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6.4M quake that struck off B.C. is part of recent ‘swarm’

13 quakes greater than around 4.0M detected in July in same area off Vancouver Island, Earthquakes Canada says

A series of four earthquakes, including one with a preliminary magnitude of 6.4, struck off the coast of Vancouver Island on Thursday morning, part of an ongoing “swarm” of quakes being detected off the British Columbia coast.

The first and largest quake occurred at 8:08 a.m. PT at a depth of 10 kilometres, 183 kilometres southwest of Port Alice, B.C., according to Earthquakes Canada.

The agency said no tsunami and no damage was expected, but the earthquake might have been felt by some residents of Vancouver Island.

The 6.4-magnitude quake was followed by one preliminarily measured at 4.3 magnitude at 8:35 a.m. PT, another at 4.9 magnitude at 9:17 a.m. PT, and yet another preliminarily measured at 4.8 magnitude at 10:34 a.m. PT, all near the same location.

A total of 13 earthquakes with a preliminary magnitude of around 4.0 or greater have now been detected in B.C. waters since the start of July.

A notice posted to the Earthquakes Canada website says the agency is tracking a “swarm of earthquakes offshore Vancouver Island, at the intersection of the northern Juan de Fuca Ridge, Sovanco Fracture Zone and Nootka Fault Zone.”

Natural Resources Canada seismologist John Cassidy described the region as a “really complicated tectonic setting,” in an interview with CBC News in Victoria after the earthquakes hit.

“We have plates moving apart, sliding past one another and we have, in fact, three major fault systems that intersect in the vicinity of these earthquakes,” he said. “Going back as long as we’ve been recording earthquakes, it’s one of the most active zones in Canada.”

He said while there is no reason to be concerned about the current cluster of quakes posing a risk to safety given their depth and distance from land, they do serve as a reminder that B.C.’s coast is susceptible if and when an earthquake strikes closer to the shore.

“This sequence doesn’t tell us when a large earthquake will happen closer to land, but it does remind us that we live in a very active zone,” Cassidy said.

The current quakes also give scientists useful data to help better predict and understand future rumblings, he added.

“This earthquake … will be very useful for us in terms of understanding what we can expect from future events,” he said.

See more at CBC: https://www.cbc.ca/news/canada/british-columbia/earthquakes-vancouver-island-1.7260618

New research highlights where ‘The Big One’ earthquake could hit

Northern part of the long Pacific Ocean fault most likely to produce a major earthquake, scientists say

New research offers a clearer picture of a fault line hundreds of kilometres long off the West Coast that is predicted to generate a major earthquake and tsunami commonly known as “The Big One.”

The study confirms that the northern part of the fault, close to Vancouver Island and Washington state, is most likely to produce a major earthquake. 

“It’s giving us the first really detailed look at this huge megathrust fault that we’ve long known about but haven’t had any details about,” Edwin Nissen, a University of Victoria earth and ocean science researcher who was not involved in the research into the fault line where two tectonic plates meet.

The research, recently published in the prestigious journal Science Advances, produced the most detailed picture researchers have yet had of the fault zone spanning more than 900 kilometres from northern California to Vancouver Island — imaging they say helps them understand the magnitude and probability of earthquakes.

See more at CBC: https://cbc.ca/news/canada/british-columbia/cascadia-subduction-zone-imaging-1.7235949

4.4 Magnitude Earthquake Hits Southwest of Prince Rupert, B.C.

The early-morning quake did not generate a tsunami threat, nor were there any reports of damage or injuries.

An earthquake struck off the British Columbia coast early Tuesday morning, registering as a 4.4 magnitude quake, according to the United States Geological Survey (USGS).

The tremor occurred 215 kilometres south-southwest of Prince Rupert, B.C., at a depth of 18 km.

See more at The Weather Network: https://www.theweathernetwork.com/en/news/weather/severe/earthquake-hits-southwest-of-prince-rupert-b-c

Earthquake in Turkey underscores risks and responsibilities for British Columbians

Similarities and differences in Turkey quake and what’s expected in B.C.

The devastating earthquake and aftershocks that rocked southeastern Turkey and northern Syria Monday has, for many, underlined the risks and dangers of a major earthquake hitting British Columbia.

The 7.8-magnitude earthquake toppled hundreds of buildings and killed thousands of people, the toll expected to rise as rescue workers search mounds of wreckage in cities and towns across the area.

Turkey sits on top of two major fault lines and frequently experiences earthquakes, although Monday’s was one of the biggest in at least a century.

