'False event:' No magnitude-4.0 quake near Catalina Island
The U.S. Geological Survey has confirmed that what it initially reported as a magnitude-4.0 earthquake near Catalina Island Friday morning never occurred.
The USGS first reported that an earthquake had struck at 9:48 a.m., with an epicenter about 18 miles southwest of the city of Avalon.
However, a seismologist with Caltech -- which operates the Southern California Seismic Network in conjunction with the USGS - confirmed to CBSLA later Friday that its automated system misinterpreted background data as an earthquake.
The seismologist told CBSLA that the USGS early warning system then triggered what is known as a "false event."
The data was reviewed by human seismologists, who determined that it was not a real earthquake, and it was removed from the record.
