3.5 magnitude foreshock reported before San Diego earthquake

JULIAN, Calif. (KABC) -- Many people wondered if Monday morning's 5.2 magnitude earthquake near San Diego could be a precursor for another one.

According to seismologist Dr. Lucy Jones, every earthquake could be a foreshock to something bigger. She said her team hasn't found any characteristic that Monday's earthquake will or won't be a foreshock.

She said essentially, a foreshock is a main shock that happened to have a really big aftershock.

"There was a foreshock to this earthquake," she said. "There was a 3.5 [Sunday] afternoon. The chance that this 5.2 would itself be a foreshock to something bigger is still the same. It's about 5% chance. So it means, you know, 19 out of 20 times, what you're seeing is the biggest one, one out of 20 times it's followed by something bigger."

READ MORE | 5.2 magnitude earthquake near San Diego rattles parts of LA and Orange counties