CBC seismologist Johanna Wagstaffe says Monday’s massive quake happened after two tectonic plates became locked.

 “That’s an area of the world where we have seismic gaps,” said Wagstaffe. “Basically, where we know we have locked sections of big faults that are waiting to go.”

She says there are similarities and differences in the type of earthquakes that struck Turkey and northern Syria — and the type expected to hit British Columbia.

“It’s the fact that we, too, are in this seismic gap,” Wagstaffe explained. “The Cascadia subduction zone off the coast of Vancouver Island is an area where two plates have become locked.”

The Cascadia subduction zone is a 1,000-kilometre fault that runs from northern Vancouver Island to northern California. The fault itself is a boundary between two tectonic plates: the Juan de Fuca and the North American plate.

The Juan de Fuca tectonic plate is being forced underneath the North American plate. The energy from that movement is being stored up inside the rocks, waiting for the moment it will be released as a catastrophic megathrust earthquake — also known as “The Big One.”

Turkey’s earthquake was due to a transform fault, or side-to-side quake, where two tectonic plates slide past each other horizontally.

See more at CBC News: https://www.cbc.ca/news/canada/british-columbia/earthquake-in-turkey-underscores-risks-and-responsibilities-for-british-columbians-1.6738696

B.C. experienced close to 2,500 earthquakes in 2022

B.C. is the most seismically active area of Canada, according to ShakeOut B.C., an emergency preparedness organization.

Canada’s second largest earthquake in 2022 occurred in B.C., a 5.3 magnitude quake off the northwest coast of Vancouver Island. 

The largest, a magnitude 5.5, happened in Yukon, just across the border from B.C. and Alaska.

They were two of the roughly 2,500 earthquakes to shake the province last year, most of which occurred in the ocean off the west coast of Vancouver Island and Haida Gwaii.

“It’s not unusual to see a magnitude 5 1/2 or six as the largest earthquake of the year,” said John Cassidy, head of the earthquake seismology section of the Geological Survey of Canada. “Some years we see much larger than that.”

Cassidy called 2022 “pretty typical” for earthquakes in B.C., which experiences thousands of earthquakes a year. B.C. is the most seismically active area of Canada, according to ShakeOut B.C., an emergency preparedness organization.

B.C.’s five largest earthquakes last year were all between magnitude five and 5.5. Earthquakes below magnitude 5.5 rarely cause damage.

The largest earthquake in modern B.C. history was a magnitude 8.0 quake that took place in Haida Gwaii on Aug. 22, 1949.

Cassidy said that while it is not currently possible to predict earthquakes, the field has changed significantly in the past decade, including improvements in data collection, data quality and computing.

He pointed to a joint project between Canada, the U.S., Germany and Japan that recently mapped the sea floor off the coast “in detail that we’ve never had before.”

“We do have more data, we have more instruments on the ground. So we’re getting better recordings and better information that really allows us to improve our seismic hazard models,” he said.

Two projects that should come online in about a year will offer significant improvements in earthquake warning and safety.

The first, an early warning network that is currently being set up, is scheduled to be in full operation “in just over a year,” Cassidy said.

“It’s providing seconds or tens of seconds or maybe even a few minutes of warning before strong shaking arises,” he said. “That’s been used in many parts of the world.”

The second is a network of what Cassidy called “strong motion” sensors, which are designed to record very large earthquakes — the kind with shaking strong enough to “toss furniture around and lift people off their feet.”

“We don’t have Canadian data on strong shaking,” Cassidy said, calling it the “most important” data for engineers who design building codes for seismic safety.

“What we’re currently doing in our national building code is we use recordings of strong earthquakes from other parts of the world that are similar to Canada,” he said. “So if you’re in British Columbia, we look at data from Japan or data from New Zealand, where there have recently been some strong earthquakes.”

The current network of seismic sensors in Canada record small earthquakes that would be overwhelmed by a very large earthquake, he said.

“The new instruments that are being deployed will actually be able to record those strong shaking events,” said Cassidy.

Ultimately, being prepared and having solid building codes may be the most reliable protection against earthquakes. Simple steps like having a flashlight or headlamp in easy reach if power goes out and practicing the drop, cover and hold on drill can make all the difference in an emergency.

“If you’ve designed your structures and people are prepared and know what to do, then the timing (of earthquakes) is not so important,” Cassidy said.

