Several small earthquakes have jiggled the ocean floor off Southern California.
A magnitude-3.1 quake at 8:52 a.m. Tuesday was the closest to the mainland, occurring under Santa Monica Bay four miles west of Hermosa Beach.
The U.S. Geological Survey's community reporting system indicates it was felt lightly along much of the Los Angeles County coast.
Three other undersea quakes were recorded earlier at the western end of the Channel Islands.
The USGS says the largest was a magnitude-3.6 tremor off San Miguel Island at 2:09 a.m. The area about 60 miles southwest of Santa Barbara also had quakes of magnitude 3.4 and 2.5 within the following hour.