In The News

Magnitude 4.8 earthquake near Tofino, B.C., rattles houses

Vancouver Island residents reported houses rattling after an earthquake struck shortly after 6 p.m. PT Wednesday.

The 4.8 magnitude quake hit 18 kilometres east-northeast of Tofino, B.C., at a depth of 24 kilometres.

A tsunami is not expected and there were no reports of damage.

Residents in Courtenay, Campbell River and Qualicum Beach reported beds shaking and dishes rattling in their cupboards.

“Staying in a log cabin in Tofino and we thought a truck had hit something,” tweeted one resident.

Hayes Bishop, who works at Middle Beach Lodge in Tofino, said the shaking lasted for about 20 seconds.

“I felt some vibrations and I looked up and I was able to see the window shaking,” he said. “Yeah, you could definitely feel it.”

“Quite a few of the guests came downstairs to ask if that was indeed an earthquake, and there is definitely some cause for concern because we are very close to the ocean here.”

The quake was also felt in the Gulf Islands and as far away as the Lower Mainland, according to some reports.

Earthquake latest in a series

Wednesday’s shaker is the latest in a series of recent quakes that have struck off the B.C. coast.

Last Friday and Saturday separate earthquakes with respective magnitudes of 5.2 and 4.5 struck 200 km off the coast of Port Hardy at the northern end of Vancouver Island.

A swarm of five earthquakes also struck west of Port Hardy further in late December, at depths ranging from 10 to 22 km.

According to the Geological Survey of Canada, these clusters are larger than normal, but not unusual, nor does it effectively increase the risk of the “big one.”

CBC meteorologist Johanna Wagstaffe said Wednesday night’s quake likely occurred within the overriding North America plate.

The smaller quakes can sometimes be damaging because of the shallow depth, she said, even though the recent ones in the past month haven’t fit that characterization.

Wagstaffe said the “big one,” a damaging megathrust earthquake, will occur within the Juan de Fuca plate which has become stuck trying to move under the North American plate. She said these are at two very different locations.

Source: http://www.cbc.ca/news/canada/british-columbia/magnitude-4-8-earthquake-near-tofino-b-c-rattles-houses-1.2893418

4.5 magnitude earthquake reported off B.C. coast

VANCOUVER – A 4.5 magnitude earthquake has struck 208 kilometres west of the northern tip of Vancouver Island.

The federal agency that monitors earthquakes in Canada says no damage or tsunami was expected nor were tremors felt as a result of the event west of Port Hardy, B.C.

A 5.4 magnitude earthquake struck 211 kilometres west of the Vancouver Island community on Friday and was slightly felt in the city of Campbell River and the Metro Vancouver city of New Westminster.

A 4.3 magnitude earthquake struck 517 kilometres northwest of Vancouver Island last weekend.

Earthquakes Canada reported five earthquakes off B.C.’s coast the weekend of Dec. 20 and Dec. 21.

Earthquakes are common off the B.C. coast, where the Juan de Fuca tectonic plate meets the Pacific tectonic plate, but few are large enough to be felt by people.

Source: http://globalnews.ca/news/1754035/4-5-magnitude-earthquake-reported-off-b-c-coast/

5.4 magnitude earthquake hits off coast of Vancouver Island

VANCOUVER – A 5.4 magnitude earthquake struck off the coast of Vancouver Island on Friday morning, two weeks after an earthquake hit in almost the same location.

Earthquakes Canada says Friday’s quake hit at 2:15 a.m. off the west coast of the island, on the boundary of the Juan de Fuca plate system and the North America Plate, on the spreading centre. There are no reports of any damage or injuries, but residents of Campbell River, Vancouver and New Westminster may have felt some light shaking.

On Saturday, Dec. 20, a 4.3 magnitude earthquake struck the same region. There was no damage or tsunami from that quake.

Earthquakes Canada has recorded five earthquakes off B.C.’s coast during the weekend of Dec. 20 and Dec. 21, 2014.

“We’ve had a number of earthquakes up there,” said Taimi Mulder, from the Natural Resources Canada, Geological Survey of Canada. “In that area there often, once or twice a year there could be a magnitude 5 there.”

She said this is not unusual activity for that area and there has been a lot of small plate shifting since the Haida Gwaii earthquake in October, 2012. “In the last two, three years it has been a little more active,” said Mulder.

“Five is on the order where you would start to see damage if it was to happen on land.”

