Earthquake, Tsunami Overdue for Vancouver Island

The odds of another earthquake and tsunami hitting within 50 years is one in ten.

It’s only a matter of time before another tsunami devastates the outer coast of Vancouver Island, says University of Victoria ocean engineer Kate Moran.

Scientists predict the earthquake’s epicenter will be Pachena Bay.

On January 26, 1700, a 9.2 magnitude earthquake struck the Pacific coast. Immediately after, a tsunami swept everything along Vancouver Island’s outer coast into the ocean. Nine hours later, a tsunami the height of a four-story building struck the Japanese coast. Scientists only discovered the connection between the two disasters in the 1990s.

Vancouver Island sits above two locked geological plates under the sea floor.

The plates are “locked, yet they are still moving toward each other,” says Natural Resources Canada seismologist Alison Bird. “The stress builds up over hundreds of years and when it releases, it releases in a megathrust earthquake.”

It takes 300-500 years for these major fault lines to build up enough pressure for an earthquake. The odds of another earthquake and tsunami hitting Vancouver Island within 50 years is one in ten, says Bird.

Moran draws comparisons between the 1700 earthquake and the 2004 Boxing Day tsunami in the Indian Ocean. A major rupture of the earth triggered both events, which she describes as “ripping open the earth’s zipper.”

If a similar earthquake occurred now, people in Pachena Bay and elsewhere on the western coast of Vancouver Island would have 15-20 minutes to escape. Victoria would see tsunami waves between two and four metres within 75 minutes. Vancouver would avoid the tsunami but the earthquake would be strong enough to damage buildings.

 

Take a look at our November 2014 feature, “Is the Industry Ready for an Earthquake in Quebec?”

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Transcontinental Media G.P.