An undersea earthquake off La Jolla rattled parts of the county Saturday morning, but there were no reports of damages or injuries.

The quake, which measured a magnitude 4.0, struck at 7:34 a.m. about 19 miles southwest of La Jolla and 22 miles west of Coronado, according to the U.S. Geological Survey.

A dispatcher with Coronado police said she felt a little shake but got no phone calls regarding the quake.