Source: http://globalnews.ca/news/1752762/5-4-magnitude-earthquake-hits-off-coast-of-vancouver-island/

Five powerful earthquakes rattle B.C., edges of the Pacific plate over the weekend

A series of five strong earthquakes rattled coastal B.C. this weekend, starting just a few hours before five more — including a magnitude 6.6 quake — hit Indonesia.

The B.C. quakes measured from 4.0 to 5.1 in magnitude and were centred offshore between Haida Gwaii and Vancouver Island, about 200 kilometres southwest of Bella Bella, according to the U.S. Geological Survey.

In all, 15 earthquakes measuring above 4.0 were detected from about 3 p.m. Saturday to 5 p.m. Sunday at spots around the perimeter of the Pacific Plate, which runs along the western edge of North America from the Baja California peninsula to the Aleutian Islands in the north, and south from Russia to New Zealand, via coastal Japan, Indonesia, and the Philippines.

Though some earthquakes are known to trigger others, it is unlikely that happened this weekend, say experts in the field.

“The earth is hugely seismically active,” said Brett Gilley, an instructor with the University of B.C.’s Earth, Ocean and Atmospheric Sciences Department.

He said it is not uncommon for earthquakes to cluster locally as happened in B.C., then Indonesia.

“Earthquakes often happen in swarms,” said Gilley, noting that those off the B.C. coast were of similar size. “What’s happening is the stress is sort of adjusting over the whole area.”

With so-called transform earthquakes, like those that happen along the San Andreas Fault in California, experts can sometimes make a loose prediction that one quake might trigger another nearby, said Gilley. But with subduction zones, like that where the Juan de Fuca plate meets the North American plate, the relationship between one quake and another is harder to predict.

Dan Gibson, an assistant professor in Earth Sciences at Simon Fraser University, said it would take a very large earthquake, in the magnitude of 8 or more, to set off others, though the relationship is still hard to prove or disprove.

He pointed to a unique 8.6 magnitude transform earthquake that happened off the west coast of Sumatra in 2012 that is thought to have triggered other major quakes around the world.

“That was such a big one, and it may have been unique circumstances where there was a slight (lull) in earthquake activity and a bunch of built-up stress along plate boundaries, that it began to trigger other ones,” said Gibson.

“They were ready. They were sort of at a critical state already and then there was just enough energy transmitted … that it caused the other ones to release.”

Earthquake waves can travel the roughly 11,000 kilometres from B.C. to Indonesia in about two hours, said Gibson, but those from a quake of Sunday’s magnitude would be so degraded by the time they arrived they would need to be measured by seismometers.

Brent Ward, an Associate Professor of Earth Sciences at SFU, said a 5.1 quake off the West Coast as happened around 7 p.m. Saturday “is fairly big,” but he didn’t think the shaking at either side of the Pacific was related.

“There’s tens of hundreds of earthquakes every day,” he said, adding that scientists generally “don’t think there’s an association between quakes in far flung areas.”

Source: http://www.vancouversun.com/technology/Five+powerful+earthquakes+rattle+edges+Pacific+plate+over+weekend/10671848/story.html

Earthquake detected off British Columbia

VANCOUVER – There was a 4.3 magnitude earthquake off the coast of B.C. on Saturday afternoon.

The federal agency that monitors earthquakes in Canada says the tremor was centred offshore about 517 kilometres west northwest of Vancouver.

Earthquakes Canada says there are no reports of damage, but none would be expected given the location of the quake.

The earthquake centre says no tsunami would be expected.

Source: http://globalnews.ca/news/1738289/earthquake-detected-off-british-columbia/

Small earthquake strikes B.C. coast off Sechelt

A 3.2-magnitude earthquake that struck off the B.C. coast early Thursday morning may have been felt by some residents on Vancouver Island and in the Gulf Islands.

The small quake was recorded underwater between 17 kilometres west of Sechelt shortly before 7 a.m., according to Natural Resources Canada.

The agency said the quake was “lightly felt” in Powell River, Roberts Creek and Salt Spring Island.

There are no reports of damage, and none are expected.

Source: http://www.vancouversun.com/news/Small+earthquake+strikes+coast+Sechelt/10460283/story.html

Seismic risk rises at some B.C. dams

Six-year BC Hydro study gives better understanding of earthquake impact.

BC Hydro will draw down the water level at an Interior dam and offer to buy 11 homes in the path of a Vancouver Island dam in response to a $10-million study that has better identified major earthquake hazards.

