit. (File photo)

Run of earthquakes off Vancouver Island not connected to the Big One

Recent tremors not adding or lessening stress on the danger zone

The series of earthquakes that have rattled parts of Vancouver Island recently are not a prelude to the long-expected “Big One” that seismologists have predicted for years.

Seismologist John Cassidy, who works in the Sidney office of Natural Resources Canada, said the entire west coast is an active region of plate tectonics.

He said the six earthquakes that have hit off the Island’s west coast in recent weeks did not originate in the major subduction zone where the Juan de Fuca tectonic plate meets the North American plate.

That’s where an expected major earthquake that could be 9.0 in magnitude on the richter scale or higher (a.k.a the Big One) is expected to originate.

“These earthquakes are not related to that, and they are not adding or lessening the stress that has built up in the subduction zone,” Cassidy said.

“The recent earthquakes were in fairly close proximity to each other and were located in areas where smaller tectonic plates are sliding past each other. Earthquakes from the subduction zone where the Juan de Fuca tectonic plate collides directly with the North American plate are the biggest earthquakes that hit this area, but they are also the rarest.”

The latest earthquake, which struck on Halloween night about 200 kilometres west of Port Hardy at a depth of 10 kilometres, measured 4.9 magnitude.

RELATED STORY: MINOR EARTHQUAKE RECORDED OFF COAST OF VANCOUVER ISLAND

It came on the heels of three relatively strong earthquakes, followed by two smaller ones, last month that were recorded off Vancouver Island, about 260 kilometres west of Tofino.

Those earthquakes ranged from 6.8 to 4.0 on the richter scale, but did not cause damage or a tsunami.

RELATED STORY: THREE STRONG EARTHQUAKES REPORTED OFF VANCOUVER ISLAND

Cassidy said the earthquake on Halloween night was an aftershock from the previous earthquakes. More are likely, but it’s expected they will become less frequent and intense over time.

“We’re not overly concerned about these series of earthquakes, but people should be aware that this is a seismically active region where earthquakes can be expected, including the Big One at some point,” he said.

British Columbia is located on the Pacific Ring of Fire, an active seismic zone where thousands of mostly small earthquakes are recorded annually by sensors in the province.

The last notable earthquake felt by Islanders was on Dec. 30, 2015, when a 4.3-magnitude earthquake, centred approximately eight kilometres east of Sidney, between Victoria and Vancouver, shook Vancouver Island. The last time there was a significant earthquake nearby was a 6.8 magnitude shaker in 2001, which was centred south of Seattle.

The last massive earthquake that was centred in the major subduction zone where the Big One is expected took place on Jan. 26, 1700 and it was estimated to be more than 9.0 magnitude.

It’s estimated that a major quake happens in that region on average every 300 years.



robert.barron@cowichanvalleycitizen.com

Like us on Facebook and follow us on Twitter

Just Posted

First Nations leader to try for NDP nomination in Nanaimo-Ladysmith

Bob Chamberlin, vice-president of Union of B.C. Indian Chiefs, announces intentions

LETTER TO THE EDITOR: Anti-masculinity flourishing

Letter writer concerned with anti-masculinity ideologies in schools and universities

LETTER TO THE EDITOR: SNC-Lavalin case is black and white

The rule of law is a fundamental principle in Canada’s constitution, says letter writer

Man sentenced for tying up, assaulting and robbing another man at Nanaimo hotel

Gabriel Stephen Nelson robbed and assaulted travelling businessman in 2017

Scientists disembark in Nanaimo after international expedition probes Pacific salmon

Canadian, American, Russian, Korean and Japanese scientists survey salmon in Gulf of Alaska

Scientists disembark in Nanaimo after international expedition probes Pacific salmon

Canadian, American, Russian, Korean and Japanese scientists survey salmon in Gulf of Alaska

Canucks hang on for 7-4 win over Senators

Horvat nets 2 for Vancouver

Realtor from Nanaimo named president of real estate board

Kaye Broens becomes president of Vancouver Island Real Estate Board

European, Canadian regulators to do own review of Boeing jet

Air Canada plans to remove the Boeing 737 Max from its schedule at least through July 1

Prime minister defends Liberal budget measures as sales effort gets underway

Conservatives under Andrew Scheer say it’s a spree funded by borrowing against the future

Mayor meets with B.C. health minister on homeless taxi transfers

Two homeless people were discharged from Surrey Memorial and sent to a Chilliwack shelter

B.C. lottery winner being sued by co-workers

They claim he owes them $200,000 each, in a lawsuit filed in B.C. Supreme Court in Vancouver

Teacher reprimanded for conduct towards special needs student

Alan Stephen Berry told vice principal he did not have time to use positive strategies

‘Full worm super moon’ to illuminate B.C. skies on first day of spring

Spring has sprung, a moon named in honour of thawing soil marks final super moon until 2020

Most Read