OCOTILLO WELLS (KGTV) -- A 4.5 magnitude earthquake was reported Sunday at 3:07 p.m. southeast of Ocotillo Wells.
The quake caused brief shaking across San Diego County, according to the US Geological Survey.
Reports of shaking came from San Diego, Santee, El Cajon and Carlsbad.
Geologist Dr. Pat Abbott says the quake was in the San Jacinto Fault Zone, "This is one of the most active fault zones in all of California."
He said it was not most likely not related to the 4.9 quake in Anza April 3.
The quakes are related in a larger sense, he added, widening the Gulf of California.
"The Gulf of California is growing larger and if this is Baja California," he said referencing his left arm, "and this is San Diego," referencing his right arm, "we're pulling away."
He said there is a small possibility Sunday's quake was a foreshock, indicating a larger quake could be on the way.
If that happens, Dr. Abbott said seek shelter immediately, "making like a turtle, dive underneath a kitchen table, go underneath a desk, something like that."
He said being in your house is the safest place you could be.
Once the shaking stops, he said that's when you should check on your family, so you don't get hurt.