5.2-magnitude SoCal earthquake triggers ShakeAlert warnings to countless cell phones

A 5.2-magnitude earthquake rumbled through Southern California Monday morning, causing minor damage in areas outside San Diego and triggering ShakeAlert warnings to countless cell phones.

The earthquake struck just after 10 a.m. near the town of Julian, a mountain town of roughly 1,500 people in San Diego County. There have been reports of items tossed from shelves and boulders coming down onto rural roads.

Experts say Monday's earthquake came less than a day after a smaller quake struck the same area, but they don't expect a larger one to hit.

"There was a foreshock to this earthquake," said seismologist Lucy Jones. "There was a 3.5 yesterday afternoon. The chance that this 5.2 would itself be a foreshock to something bigger is still the same. It's about a 5% chance."

When the ShakeAlert went out, it reported the quake as being 6.2-magnitude, but experts say inaccuracies like that are inherent to the current warning system because its goal is to notify people as soon as possible.

"The alerting system really tries to get the information out as quickly as possible, and that is to alert people if there is danger of shaking," said Allen Husker of the Southern California Seismic Network.