ShakeAlert—Earthquake Early Warning System for the US Western States

Early Earthquake Warning diagram (click image for full details)

Detailed Description


 Earthquake early warning systems like ShakeAlert work because the warning message can be transmitted almost instantaneously, while shaking waves from the earthquake travel through the Earth at speeds of a few miles per second. When an earthquake occurs, seismic waves—including compressional (P) waves, transverse (S) waves, and surface waves—radiate outward from the epicenter. The faster but weaker P waves trip nearby sensors, causing alert signals to be sent out, giving people and automated electronic systems some time (seconds to minutes) to take protective actions before the arrival of the slower but stronger S waves and surface waves. Computers and mobile phones receiving the alert message can calculate the expected arrival time and intensity of shaking at your location. USGS image created by Erin Burkett (USGS) and Jeff Goertzen (Orange County Register).


Image Dimensions: 3000 x 1300

Location Taken: US


ShakeAlert—An earthquake early warning system for the United States west coast
Abstract First posted August 29, 2014 Revised February 8, 2017 For additional information, contact: Earthquake Science Center—Menlo Park, Calif. Office U.S. Geological Survey 345 Middlefield Road, MS 977 Menlo Park, CA 94025 Earthquake early warning systems use earthquake science and the technology of monitoring systems to alert devices and people when shaking waves generated by an earthquake are expected to arrive at their location. The seconds to minutes of advance warning can allow people and systems to take actions to protect life and property from destructive shaking. The U.S. Geological Survey (USGS), in collaboration with several partners, has been working to develop an early warning system for the United States. ShakeAlert, a system currently under development, is designed to cover the West Coast States of California, Oregon, and Washington.