More than 1.5 million people across Washington have registered to participate in the worldwide Great ShakeOut earthquake and tsunami drill. The annual exercise is scheduled for Thursday, Oct. 15.
Testing the Emergency Alert System Across Washington
The statewide drill begins at 10:15 a.m. when the Emergency Alert System activates. The National Weather Service’s NOAA Weather Radio network will broadcast the signal statewide alongside local radio and television broadcasters, including KIRO FM 97.3, Seattle Sports 710 AM, and 770 Seattle Red. Outdoor tsunami sirens will also test their actual wailing sound across coastal regions at the same time, prompting emergency management authorities to urge residents not to call 911 in response.
Participants worldwide practice dropping, covering, and holding underneath a sturdy desk or table to prepare for sudden seismic events. Because earthquakes occur without warning, emergency planners emphasize that the drill can happen anywhere daily life takes place—at work, in schools, or on the road. For individuals asleep when a tremor hits, safety guidelines recommend staying in bed, protecting the head with a pillow, and keeping hard-soled shoes, flashlights, and gloves nearby to avoid injuries from walking barefoot in the dark.
Cascadia Subduction Zone Risk and Tsunami Evacuation
Recent smaller earthquakes near Vancouver Island and across Western Washington serve as reminders that the state is the second most threatened in the nation for seismic activity behind California. Multiple active faults run through the region, including the Tacoma fault, the Seattle fault, and the South Whidbey Island fault, each capable of producing 7.0 magnitude quakes or greater.
The region also faces the Cascadia Subduction Zone, located about 100 miles off the coast and stretching from northern Vancouver Island to northern California. Geological records show this zone last ruptured on Jan. 26, 1700, producing an estimated 9.0 magnitude tremor that generated a Pacific-wide tsunami. Geologists note that this subduction zone releases accumulated pressure roughly every 300 to 500 years, similar to the fault system off the coast of Japan that produced a major earthquake and tsunami in March 2011.
In low-lying coastal tsunami inundation zones, significant ground shaking serves as the primary warning before waves arrive. Alongside the indoor drop-and-cover exercise, coastal schools and residents plan to practice walking their tsunami evacuation routes to higher ground or vertical evacuation structures.
Backup Communication and Emergency Preparation Resources
Because phone and power systems are likely to fail or become overwhelmed following a major earthquake, emergency management encourages households to establish backup communication plans in advance. Residents can also download the ShakeAlert app for early warnings on distant quakes.
For additional guidance on household preparation, the Washington State Emergency Management provides a 12 steps to Prepare in a Year Guide. More information on local alerts and early warning systems is available through mil.wa.gov/alerts.
