Where is Metro Vancouver vulnerable during a major earthquake?

When the next major earthquake hits the Metro Vancouver area, its effect will vary wildly throughout the region, with some neighbourhoods being hit hard and some left relatively unscathed.

Much of this phenomenon has to do with how seismic waves move, and what lies beneath our feet.

“Vancouver has a highly variable geology,” said Dr. John Clague of the department of earth sciences at Simon Fraser University. “The best areas of Vancouver if you’re really worried about earthquake – which we all should be – are areas that are founded on bedrock.”

Bedrock is considered the gold standard for solid ground, and that’s where the motion from tremors would be less severe.

The downtown core, Stanley Park, Queen Elizabeth Park, and parts of the North Shore are examples of places on bedrock.

The areas where people would feel the most shaking, or amplification, are neighbourhoods built on relic glacial sediments, Clague says.

They are found all over Metro Vancouver and the Fraser Valley, and tremors would feel two to three times more intense in those locations that they would on bedrock.

People living in low-lying areas such as Richmond would also experience greater swaying.

“And that can be very destructive of course, because you know the higher, the more intense, the more powerful the ground motion, the more damage you’re going to experience,” said Clague.

City engineers and scientists are busy mapping out a clearer picture of which areas are most vulnerable in a quake – work that will be invaluable when updating building codes, deciding what to construct, and what to retrofit for increased seismic safety.