EarthquakesEarthquake Early Warnings Launched in Washington
When the Big One hits, the first thing Washington residents notice may not be the ground shaking, but their phone issuing a warning. This week, the ShakeAlert early warning system was activated in Washington state, and it will send earthquake early warnings throughout the state.
When the Big One hits, the first thing Washington residents notice may not be the ground shaking, but their phone issuing a warning. The U.S. Geological Survey, the University of Washington-based Pacific Northwest Seismic Network and the Washington Emergency Management Division on Tuesday, May 4, will activate the system that sends earthquake early warnings throughout Washington state. This completes the tri-state rollout of ShakeAlert, an automated system that gives people living in Washington, Oregon and California advance warning of incoming earthquakes.
“For the first time, advance warning of imminent earthquake shaking will be a reality in our region. Even just seconds, up to a minute of warning is enough to prepare yourself and take cover — actions that may spare you from injury or even save your life,” said Harold Tobin, a UW professor of Earth and space sciences and director of the PNSN, which operates the seismic monitoring in Washington and Oregon.
Once the system goes live on May 4, the first signs of an earthquake above a magnitude 4.5 or 5, about when the shaking becomes noticeable indoors, will trigger an alert and a reminder to drop, cover and hold on. Warning times range from a few seconds to tens of seconds depending on your distance to the epicenter. The launch will be silent — there will be no test on May 4.
The PNSN operates a growing network of about 230 seismic stations in Washington and some 155 stations in Oregon that provide data for ShakeAlert. When four or more of these instruments detect unusual shaking, that motion is analyzed by computers, some of them on the UW campus, that quickly calculate the size and location of the event.
People connected to the Wireless Emergency Alert system (the same system that produces AMBER alerts), will now get earthquake alerts for events of magnitude 5 or greater, using a similar interface. Alerts for events of magnitude 4.5 or above will be integrated into Android devices, where screens will also show the earthquake’s approximate magnitude and location. When people get an alert, they should use the brief warning to seek immediate protection, following this safety advice. No downloads are required – find out how to get alerts.
