California’s 2025 Tsunami Preparedness Week is in the books. What did it accomplish? Three things I hope: a test of North Coast counties’ emergency notification system, an opportunity for California emergency managers to practice responding to a tsunami event, and a time to bombard you with tips and information about tsunamis and what to do when one approaches. For some of you, it did something even more important — on Wednesday, you walked your evacuation route, developing the muscle memory to do the right thing when a major tsunami arrives.There is a reason why California chooses the last week in March to focus on tsunamis. This marks our worst historic tsunami disaster. On March 27, 1964, at 5:36 p.m. local time in Alaska, a small crack formed near the north shore of Alaska’s Prince William Sound. As that crack grew, the ground shifted around it changing the coastline of southern Alaska forever. When the rupture finally stopped more than a minute later, a 500-mile-long fault had ruptured causing the land around it to uplift and subside.Our 2025 tsunami week focus was to flip the tables, so to speak — to pretend what happened in Alaska in 1964 was here and Alaska got our tsunami four hours later. Geologic evidence suggests more than a dozen of these earthquakes have occurred over the last several thousand years ranging in magnitude from the upper 8s to 9. The most recent was on January 26, 1700. The source is the Cascadia subduction zone extending from Cape Mendocino to Vancouver Island, Canada.It’s much more difficult to prepare for a Cascadia earthquake and tsunami than for a repeat of what happened in 1964 or in 2011 when we had more than 9 hours before the Japan tsunami reached us. The 1964 Alaska experience from the Alaska perspective provides useful guidance on what to expect.• There will be no official warning or guidance on what to do or what to expect. The first 30 seconds of shaking will knock out our power, trigger landslides, and make roads impassable. No internet, no phones, no one knocking on your door. You will get an alert that something is up — more than a minute of ground shaking.Next time the ground shakes for a long time, I hope it makes you think:1. DROP, COVER, HOLD ON or stay in one spot while the shaking lasts2. Am I in a tsunami zone? If YES, evacuate as soon as I can safely move. If NO, stay put!You can sign up for Humboldt County's emergency notification system to get texts, emails, and/or phone calls.For more info aboute tsunamis safety, including tsunami hazard maps, visit the Redwood Coast Tsunami Working Group.Read Entire Article
