On Thursday morning, the Shake Alert earthquake early warning system sent out a false alarm, erroneously notifying users of a magnitude 5.9 earthquake in Carson City, Nevada—a quake that never occurred. The alert was broadcast through both the My Shake app and the Wireless Emergency Alert system on phones throughout regions such as the San Francisco Bay Area, Sacramento, and eastern California just after 8 a.m. The erroneous earthquake report was later removed from both the My Shake app and the U.S. Geological Survey (USGS) earthquake website.
USGS officials confirmed that no earthquake was detected and have launched an investigation to determine the cause of the false alert. The Shake Alert system, which has a history of providing effective advance warnings for real earthquakes, has experienced issues before. Examples include a 2023 drill that was sent out at the wrong time due to a time zone error, and a 2021 incident where the system significantly overestimated the magnitude of an earthquake in Northern California due to technical limitations near the edge of its sensor network.
Officials are working to identify the source of Thursday’s error and to implement solutions to prevent similar incidents in the future.