The study, which took six years and involved 25 international experts, used the latest scientific information on earthquakes and applied methods created by the U.S. nuclear industry to determine seismic risks.

The 3,500-page, four-volume report, Probabilistic Seismic Hazard Analysis, determined the hazard from a major earthquake was the same or lower than previously understood at power dams on the Peace River system in northern B.C. and the Columbia River system in the Southern Interior.

But it also found an increase in seismic hazard risks on the Campbell River system and the Jordan River system near Sooke, both on Vancouver Island. The seismic hazard has also increased on the Bridge River system near Lillooet in the Interior.

BC Hydro officials stressed the province’s hydro dams are safe given the new information, but it is important to prepare for the possibility of a major earthquake, the kind that could happen once in 1,000 years.

Officials also said the study will help them better prioritize spending of $1.9 billion earmarked for seismic and safety upgrades in the next decade, $700 million of that targeted for Vancouver Island.

The new information does not affect Hydro’s existing plan for electricity rates to homeowners, businesses and industrial users.

BC Hydro also plans to make a major effort to reach out to the public and First Nations about how to prepare for the consequence of a dam break in the event of a major earthquake, which includes having a plan to get out of the path of the ensuing flood or to high ground. “It’s pretty much a landmark study … It’s excellent, worldleading work. It’s been all scientifically peer-reviewed, poked at and prodded, so we are sure we have the best possible science to support decision making going forward,” said Chris O’Riley, BC Hydro’s executive vice-president of generation.

“We see this as an opportunity to have a larger conversation with the public around emergency preparedness, particularly on Vancouver Island. The seismic risk is real. It’s something we live with every day,” he noted.

The study found the Jordan River system on Vancouver Island near Sooke has the highest seismic hazard in B.C., possibly in Canada.

BC Hydro has concluded it is not feasible to reduce the reservoir level because the water is needed to produce power at peak times for the Victoria area. Nor was it deemed practical to rebuild the dam system, which would cost hundreds of millions of dollars.

That’s why Hydro decided it would offer to buy the 11 homes in the flood path of the dam, to reduce the consequence of a failure, said O’Riley.

The Crown corporation’s plan also includes lowering the maximum reservoir level by 16 metres at the LaJoie dam on the Bridge River system near Lillooet in the Interior. That will take the load off the dam and diminish seismic risks to an acceptable level, said O’Riley.

The lower reservoir level will affect Hydro’s generation capacity, but not significantly.

BC Hydro already has an upgrade plan underway on the Campbell River system, where an increase in seismic hazard was found.

The first stage, which broke ground this fall, is the $1-billion replacement of the John Hart generating station. That project will take three to four years, but will allow the reservoir level to be lowered and more detailed seismic upgrades to take place on the system in the next 10 to 20 years.

The new study allowed BC Hydro officials to decrease the uncertainty of their modelling results and better understand the level of ground motion that would take place at dam sites throughout the province when a major earthquake takes place.

A key finding of the study was that a major earthquake triggered at the Cascadia subduction zone off B.C’s coast – where the ocean plate is pushing underneath North America’s continental plate – will cause longer ground shaking than understood previously.

A 2013 study by Royal Roads University, the Geological Survey of Canada, the University of B.C. and the University of California concluded the Pacific coast has experienced 22 major earthquakes over the past 11,000 years and is due for another.

Researchers said there is evidence the last major earthquake from this zone took place around 1700.

Source: http://www.vancouversun.com/news/Seismic+risk+rises+some+dams/10442377/story.html

Older brick buildings at risk in earthquake, contractor warns

WorkSafeBC should ensure anyone who works in older unreinforced masonry buildings (URMs) in southwestern B.C. knows they’re at considerable risk in the event of an earthquake.

That’s the goal of an application West Vancouver contractor Stephen Noon has made to WorkSafeBC, as he feels local and senior governments have done little to warn workers of the potential hazard.

URMs are brick buildings constructed without steel reinforcements, ties and connections required by modern building codes.

Noon, who specializes in interior renovation work and hopes to import earthquake-resistant desks to B.C., fears there could be thousands of older, earthquake-susceptible buildings in the Lower Mainland and Vancouver Island that would suffer catastrophic damage in a major quake.

“You wouldn’t go into a place with exposed asbestos and this situation (with URMs) is comparable to that,” Noon said. “Asbestos will kill you over a lifetime, but being in the wrong building during an earthquake can kill you instantly.”

