A 4.3-magnitude earthquake and a 3.5 aftershock rocked northern California on Tuesday, less than two weeks after large earthquakes struck south in the Mojave Desert. Shaking was felt in a wide area of the East Bay and people reported feeling it as far west as San Francisco, as far south as Menlo Park and as far east as Tracy, CBS San Francisco reported.
The earthquake hit at 1:11 p.m. PT and was centered about seven miles east of San Ramon, according to the U.S. Geological Survey. The epicenter was just west of the Los Vaqueros Reservoir. The initial jolt was followed 13 minutes later by a 3.5 magnitude aftershock.
The USGS said the quake hit on the Greenville Fault, a right lateral strike-slip fault much like all the other San Francisco Bay Area faults. The area has always been seismically active with a swarm of small quakes rattling the area in 2015.
"This area is no stranger to that type of magnitude," Ole Kaven with the USGS told CBS San Francisco. "There has already been one small aftershock. So we're keeping an eye in this."
"Unfortunately, there is no certainty whether this was the foreshock or if this was the biggest event," Kaven said. "The general rule of thumb for all California faults is that there is about a 1/20 chance that there will be a larger event after."
While here was no major damage, the quake did shake up local residents.
"It's been a while since I felt on earthquake," Melissa Miller, who lives in Pleasant Hill, told CBS San Francisco. "I noticed that the lamps on my table were shaking and my cat was going a little crazy. That roll-jerk kind of thing we feel when we have earthquakes."
Sarah who lives in Fremont was also jolted.
"I felt it really strong," Sarah who lives in Fremont told CBS San Francisco. "The building was rolling and it kept going. It didn't stop, it was a longer one."
Tuesday's quakes are less than two weeks after a 6.4-magnitude quake and a 7.1 quake struck in the Mojave Desert. There were thousands of foreshocks and aftershocks felt throughout the region.