The epicenter was located about 7 miles northwest of city of Malibu. 4.6 magnitude earthquake northwest of Malibu. A magnitude-4.6 earthquake northwest of Malibu caused widespread shaking that was felt early Friday afternoon from the coast to inland areas of Southern California. The quake was reported just before 2 p.m. about 7 miles northwest of Malibu in the Santa Monica Mountains. More than a dozen aftershocks, the largest of magnitudes 3.0 and 2.7, were reported within an hour in the same area. It was felt from the Malibu coast north to Bakersfield, south to San Diego and east to downtown Los Angeles. Some people said they felt the quake as a jolt, while others described more of a swaying motion.