How often do you think about a sizable earthquake hitting San Diego? The guess is not usually.

On Monday, April 14 at 10:08 a.m., many San Diegans got a short but notable wakeup call. A 5.2 magnitude earthquake in the Julian area was felt throughout much of San Diego County.

The quake’s epicenter, approximately two miles south of the mountain community, rattled nerves for many miles away. Monday’s quake struck as many individuals were at work, in school, in their homes, etc.

There were no reports of any recognizable damage or injuries throughout San Diego County.

While notable earthquakes around the area are uncommon, one San Diego State University professor said it is important for residents not to sleep on the possibility of them happening on occasion.

Rafael Almeida, SDSU assistant professor of geological sciences, noted Monday’s quake was not unexpected. Predicting exactly when one will hit again is an entirely different matter.

“It is important to note that the San Andreas Fault system, which accommodates the northward motion of the Pacific plate with respect to North America (at a rate of about 2 inches or 50 milimeters per year), is composed of many faults that span from the offshore Borderlands in to the eastern side of the Salton Trough,” Almeida stated. “Some of these faults slip faster than others, and will have different probabilities of causing a large earthquake. However, predicting when an earthquake will occur is pretty much impossible.”

According to Almeida, the main faults that cross San Diego County are the Elsinore Fault, the one that ruptured Monday, and the Rose Canyon Fault. Both of these faults are among the “slower” faults in the San Andreas system (accommodating between 2-10% of its total motion) and therefore probably have longer intervals between earthquakes. “However, it is important to be prepared by having your earthquake kit ready and securing furniture and appliances that could topple over during shaking,” Almeida added.

When asked how soon San Diegans may forget this event and might even overlook future quakes, Almeida noted, “As earthquakes go, a magnitude 5.2 is fairly small and will probably not be remembered the same as the 2010 El Mayor earthquake (M7.2, which emits about 1,000 times more energy), for example. These earthquakes are important, though, because they are a gentle reminder that even these small events have the ability to jolt us, and hopefully spur us to take seismic hazards seriously and prepare accordingly.”

Image credit: earthquake.usgs.gov/