The USGS says ShakeAlert detected a strong one. "Intensity level of shaking as high as intensity 8.0 were estimated by the ShakeAlert system," said Robert de Groot with USGS.

USGS says its ShakeAlert Earthquake Early Warning System performed "as expected during this earthquake" with warnings sent to at least 95,000.

The United States Geological Survey (USGS) announced a new update to its earthquake alert app that aims to give advance notice seconds before some of the strongest earthquakes hit. The ShakeAlert ...

Preliminary readings said the Thursday earthquake had a magnitude of 5.7, but the USGS updated its reading to 5.5. The earthquake was followed by several aftershocks that ranged from 2.5 to 3.8 in ...

“While rare, earthquakes greater than magnitude 7 can have the greatest impact on human lives and infrastructure,” Robert de Groot, with the USGS ShakeAlert Operations Team, said in a statement.

The 4.2 magnitude earthquake was "too small to trigger the delivery of #ShakeAlert-powered alerts to cell phones," USGS ShakeAlert wrote on Twitter.

Shasta County and Redding Residents woke up shortly before 4 a.m. Friday morning to a 3.7 Magnitude earthquake, according to ...

The U.S. Geological Survey (USGS) and EarthScope have started using GPS sensors in the ShakeAlert system, they announced on Wednesday. Up until this change, ...

The magnitude 4.5 earthquake triggered ShakeAlert, ... People within the boundary of MMI 3, which is the outer blue line, may have received a ShakeAlert notification, according to USGS.

USGS says its ShakeAlert Earthquake Early Warning System performed “as expected during this earthquake” with warnings sent to at least 95,000.