According to preliminary measurements, the magnitude-4.2 earthquake hit at 12:41 a.m. Thursday, seismologist Randy Baldwin of the U.S. Geological Survey said. The USGS said the quake was centered about 40 miles south of Catalina island and about 60 miles off the coast of San Diego.
Police in San Diego and Oceanside say they have not received calls about the quake.
The USGS Earthquake Information Center has received about 50 reports of people feeling the temblor, but none of them reported any damages, Baldwin said.
"These aren't really damaging magnitudes," Baldwin said.
Avalon has a population of about 3,500 that can swell to more than 10,000 on weekends and in summer, according to the Catalina Island Chamber of Commerce and Visitors Bureau.
The quake struck closest to San Clemente Island, the uninhabited southernmost of the Channel Islands, which is used for training by the U.S. Navy.