Earthquake. The entire North American west coast sits on the boundary of the Pacific tectonic plate, so it's a subduction zone. Same reason California and Japa

Earthquake. The entire North American west coast sits on the boundary of the Pacific tectonic plate, so it's a subduction zone. Same reason California and Japan are known for large earthquakes. See also: https://en.wikipedia.org/wiki/Ring_of_Fire https://en.wikipedia.org/wiki/Ring_of_Fire