By Margaret Munro
VANCOUVER – Anacla, a First Nations village on the west coast of Vancouver Island, is moving up, heading for higher, safer ground.
A new “big house” has been built 50 metres up from the pounding surf of Pachena Bay. And there are plans to replace the 49 houses on the beach, which could be swallowed by the sea with just minutes’ notice.
It has happened before, says Tom Happynook, a hereditary chief with the Huu-ay-Aht First Nations, recalling how the village in the bay vanished in 1700, when a quake kicked up giant waves off Canada’s West Coast.
“The village was completely wiped out,” says Happynook.
Scientists say the strain is building again beneath the sea floor as enormous tectonic plates push against each other about 100 kilometres offshore.
A monster earthquake rivalling the one that devastated Japan last March is all but a certainly on North America’s Pacific coast, they say.
No one can say when it will occur, but when it does a huge and powerful wall of water could hit the outer coast areas within 30 to 45 minutes.
“They’ll be no time to collect the family photos,” says geologist John Clague, who says Canada – and Canadians – could learn much from Japan’s triple disaster that occurred a year ago Sunday.
More than 16,000 people in Japan died in the aftermath of the magnitude 9 earthquake, most of them from the tsunami that rolled ashore sweeping away cars, trucks and boats. Waves surged into homes, and reduced communities to rubble.
The tsunami also crippled the Fukushima Daiichi nuclear station, leading to meltdowns, explosions and leaks that sent radioactive isotopes drifting around the globe.
One of the biggest lessons from the Japanese tragedy is that “what can wrong, will go wrong,” says Clague, director of the centre for natural hazard research at Simon Fraser University in Burnaby, B.C.
“You have to anticipate the worst-case scenario,” he says, “and have plans in place to deal with it.”
The Japanese are famous for their earthquake preparedness, but things went terribly wrong as last year’s quake unfolded.
Authorities and scientists had overlooked evidence that Japan’s northeast coastline was prone to large quakes and tsunamis, and missed the chance to strengthen their defences and improve reactor safety.
And while thousands of people did outrun the surging water, many wasted time before fleeing to higher ground – one survey found that 40 per cent of people who had received a tsunami warning waited before evacuating.
But plenty of things did go right, says Garry Rogers, a research scientist and quake expert at Natural Resources Canada.
Loss of life due to collapsing buildings was the least of Japan’s problems, showing the value of tightening building codes to ensure structures can withstand intense shaking. “Building codes work,” says Rogers.
So did Japan’s early warning system that automatically stopped high-speed trains in their tracks, and issued a tsunami alert within three minutes of quake.
“It didn’t work perfectly, but it worked,” says Rogers, who would like to see a similar early warning system in Canada.
“If you have to run for a hill, extra minutes can make the difference,” says Rogers. He is Canada’s representative to the Pacific Tsunami Warning System, an international organization working to reduce casualties from the giant waves.
Rogers also leads the seismic program at Neptune Canada’s sea floor observatory off Vancouver Island, which is giving an unprecedented look at the geological forces building offshore.
Canadian researchers and their colleagues from Japan and the U.S. – who hope to apply what they learn in Canadian waters to fault zones elsewhere – are anchoring seismographs, pressure gauges and tilt-metres on top of that locked fault zone. They also hope to have a super-sensitive “tsunami-meter” operating later this year 2,000 metres below the water surface.
The scientists expect the region to eventually unleash an earthquake of magnitude 9 or more. It could tear down the fault zone from Vancouver Island to Northern California.
The ground is expected to shake so violently that people in coastal communities on Vancouver Island could have trouble standing for three to five minutes.
And the sea floor will heave creating a tsunami that will roll towards shore. Models suggest waves three metres high will hit the outer coast and inundate low-lying areas. Scientists say the waves could double and triple in size as they race up inlets. Fish farms, logging camps and low-lying communities tucked in bays and inlets could be devastated, Clague says.
“One doesn’t want to be alarmist,” says Clague, but he suggests that tourists at seaside hotels in popular West Coast destinations such as Tofino and Ucluelet should be warned of the danger and how they’ll have half an hour to find higher ground.
Victoria will have longer – likely more than an hour – before the icy waters of the Pacific inundate its harbour and low-lying residential areas.
Another hour and water could start breaching the dikes south of Vancouver, possibly flooding Vancouver International Airport. The waves could also knock ferry and port facilities out of commission, says Clague. “The impact could be huge.”
The threat is compounded because many Canadians are afflicted by what Clague calls “rare event syndrome” – a phenomenon that he says occurs when the potential for catastrophe is real, but the frequency is so low that many people don’t take the threat seriously.
Unlike Japan, where quakes are common, damaging quakes are rare in Canada. And megaquakes are exceedingly rare.
