Yesterday marks the anniversary of the largest earthquake ever recorded in North America— near Prince William Sound in southeast Alaska. The 9.2 Good Friday earthquake destroyed buildings and infrastructure in Alaska as it shook for almost four-and-a-half minutes and resulted in 131 deaths.
But it was the following morning that Washington felt effects of the quake. The tsunami that ensued from the subduction zone earthquake did damage along the west coast, washing over Washington as it spread south along Oregon and California.
Tsunami waves as high as 15 feet destroyed houses, cars, boats, and fishing gear. Waves of five to six feet high washed out a bridge on Highway 109 over the Copalis River.
Waves continued south, and took the lives of one person at the Klamath River in California, four people at Beverly Beach State Park in Oregon and eleven in Crescent City, Calif.
Check out DGER publication GM-49, Tsunami Hazard Map of The Southern Washington Coast: Modeled Tsunami Inundation from a Cascadia Subduction Zone Earthquake for more information and pictures from the 1964 Earthquake and Tsunami.
Warning system resulted
Fortunately, the quake didn’t just produce damage.
Recognizing the danger tsunamis present to coastal communities, emergency officials began posting signs to show tsunami evacuation routes along the Pacific Coast. Sirens were also added in coastal towns. Those warning systems were amplified after the devastating tsunami that swept through the Indian Ocean in 2004.
Boosting the warning
DNR’s Geology and Earth Resources Division, the State’s official Geologic Survey, is helping Washington communities identify how they are vulnerable to similar tsunami events and how they can craft innovative strategies for dealing with those threats.
DNR has produced tsunami inundation map to show how tsunamis would likely impact communities like Everett and the Pacific Coast. You can find interactive tsunami evacuation maps on DNR’s Geologic Information Portal.
DNR’s Geology Division also documents tsunami-related news in our bi-monthly newsletter, TsuInfo.
The agency is currently seeking additional funds from the Washington legislature to further map tsunami inundation zones so communities can be best prepared to handle another disaster.
The Washington Emergency Management Division says the best way to survive any type of disaster is to have a plan and keep informed. Find out if you are in a tsunami inundation zone. Mobile and desktop apps are available from the Northwest Association of Networked Ocean Observing Systems (NANOOS) called TsunamiEvac-NW.
Download a tsunami evacuation brochure for your community. DNR works with local governments to produce these brochures.