Earthquakes Strike Southern California, Causing Concern

Ventura County Experiences Magnitude 4.0 Quake

A magnitude 4.0 earthquake struck Ventura County on Friday afternoon, approximately seven miles from the city of Ventura. The quake, which occurred at 3:08 pm, was widely felt throughout the county.

Santa Barbara County Records Magnitude 3.7 Tremor

In addition to the Ventura County quake, a magnitude 3.7 earthquake was reported in Santa Barbara County at 3:08 pm. This event was located 15 miles from Ojai and was also felt by many residents in the area.

Potential Mainshock of Earthquake Sequence

According to the United States Geological Survey (USGS), the Santa Barbara County earthquake is identified as the potential mainshock of an earthquake sequence. The USGS defines a mainshock as the largest earthquake in a series of seismic events that occur in the same location over a short period of time.

Increased Seismic Activity in the Region

These recent earthquakes come amidst a period of increased seismic activity in Southern California. In the past 24 hours, there have been zero earthquakes of magnitude 3.1 or greater in the region, and only one earthquake of magnitude 1.5 or greater in the past seven days. However, the USGS estimates an annualized average of 220 million earthquakes in Ventura County and 220 million earthquakes in Santa Barbara County.