OTTAWA - Canada could expect a major earthquake at any time and a top geophysicist says it should prepare itself if it is to avoid the kind of disasters that befell Japan, Italy and China in recent years.
John Cassidy, head of earthquake seismology at the Geological Survey of Canada, says large earthquakes have hit parts of Canada numerous times — and will again.
"Certainly we could expect an earthquake at any time and should be prepared for a large earthquake at any time in Canada," Cassidy said in an interview prior to delivering a lecture at Carleton University.
"We've seen many over the years, going back in time."
He says the most vulnerable region is the West Coast, which has been hit with giant, magnitude-9.0 quakes 13 times in the last 6,000 years, the last of them 311 years ago.
B.C. is in the window in which a massive earthquake is more likely to occur, he says, but he acknowledges that window spans 200 to 850 years.
Predicting earthquakes with any degree of consistency, Cassidy says, remains next to impossible.
"Unfortunately, we cannot predict earthquakes, either here or anywhere," he said. "There's no consistent, successful way to predict exactly when earthquakes will occur and how large."
The only thing people can do is be prepared, he says.
Canada is identifying vulnerable areas, estimating potential magnitude, frequency and type of quakes. Using that information, planners can draft appropriate building codes and construct quake-resistant infrastructure to minimize the damage.
"Our real protection from earthquakes are earthquake-hazard maps that are improving over time as we learn more about earthquakes, where they occur and how large they can be."
Training is also important, he stresses. Fatalities from the magnitude-8.8 quake in Chile were kept to a minimum in February 2010 because people knew what to do, he said.
It may seem like there have been more major quakes worldwide in recent years, but Cassidy says that's more perception than reality.
It's true that there have been three 8.8-magnitude quakes in seven years — in Sumatra, Chile and Japan — the biggest tremors since the 1960s.
But he says the perception is also due to the fact that some other quakes, like those which struck Christchurch, New Zealand last year and L'Aquila, Italy in 2009, hit close to major centres, maximizing damage.
Besides the West Coast, other seismic hotspots in Canada include the Ottawa and St. Lawrence valleys, the North Atlantic off Cape Breton and the Arctic off Baffin Island.
The quietest seismic region incorporates Saskatchewan, Manitoba and Northern Ontario.