The Cascadia Subduction Zone offshore produces rare but immense earthquakes, the most recent in January 1700, dated from the tsunami it sent to Japan and corroborated by Indigenous oral histories of the Pacific Northwest coast. Geologists find evidence of past events in drowned forests and buried sand layers along the shoreline, and another major quake is anticipated in the future.
Here's a sobering thing to know as you ride this coast. Just offshore runs a giant crack in the earth where one slab of the planet grinds beneath another, and every few hundred years it lets go all at once in an enormous earthquake. The last great one struck in the year sixteen ninety-nine, and we know it almost to the day, because the wave it flung across the Pacific was written down the next morning in Japan. The native peoples of this coast carried the memory too, in accounts of a night the ground shook and the sea came up. The signs are written all along this shore, for those who can read them.
Photo: Ron Clausen · CC BY-SA 4.0
