A magnitude 4.2 earthquake shook Southern California's San Fernando Valley just before 4:30 a.m. Thursday, the United States Geological Survey said.

The light quake which felt like a jolt, a pause, and then a bit more rocking, was centered near Pacoima.

Pacoima is about 23 miles northwest of downtown Los Angeles.

The USGS initially reported a magnitude 4.5 tremor, but has since downgraded it.

Southern California’s San Fernando Valley encompasses the City of Burbank, the City of Calabasas, the City of Glendale, the City of Los Angeles, and the City of San Fernando.