You can see the way the last major earthquake in 1700 shoved the ocean floor up at an angle. It’s part uplifting as well as subsidence of the sea bed right off shore. Mother Nature sure hates to be bored. In fact another subduction zone earthquake is due anytime. They tend to occur every 250 to 350 years. The last Cascadia Subduction Zone earthquake was in January 1700. Do the math. Those living on the coast should always have stocks of food, drinking water, lanterns and a portable, battery operated radio to keep in touch with the outside world. A CB radio with a hand-crank wouldn’t be a bad idea either.