The odds that Southern California will experience another earthquake of magnitude 7 or greater in the next week are now nearly 11%, according to preliminary estimates from seismologists.
And the chances that a quake will surpass the 7.1 temblor that struck near Ridgecrest on Friday night are roughly 8% to 9%, said Caltech seismologist Lucy Jones.
"There's about a 1 in 10 chance that we could have another 7 in this sequence," she said.
More likely is that the Owens Valley will experience another temblor of magnitude 6 or greater. The odds of that are slightly greater than 50-50, Jones said. And more quakes of magnitude 5 or greater are a near certainty.
"It would be extremely unusual if we didn't have another 5" over the coming week, Jones said.
The 7.1 quake on Friday night was about 8 times larger than the 6.4 quake on Thursday morning, said Robert Graves, a seismologist with the U.S. Geological Survey in Pasadena.
Though such quakes would be more likely to occur in the next few days, the shaking could continue for quite some time.
"A magnitude 7 usually has aftershocks that last for years," Jones said.
Jones said she could not recall a pattern of earthquakes in California where a 6.4 foreshock was followed by a 7.1 event, only to be followed by an even bigger quake.
But that doesn't mean it can't happen, she cautioned.