Entire U.S. West Coast Now Covered By Earthquake Early Warning System

In this Jan. 3, 2019, file photo, a mobile phone customer looks at an earthquake warning application on an iPhone in Los Angeles. An earthquake early warning system operated by the U.S. Geological Survey has been activated in Oregon, California, and now Washington.

Cell phone users from the U.S. border with Canada south to the border with Mexico should receive a mobile alert from the early warning system when an earthquake is detected.

(Image credit: Richard Vogel/AP)