Carlos Ventura, director of the Earthquake Engineering Research Facility at the University of B.C., said a California law requires all unreinforced masonry buildings to display signs warning that an earthquake could cause major damage.

“The owners of unreinforced masonry buildings have to make it clear to the tenants that there’s a seismic risk if the building hasn’t been retrofitted,” he said.

Noon feels a WorkSafeBC warning to workers about the hazards of old brick buildings at risk would start the ball rolling on properly dealing with the situation.

“That could start an inventorying system and generally create better public awareness,” he said. “People may decide to lease space in different buildings because the one they’re in just isn’t safe.”

But WorkSafeBC spokesman Scott McCloy said it isn’t his agency’s mandate to deliver such a warning to workers.

“Although we generally expect workplaces to be constructed and maintained in a way that ensures workers’ safety, we don’t directly regulate building codes, which contain seismic provisions enforced by local government,” he said. “Building code standards are regulated through the building code administered by the building and safety standards branch (of the B.C. housing ministry). It’s more their mandate than ours — to directly regulate building codes.”

Warning signs aren’t required in Vancouver but the city requires seismic upgrades when significant changes are made to old brick buildings — including the conversion of many Gastown warehouses into office buildings.

“We still have schools and hospitals with the same type of construction so it’s a concern that not much work has been done in many of these buildings,” Ventura said.

A 1995 City of Vancouver study showed that 1,150 buildings with three or more storeys were built in the city before seismic codes were introduced in 1973. Four hundred of those buildings were found to be at “high” or “very high” risk of collapsing during a major earthquake.

The B.C. government expects to spend $2.8 billion to seismically upgrade or replace 339 schools in the province, but Noon stressed there are major seismic issues at non-school buildings throughout B.C., including the legislature buildings in Victoria.

One report estimates it would cost $250 million to complete a seismic upgrade of the provincial legislature.

“The standards here seem to be behind everyone else,” Noon said. “Even Utah has started URM reduction programs and we have done nothing, apart from the school program.”

Following the deadly 2011 earthquake in Christchurch, the New Zealand government set a 20-year deadline for assessing 193,000 buildings for earthquake risk and then strengthening them. Any building at risk of collapse has to be strengthened or demolished within 15 years.

Seattle officials are establishing a list of URM buildings in their city and will consider a proposal next year that would allow building upgrades to take place over seven to 13 years, based on the building’s risk category.

Noon disagreed with WorksafeBC’s assessment, saying someone has to take responsibility for the issue.

“I think this is just passing the buck,” he said. “It’s clear that WorkSafeBC is liable for injuries and deaths that occur in the workplace and many of those will be caused by these URMs not holding up in an earthquake.”

The provincial ministry responsible for the building and safety standards branch said in a statement that employers on construction sites are responsible for ensuring worker safety.

“WorkSafeBC generally expects workplaces to be constructed and maintained in a manner that ensures worker safety,” the ministry said. “The B.C. Building Code applies during construction, up to the point the building is completed. The provincial government maintains the B.C. Building Code.”

McCloy said WorkSafeBC would usually provide compensation for workers injured during an earthquake.

“While there may be some exceptions, the answer is generally yes,” he said. “Every claim is reviewed based on its individual circumstances.”

WorkSafeBC has established a $20-million Earthquake Disaster Reserve to provide for claims from workers injured during an earthquake disaster.

Source: http://www.vancouversun.com/business/Older+brick+buildings+risk+earthquake+contractor+warns/10417561/story.html

$66M earthquake-proof upgrades urged for Parliament Hill’s East Block

Building is ‘unlikely to meet 60 per cent of the seismic design requirement,’ report says.

Parliament Hill’s oldest building, an architectural gem known as the East Block, is vulnerable to the frequent earthquakes of the Ottawa area and needs at least $66 million in upgrades to make it more tremor-resistant.

Even with that minimum hardening of the walls and towers, the East Block will still be only 60 per cent as resistant to quakes as Canada’s national building code requires for all modern buildings.

Those are the findings of a series of reports commissioned by Public Works in the wake of three major earthquakes that rattled the capital in 2010 and 2012 and set the Peace Tower and a main tower on the East Block swaying back and forth. CBC News obtained copies of the internal reports under the Access to Information Act.

“The advanced deterioration of the exterior masonry walls has been a concern for many years,” says one report.

