Earthquake Alert System To Be Tested In San Diego County

SAN DIEGO COUNTY, CA – People in San Diego County will receive an earthquake alert Thursday. Don't panic! It's only a test.

The San Diego County Office of Emergency Services, along with the California Governor's Office of Emergency Services and the United States Geological Survey, will test a wireless emergency alert system Thursday on mobile phones throughout the county. The test is scheduled at 11 a.m. and will affect all mobile phones in the county area.

The test will evaluate the effectiveness of ShakeAlert, an earthquake early warning system. Much like Amber Alerts, ShakeAlerts will send mobile phones a message, preceded by a loud tone.

State and local officials have worked with the USGS to develop the ShakeAlert system since 2006, using underground seismic activity sensors to detect the first ripples of an earthquake.

The system's first phase went into effect last fall in California, Oregon and Washington. Eventually, USGS officials hope to expand the alert system across the country to alert people when a quake of magnitude 5.0 or above is about to strike.