Cascadia Earthquake: 322 Years Later

Seattle’s Seismic History

On January 26, 1700, an earthquake shook Seattle.  The ground shook violently for up to 5 minutes, and the quake triggered a tsunami that caused waves as high as 33 feet in Washington and reached as far away as Japan. Landslides swallowed entire communities, forests were drowned, and our region was changed forever. 

On the 322nd anniversary of the Cascadia earthquake, we are reminded that Seattle is earthquake country. The Cascadia Subduction Zone is just one fault of the many that threaten Seattle, including the Seattle Fault, which runs through the city. 

Earthquake preparedness is an important part of living and working in Seattle. Creating a plan for your home, family, and workplace before an earthquake will help you after an earthquake. Learn more about creating a plan, gathering emergency supplies, and other ways to prepare on our website: seattle.gov/emergency-management/prepare

The City of Seattle also prepares for earthquakes. You can learn more about our earthquake response plans on our YouTube channel, where we’ve posted a series of videos detailing our plans to fight fires and rescue people trapped in damaged buildings, feed and shelter people who are displaced, restore transportation and utilities, and set response priorities after a major earthquake.

MyShake Earthquake Early Warning Now Available

We can’t prevent or predict earthquakes, but with earthquake early warning technology, we can get some warning before the shaking starts. 

Washington residents and visitors now have an additional way to receive seconds of warning before earthquake shaking arrives, giving them time to drop, cover and hold on to protect themselves. The MyShake App, which has already been delivering alerts in California and Oregon, will be available in Washington as of today, January 26.

Alerts based on information from the USGS ShakeAlert earthquake early warning system are already available to all mobile phones through the Wireless Emergency Alert (WEA) system and/or through a built-in-earthquake alerting system on the Android Operating System. MyShake provides a third option that may be a faster way for users to get an earthquake alert on their phones than the WEA system.

The ShakeAlert Earthquake Early Warning system uses ground motion sensors in Washington, Oregon, and California to detect earthquakes that have occurred and automatically notifies residents and visitors in advance of ground shaking. 

To learn more about the system and all the ways you can receive earthquake and other emergency alerts in Washington, visit mil.wa.gov/alerts.

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