Cascadia Subduction Zone
1700 01 26
This earthquake, the largest known to have occurred in the "lower 48" United States, rocked Cascadia, a region 600 miles long that includes northern California, Oregon, Washington, and southern British Columbia. The earthquake set off a tsunami that not only struck Cascadia's Pacific coast, but also crossed the Pacific Ocean to Japan, where it damaged coastal villages. Written records of the damage in Japan pinpoint the earthquake to the evening of January 26, 1700.