More Strong Quakes Expected In California

3,000 earthquakes since July 4, and more big ones likely coming 

Southern California could experience another sizable earthquake over the next week, seismologists said Saturday.

The U.S. Geological Survey has calculated a 27% probability the region will be hit by a magnitude 6 or greater quake in the coming days, according to Caltech seismologist Egill Hauksson.

“We're likely to see maybe one or two of those in the next week,” he said at a news conference.

The USGS estimates that the probability of a magnitude 7 or greater earthquake hitting within the next week has fallen to 3%, down from 6% on Friday.

“That probability is over the next week, but it is mostly packed into the hours and days after the main shock,” Caltech seismologist Doug Given said.

In other words, the probability that we will experience another earthquake of magnitude 6 or higher is dropping by the minute, he said.

“Every minute that ticks by, it becomes less likely,” he said.

The heightened seismic activity comes in the aftermath of a 7.1 magnitude quake that hit near the town of Ridgecrest, about 125 miles northeast of Los Angeles, on Friday night. That was preceded by a 6.4 magnitude earthquake in the same area the morning of the Fourth of July. Scientists are now calling that a foreshock.

Since the Fourth, Caltech seismologists have detected at least 3,000 smaller earthquakes.

Those include 340 earthquakes with a magnitude greater than 3, 52 with a magnitude greater than 4, and six with a magnitude greater than 5, Hauksson said Saturday.

In total, this earthquake sequence is expected to generate about 34,000 aftershocks with a magnitude 1 or greater over the next six months, he said.

This week’s earthquakes were the strongest to hit the area in 20 years. No deaths or major injuries have been reported, but homes and roadways were damaged, particularly in the Ridgecrest area.

Gov. Gavin Newsom has requested a presidential emergency declaration for the affected regions.

Ridgecrest Mayor Peggy Breeden said she encourages residents to take safety precautions over the next few days until the seismic activity subsides. She said the town shouldn’t suffer any long-term consequences from the last several days. She doesn’t believe residents will flee to other cities.