As Southern California braced for a highly unusual summer storm Sunday afternoon, residents were struck by a much more familiar phenomenon: a magnitude 5.1 earthquake, according to the US Geological Survey.
The epicenter of the quake was in Ojai, between Santa Barbara and Ventura, and it occurred along the Sisar fault, USGS data showed.
There were no immediate reports of damage, the Ventura County Sheriff said in a social media post. County aviation units later reported no damage after flying over the Lake Casitas and Matilija dams and the city of Ojai.
Shaking was felt throughout Los Angeles and surrounding communities, according to a USGS tool that allows residents to self-report their experience.
There were no initial reports of injuries or structural damage in Los Angeles, according to the city's fire department. First responders from all 106 stations are in "earthquake mode," surveying their areas and looking for damage to power lines, transportation infrastructure, apartment buildings and large gathering sites.
About 50 miles away in Valencia, the quake felt like a slow roll, lasting about 20 seconds. Residents reported a slow-rolling effect in the Hollywood area, as well.
At least two aftershocks — measuring 3.1 and 3.6 — followed the initial quake.
Earthquake expert Dr. Lucy Jones said it appears to have been preceded by a small foreshock sequence that began Saturday morning.
USGS seismic reports are preliminary and are sometimes adjusted.