See more at The Vancouver Sun: https://vancouversun.com/news/local-news/bc-earthquakes-2002

4.6-magnitude earthquake shakes near Vancouver Island

No tsunami is expected after a 4.6-magnitude earthquake was recorded off Vancouver Island on Tuesday.

Earthquakes Canada says the shaking was detected at 5:29 a.m. PT and no damage was reported.

The earthquake was centred approximately 210 kilometres west of Port Hardy, B.C., near the northern tip of Vancouver Island. It was measured at a depth of 10 kilometres.

The earthquake was at least the third seismic event to register in the region over the past two weeks, following a 4.8-magnitude quake on Nov. 26 and a 4.0-magnitude quake on Nov. 24.

The Nov. 26 quake was felt by many in the region, including former Tofino mayor and current Mid Island-Pacific Rim MLA Josie Osborne, who said on Twitter that her “whole house shuddered,” and reminded residents to be prepared.

Tuesday’s earthquake comes 104 years to the day since a 7.0-magnitude earthquake struck west of Vancouver Island.

The large quake occurred just after midnight on Dec. 6, 1918, and awakened people all over Vancouver Island and Metro Vancouver, according to Earthquakes Canada.

The agency says the historic quake caused some localized damage to the Estevan Point lighthouse and to a wharf in Ucluelet, B.C.. It was felt as far south as Washington state and as far east as Kelowna.

See more at CTV News: https://vancouverisland.ctvnews.ca/4-6-magnitude-earthquake-shakes-near-vancouver-island-1.6182768

Significant back-to-back earthquakes in northern B.C. ‘very likely’ caused by fracking

4.6 and 4.7 magnitude quakes northwest of Fort St. John recorded within four days, just a kilometre apart.

Two significant earthquakes within a week in northeast B.C. were probably triggered by hydraulic fracturing, or fracking, according to preliminary information from federal scientists. 

On Nov. 11, Earthquakes Canada reported a 4.7-magnitude earthquake, 132 kilometres northwest of Fort St. John.

That was followed four days later by a 4.6-magnitude quake recorded just a kilometre away from the first seismic event.

“There is an active hydraulic fracturing operation nearby,” said Prof. Honn Kao, a research scientist with the Geological Survey of Canada. “The likelihood of these two events being induced by industry is very high.”

Earthquakes Canada said while the tremors were “lightly felt in the surrounding area,” there were no reports of damage.

Fracking involves injecting fluids into a deep well under high pressure to fracture tight rock formations and release the natural gas inside. 

According to the B.C. Oil and Gas Commission (BCOGC), the province’s energy regulator, fracking in B.C. takes place deeper underground than it does in other areas of the world — sometimes more than four kilometres beneath the surface. 

In an email to CBC News, the BCOGC said all drilling in the Montney formation near Fort St John B.C., “has or will eventually involve hydraulic fracturing operations.” 

According to information on the BCOGC’s website, “microseismic events” occur when fluid fractures the rock.

“In some cases, where there is a susceptible pre-existing fault, slippage on the fault plane can occur,” it says.

While the vast majority of fracking operations don’t trigger earthquakes,the practice has been linked to most of the larger seismic events in Alberta and northeastern B.C. over the past decade.

See more at CBC News: https://www.cbc.ca/news/canada/british-columbia/northern-bc-fracking-earthquakes-november-2022-1.6654969

Lack of funding for new B.C. schools, seismic upgrades has critics questioning priorities

Parents, school boards unimpressed with project delays, as NDP defends $800M seismically safe museum project

The British Columbia government is ending the academic year on the defensive after several school districts were told they would not be receiving any new money for much-needed infrastructure projects.

School districts in Vancouver, Mission, Greater Victoria, the Kootenays and Maple Ridge-Pitt Meadows all recently learned their requests for capital funding had been denied by the Ministry of Education. The money had been requested to build new schools and seismically upgrade buildings at risk of collapsing in an earthquake.

At the same time, critics are highlighting the B.C. NDP’s recent announcement of an almost $800 million seismically safe rebuild of the Royal B.C. Museum in Victoria. While the government insists the museum investment has not pulled money from school project funding, the optics are not sitting well with parents, school boards and opposition parties.

“To spend a billion dollars for a brand new Royal B.C. Museum that nobody wanted, while halting construction on already announced schools that parents and teachers were promised, is unacceptable,” said B.C. Liberal Leader Kevin Falcon in a statement.

Falcon says Premier John Horgan is using costs associated with last year’s fires and floods as an excuse to freeze school spending despite forging ahead with a “boondoggle museum project.”