The last one hit the Pacific coast more than 300 years ago. First Nations oral history tells of canoes being tossed up into trees and entire villages – like the one in Pachena Bay – vanishing in the night.
That quake sent a tsunami racing across the Pacific, and the arrival time was noted when the waves washed ashore in Japan. “They had good timekeeping,” says Rogers, explaining how the Japanese record enabled researchers to determine that the quake struck off Vancouver Island at about 9 p.m. in the evening Jan. 26, 1700.
Such quakes occur with centuries-long frequency in the Pacific Northwest. Researchers have uncovered buried marshes and submarine landslides that they have linked with 22 “megaquakes” going back 10,000 years along the Cascadia subduction zone, which runs along the coasts of Oregon, Washington and British Columbia.
They strike on average about every 500 years, says Rogers: “We have a 10,000-year record of big tsunamis, and we know that the earthquakes can be magnitude 9, perhaps even slightly larger.”
The quakes occur offshore where the ocean floor is trying to slide under, or subduct beneath, western North America. The Juan de Fuca tectonic plate moves eastward at two centimetres a year and is trying, unsuccessfully, to slip beneath the North American plate which is moving westward at two centimetres a year.
The plates are locked and the rocks are being squeezed and uplifted by the relentless movement of the plates, says Rogers.
The scientists say public education is needed to drive home the danger and the message that people will need to protect themselves when the big one finally lets loose off Canada’s West Coast.
But they also say existing technology and know-how could help save lives and limit damage.
The technology exists – some has been devised in Canada – to create much more detailed maps of the “inundation” the tsunami could generate.
Oceanographer Richard Thomson, at Fisheries and Oceans Canada, says the Americans have done a much better job of modelling and projecting what could happen along the U.S. coast.
But the detailed maps “stop at the Canadian border,” says Thomson.
The B.C. government, working with the federal scientists, has issued general information on how big the waves could be and when they might arrive. But Thomson says it is “very basic.”
“Every part of the coast has its own response characteristics,” says Thomson.
“You can’t just draw a line on a map based on a guess of what the tsunami will be,” he says, noting that some inlets and channels could see three to four metre waves amplified up to 16 metre walls of water.
“We really should be taking a more proactive approach to doing tsunami inundation models for coastal communities using state-of-the-art numerical models,” says Thomson.
The expertise exists within the federal government, but he says funding for such work is scarce. He estimates it would take a few hundred thousand dollars and a couple of years to develop detailed maps.
Rogers says an early warning system could also give a more accurate and timely read on when giant waves will hit and how much seismic energy has been unleashed.
Japan is the only country with such an early warning system and he says it saved thousands of lives last March.
It added “precious minutes” to tsunami warnings and gave emergency responders a better read on the unfolding disaster, says Rogers.
He says Canada now gets tsunami alerts from the Pacific Tsunami Warning System, an international co-operative, which gathers real-time seismic data from countries including Canada and issues an automatic warning when a tsunami is expected. The alerts typically go out 10 to 20 minutes after the quake – which Rogers and his colleagues say is fine if the tsunami is not expected to wash ashore for hours.
Early warning systems, such as the one in Japan and a related system that has been tested but is not yet operational on Canada’ s West Coast, can get alerts out within two to three minutes of the quake, says Rogers.
“The technology is there and the knowledge is there and it is not highly expensive,” Rogers says.
“Once you have the instruments in place you can do early tsunami warning, you can have situational awareness” which can be invaluable for emergency responders who need to know what they are dealing with, he says. And when there is not a disaster unfolding, Rogers says the system could be use by scientists to assess quake hazards and by engineers working to improve building codes.
But the scientists stress that public education is key. People in areas prone to tsunamis need to understand the risks and be prepared to run for higher ground when the ground shakes and plan now on how best to escape.
Huu-ay-Aht First Nations has opted for pre-emptive action, and with good reason as the village is “extremely vulnerable,” says Rogers.
Elders have long recalled how the village in Pachena Bay was washed away in 1700, and the community’s government has committed to moving people from the 49 beachfront homes up the hill to safer ground. Happynook expects it will take about 10 years to get new homes built and move everyone out of the tsunami danger zone.
If the quake and tsunami hit before then, the plan is to evacuate people to the community’s big house – about a 20-minute walk up from the beach – where there are food and water supplies.
But the community’s more immediate worry is with the debris from the Japanese tsunami now being swept across the Pacific.
“It is a big concern for us,” says Happynook, whose council is keen to meet with federal and provincial government about the material expected to start washing ashore on Vancouver Island in the coming year.
“We need to start a big discussion and develop a plan on how do deal with this,” says Happynook, noting that his community has only limited landfill space and some material may need to be returned to Japan. “It will be a huge cleanup, and what do we do with it.”
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