M7.7 Earthquake in the Queen Charolette Islands, BC

Tonight, BC had a big earthquake today (M7.7), with substantial aftershocks (M5.8, M4.8, M5.1, M4.7, M5.1…).

Tsunami warnings were issued for the north coast and western Vancouver Island. Movement was primarily lateral, not vertical, so hopefully the tsunami will be small. You can track updates via the Pacific Tsunami Warning Centre. As of posting time, it’s at the maximum alert level, Tsunami Warning, so get to high ground if you’re on an exposed coastline. The tsunami warning does NOT apply to Vancouver city, or any of our nice sheltered locations with the bulk of Vancouver Island between us & them. Any waves will be so attenuated that by the time they get in here, at worst we’ll get some weird currents. I’d recommend against taking a midnight swim tonight, but residents of Richmond do not need to head to high ground.

This is one of the biggest earthquakes in recorded Canadian history, but in a region with the capacity for megaquakes (M9+), this was not the long-awaited Big One. Earthquake magnitude is a logarithmic scale, so this earthquake released essentially none of the energy built up by locked plates.

The Queen Charolette Islands have a population density of approximately 25 people per square kilometer, while the north coast has a population density of 0.5 to 5 people per square kilometer, very few people are within the direct impact area. If you are one of the few, and felt the earthquake or any of the aftershocks, please fill out a Did You Feel It? report.

Google is maintaining a Crisis Map of ongoing earthquakes, and any related tsunami evacuation areas.

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