The recent aftershocks have been close to the Garlock Fault, a 160-mile strike-strip fault that runs northeast from the San Andreas Fault to the eastern Mojave Desert.
The Los Angeles Times spoke with U.S. Geological Survey research geophysicist Morgan Page about the increased activity near the Garlock Fault.
"Those are places we would be more concerned. Little earthquakes are telling us where big earthquakes are more likely," Page told the Times.
The aftershocks appear to be headed toward the Garlock Fault which is capable of producing an earthquake of a magnitude of 8 or more, according to the Times.
"Every earthquake actually increases the probability of more earthquakes. Earthquakes are like that … In general, if there are a lot of earthquakes going on, it's more probable for a large earthquake to go on," Page told the Times.
Small earthquakes do release pressure and prevent larger ones, but they also can redistribute the stress to other faults like the Garlock Fault.
In the meantime, California is spending more than $16 million to install thousands of quake-detecting sensors statewide that officials say will give utilities and trains precious seconds to shut down before the shaking starts.
Seismologists said a quake similar in size of the July 5 quake in a major city like San Francisco, Los Angeles or San Diego could collapse bridges, buildings and freeways, as well as spark devastating fires fueled by ruptured gas lines.
"We're going to have a magnitude 6, on average, somewhere in Southern California every few years. We've actually gone 20 years without one, so we have had the quietest 20 years in the history of Southern California," said seismologist Lucy Jones of the California Institute of Technology.
“That’s unlikely to continue on the long run,” she added. “Geology keeps on moving ... and we should be expecting a higher rate. And when it happens near people, it is going to be a lot worse.”
Despite the concern, the USGS maintains that the probability of a 7.1 or larger quake has fallen to less than 1%.
The Associated Press contributed to this report.
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