“The East Block building is unlikely to meet 60 per cent of the seismic design requirement of the (National Building Code of Canada) and will need to be upgraded.”

“The review of the building envelop investigation and screening reports has revealed significant and serious deterioration of the exterior masonry walls. Low strength lime mortar or totally degraded lime mortar was observed in numerous locations …”

Public Works is in the midst of a multibillion-dollar refurbishment of the three main structures on Parliament Hill, with the West Block well under way and the East Block next in line before workers begin a massive renovation of the Centre Block, home to the House of Commons and Senate.

Seismographs placed in the towers of these three buildings recorded the impact of relatively large earthquakes in recent years; that is, the magnitude 5.0 “Val-des-Bois” earthquake of June 23, 2010, the 4.5 magnitude “Saint-Hyacinthe” quake on Oct.10, 2012; and the 4.2 magnitude “Buckingham” quake of Nov. 6 that same year.

Towers swayed during recent earthquakes

The Peace Tower showed “strong motion” for all the events, while the southwest tower of the East Block swayed in an east-west direction during two of the quakes.

Other reports for Public Works between 2011 and 2013 investigated the crumbling masonry of the East Block walls, some of which date back to 1859 when construction began.

Public Works’ policy on heritage buildings such as the East Block is to bring them up to between 60 per cent and 100 per cent of the national building code’s standards for seismic resistance, while preserving their character. Experts have recommended the 60 per cent mark for the Gothic Revival structure, which appears to be the most vulnerable of the Parliament Hill buildings to earthquakes because of its much greater age.

Steel cable held tower together

Public Works has already undertaken a $14.1-million pilot project on one of the East Block’s towers, at the northwest, which included seismic upgrading to develop possible solutions for the rest of the building. The two-year upgrade was finished in the fall of 2013. Until then, the tower had been held together with steel-cable strapping to prevent collapse.

A 2012 estimate provided by the consultant firm Hanscomb Ltd. says upgrading the rest of the East Block to at least 60 per cent of the national building code requirements for quake-resistance will cost $65.8 million.

Hanscomb also estimated the cost for making the East Block resistant to a blast, such as produced by a bomb, but all references are blacked out in the document under security exemptions in the Access to Information Act.

Public Works, meanwhile, hired the Montreal firm Arcop Architecture Inc. in July to make its own determination of the seismic upgrades needed, as well as other improvements.

“The prime consultant is reviewing the preliminary findings contained in the (Hanscomb) report, and must then conduct further analysis and on-site investigations to finalize the seismic rehabilitation of the building,” said Public Works spokeswoman Annie Joannette.

The exterior of the oldest part of the East Block is scheduled for $167 million in upgrades between 2016 and 2022, but interior seismic hardening is still in the planning stages, as are upgrades to a 1910 addition to the building.

Seismic standards in Canada’s building code are intended to allow the safe evacuation of people inside older buildings in the event of a major earthquake.

Buildings safe: Public Works

Joannette said that “all reports to date have determined that the buildings are safe to be occupied. The East Block is safe and was not damaged during recent earthquakes.”

Barry Padolsky, an architect who recently worked on upgrading Ottawa’s historic Museum of Nature to modern seismic standards, said similar challenges await the team that will upgrade the East Block.

“They will face a similar challenge, as do all heritage buildings, and the challenge not just technically how to do it but to make sure that you don’t harm the building while you are installing it,” he said in an interview.
“There is no question that these things have to be done because the Museum of Nature, Parliament Hill and other historic buildings in the capital are part of our heritage and we would never be forgiven if we didn’t protect them.”

The Centre Block’s seismic upgrades, including to the Peace Tower, are scheduled as part of the major rehabilitation set to begin in 2018, after the Commons and Senate chambers have been temporarily moved to new locations.

Canada has two major earthquake zones, southwestern British Columbia and the Ottawa and St. Lawrence River valleys, including Ottawa, Montreal and Quebec City.

An October 2013 study commissioned by the Insurance Bureau of Canada estimated there is at least a five-to-15 per cent chance that an earthquake capable of significant damage will strike the southern Quebec and southeastern Ontario area in the next 50 years.

The study said unreinforced masonry buildings, such as that of the East Block and many historic buildings in Quebec City, are particularly at risk. A large quake could cost $60 billion in damage, mostly to shattered buildings.

Source: http://www.cbc.ca/news/politics/66m-earthquake-proof-upgrades-urged-for-parliament-hill-s-east-block-1.2834334