Green Party Leader Sonia Furstenau said families are being let down by the government’s spending priorities.

But the provincial government rejects these claims.

See more at CBC: https://www.cbc.ca/news/canada/british-columbia/stalled-school-projects-1.6484559

Engaging communities with Canada’s earthquake early warning system

For residents of British Columbia, along the west coast of Canada, seeing a road sign that says, ‘Entering Tsunami Hazard Zone’ is a common occurrence. The sign reminds travelers that British Columbia and much of western North America is earthquake country.

Here, the Juan de Fuca tectonic plate is diving under the North American plate. This boundary, called the Cascadia Subduction Zone, extending from British Columbia down to northern California, has the potential to generate very large magnitude earthquakes and tsunamis and is currently primed for the next one.

Ensuring Canadians are alerted of potentially harmful earthquakes in the region falls to Natural Resources Canada (NRCan), a federal organization tasked with developing policies and programs to utilize the country’s natural resources. Wednesday, at the American Geophysical Union Annual Meeting, a team of researchers at NRCan provided an update on Canada’s planned earthquake early warning system and discussed their efforts to engage the public.

See more at Temblor: https://temblor.net/earthquake-insights/engaging-communities-with-canadas-earthquake-early-warning-system-13556/

No tsunami threat to B.C. after powerful M8.2 earthquake shakes Alaska

Quake that struck on Wednesday night was the most powerful recorded in U.S. or Canada since 1965: USGS data

A powerful earthquake that struck just off Alaska’s southern coast caused prolonged shaking and prompted tsunami warnings that sent people scrambling for shelters.

The U.S. Geological Survey (USGS) said the quake measured magnitude 8.2 and hit 91 kilometres east southeast of Perryville, Alaska, at about 8:15 p.m. PT Wednesday. It struck about 46 kilometres below the surface of the ocean, according to USGS.

It was one of the most powerful quakes in U.S. and Canadian recorded history, and the largest since 1965, according to USGS data.

Residents reported only minor damage, but officials said that could change after sunrise and people get a better look.

People living in coastal areas of British Columbia waited anxiously past midnight as emergency officials evaluated the local tsunami risk. After more than three hours, officials confirmed there was no threat to the province just after 2:30 a.m. PT.

Roughly 800 people from Kitamaat Village, south of Kitimat, B.C., moved to higher ground as a precaution.

“My daughter woke us up and said that our emergency crew was going around the streets telling everybody to get to higher ground. So in a stupor, I helped get my family out the door,” Skeena MLA Ellis Ross told CBC’s Daybreak North on Thursday.

“My adrenalin was pumping so hard. I was on top of the hill directing traffic, trying to keep people moving, keep people calm,” added Ross, who helped develop the community’s emergency plan as chief councillor of the Haisla Nation.

“It was not much time to think about anything, really, except getting people to a certain place safely.”

The National Tsunami Warning Center cancelled warnings early Thursday when the biggest wave, of just over a half foot, was recorded in Old Harbor, Alaska. A tsunami warning that had been issued for Hawaii was also cancelled, and officials said there was no threat to Guam, American Samoa or the Commonwealth of Northern Mariana Islands.

The warning for Alaska covered nearly a 1,600-kilometre stretch from Prince William Sound to Samalga Island, near the end of the Aleutian Islands.

Patrick Mayer, the superintendent of schools for the Aleutians East Borough, was sitting in his kitchen in the community of Sand Point when shaking from the quake started.

“It started to go and just didn’t stop,” Mayer told the Anchorage Daily News. “It went on for a long time and there were several aftershocks, too. The pantry is empty all over the floor, the fridge is empty all over the floor.”

On the Kenai Peninsula, a steady stream of cars were seen evacuating the Homer Spit, a jut of land extending nearly eight kilometres into Kachemak Bay that is a draw for tourists and fishermen.

In King Cove, up to 400 people took shelter in the school gym.

”We’re used to this. This is pretty normal for this area to get these kind of quakes, and when the tsunami sirens go off, it’s just something we do,” school principal Paul Barker told the Anchorage newspaper.

“It’s not something you ever get used to, but it’s part of the job living here and being part of the community.”

Several other earthquakes, some with with preliminary magnitudes of 6.2 and 5.6, occurred in the same area within hours of the first one, USGS reported.

Source: https://www.cbc.ca/news/canada/british-columbia/alaska-earthquake-no-tsunami-threat-to-bc-1.6122218