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No B.C. earthquake in the forecast

Recent earthquakes around the world a ‘coincidence’
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On March 9, the Washington Post ran a question and answer article titled "Seismic Science: Is number of earthquakes on the rise?" which stated that the number of earthquakes reported is still within averages, but that various considerations like population movement and media coverage made them appear worse.

Later that day an earthquake measuring about 6.9 on the Richter scale hit Chile, just weeks after the country was rocked by an 8.8 quake and tsunami that left hundreds dead and thousands homeless.

Both came on the heels of large quakes off the coast of Japan and a massive quake in Haiti in early January that killed an estimated 230,000 people and left millions homeless.

Earthquakes are very much in the news and on everyone's mind these days, and for residents of B.C. - who have been warned their whole lives that "the big one" is just around the corner - the question is whether these big quakes off the coast of Chile and Haiti are a sign of bigger things to come.

Alison Bird, an earthquake seismologist for Natural Resources Canada, reassures that the recent quakes are not related to one another and can't trigger a quake off the coast of B.C. - that's not to say that it can't happen at any time, just that one quake doesn't cause another.

"We're not seeing any elevated activity within Canada," she said. "They're not related, the earthquakes in Haiti and Chile, and we haven't seen any related activity up here. When events happen like that in a short period of time it's really just the luck of the draw, it's a coincidence that they happened so close together.

"It's hard to convince people of that, but it's not like a domino effect."

As for the theory that earthquakes are affecting more people than before, Bird says that is very much the case with western North America.

"People tend to want to live in attractive areas, and they're usually attractive because of tectonics," she said. "The tectonics of our region caused our mountains and our beautiful landscapes. Also, people tend to live on coasts no matter where you are, and that's where most of the plate boundaries are."

That said, B.C. will always be a hot spot for earthquakes, with an average of over 1,500 quakes a year.

There is a potential, says Bird, of a large quake of 9.0 where the Cascadian Subduction Zone meets the North American Plate, about 150 km off the west coast of Vancouver Island. An event of that magnitude would leave the Lower Mainland ground shaking for three to five minutes, she said, and could trigger a tsunami tidal wave that could endanger coastlines. However, given that the Vancouver area is guarded by Vancouver Island and the Gulf Islands, there would be almost no effect there.

There is a chance of more tsumami damage to the Lower Mainland if a major quake occurs in the Georgia Strait, which could trigger landslides and underwater landslides.

Bird says there is a chance that a large quake of 6.5 to 7.5 is possible on the southwest coast and that events that size or more common thaN the large "megathrust" events off the coast that can be centuries apart.

As for damage from the ground shaking, Bird says the Building Code of Canada has included seismic restraints on buildings since the mid 1980s, which applies to schools, hospitals, dams, bridges and other critical structures. Residences are generally not included as they typically do well in earthquake events, and more homes are being built to higher standards. For example, some homes are now bolted to their foundations.

While mountain areas like Whistler are naturally protected from tsunami activities, mountains can also concentrate the shock waves of an earthquake. For example, Bird says a mild earthquake in Hawaii a few years ago didn't cause much damage at sea level, but caused extensive damage to mountaintop observatories.

Bird herself reinforced the area around her chimney through her attic to prevent pieces of the chimney falling through the floor. She has also strapped her bookcases to the frame of her house.

The provincial government is currently carrying out seismic upgrades to older buildings, including schools. Myrtle Philip Community School is currently being brought up to the latest earthquake standards. It's the only Sea to Sky school receiving the upgrades after a review of all schools in the province.

Altogether, some 64 B.C. schools have received seismic upgrades, 29 have projects underway and 25 more are on the list.

Bird says the Provincial Emergency Program has done a good job informing people around the province about the risk of earthquakes and tsunamis, although in her opinion PEP's recommendation that people keep three-day emergency kits is optimistic.

"It can take a lot longer than that for things to get back to normal after a major earthquake, but honestly it's far better than doing nothing."

As for what to do when the ground starts shaking, Bird says the best advice is to take cover under heavy furniture and cover your head and torso rather than trying to get outside. Homes are generally good at absorbing earthquakes.

While coastal communities can learn in advance of tsunamis the only warning for an earthquake "is when the ground starts shaking," said Bird. "Unfortunately we can't tell when an earthquake is going to happen. We can say it's likely to happen within a given timeframe, but timeframes are huge. It's not something we are able to predict."