Earthquake expert Dr. Lucy Jones says 5% of the time, the aftershock could be larger than the original quake.
SAN JOSE, Calif. (KGO) -- A 5.1 magnitude earthquake struck near San Jose Tuesday morning and was felt across the Bay Area. Dr. Lucy Jones, a seismologist at Center for Science and Society and research associate at Seismological Laboratory at Caltech, says aftershocks as strong as 4.0 earthquake are possible on the Calaveras Fault in the next 24 hours.
MAIN STORY: 5.1 earthquake strikes near San Jose, USGS says
According to Dr. Jones, 5% of the time the aftershock could be larger than the original earthquake.
She notes that the last major earthquake in the San Francisco Bay Area was a 6.0 in Napa.
There is chance of a larger earthquake on the Calaveras Fault over the next few days.
"The Calaveras moves more slowly, it has less of the total motion going on there than on the San Andreas, so it moves less often or releases less energy," she said. "But it seems to have the smaller earthquakes a lot more often. It's considered capable of a six and a half or so. But unlike the San Andreas, it's not going to have, you know, a magnitude eight."
Dr. Jones referenced the Ridgecrest quake in 2019, when there was 6.4 quake followed by a 7.1 earthquake the next day.
ABC7 News anchor Reggie Aqui asked Dr. Jones about the UC Berkeley-created MyShake app, and how he noticed on social media people that in San Francisco got the alert on their devices before the actual earthquake happened.
She said the earthquake early warning system is run off of the network-funded and operated through the U.S. Geological Survey, as Berkeley is one of the USGS partners.
"But what you have is that the same seismic stations that tell us what the earthquake is, are now able to give you the information so quickly, you can give it a few seconds before the shaking gets to your site," she said. "So in the Bay Area in San Francisco, because the waves had to travel up from south of San Jose, they would have would have had a decent amount of warning. But of course, if you were actually in Alum Rock, your shaking is what allowed the others to know."
She spoke live with ABC7 News following the quake. Watch the video player above to watch her full interview.
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