A cluster of small earthquakes rattled the Salton Sea area overnight in the desert southeast of Los Angeles.
About 35 earthquakes, ranging in magnitude up to 3.5, were reported overnight and into late Monday morning in the historically active seismic area. Clusters of quakes like this are not unusual in the region, suggesting the seismic activity is not cause for alarm, according to the USGS.
Last month, about 200 minor quakes were reported in the area, including nearly 100 with a magnitude over 2. The largest quakes in that September swarm were magnitudes 4.3 and 4.1 on Sept. 26, when the activity began.
The swarm of quakes near the southern tip of the San Andreas Fault, California's longest fault, subsided earlier this month. The earthquakes, near a set of cross-faults beneath the shallow Salton Sea, led scientists to determine there was a slightly elevated risk for a large quake along the San Andreas Fault.
The probability of a major quake on the San Andreas during any one week has been put at 0.02 percent. The probability for the week following the September cluster was increased to 0.04 percent and 1 percent.
No such increased probability was associated with Monday's swarm, which occurred southeast of the Salton Sea.
The majority of the quakes occurred within about an hour of each other, joining about 50 small quakes recorded in the area over the past six days, according to Jennifer Andrews of the Caltech Seismological Laboratory. Andrews said the swarm occurred in the southern section of the Brawley Seismic Zone, one of the most active areas in all of California.