Hundreds of aftershocks rumbled in Southern California on Friday, the day after the region was rocked by the strongest earthquake in two decades, igniting fires, triggering a hospital evacuation and raising concerns about an even more powerful jolt.
Most of the aftershocks ranked in the magnitude 2-to-3 range, with a few in the magnitude 3-to-4 range, well below the Fourth of July's magnitude 6.4 earthquake centered near Ridgecrest, an inland Kern County city about 150 miles northeast of Los Angeles.
"We're getting aftershocks every few minutes. There are hundreds of them," Randy Baldwin, a geophysicist at the U.S. Geological Survey's National Earthquake Information Center in Golden, Colorado, said early on Friday. "There's a chance of some larger ones, in the magnitude 5 range."
One aftershock struck even as Ridgecrest Police Chief Jed McLaughlin briefed news reporters about the emergency response to the earthquake on Thursday afternoon PDT.
A 5.4-magnitude aftershock rattled the nearby Searles Valley area Friday morning, less than 24 hours after the major earthquake. The aftershock occurred just after 4 a.m. about 10 miles west of Searles Valley, according to USGS data. It was the strongest of the more than 200 that followed Thursday's seismic event.
Lucy Jones, a California-based seismologist, tweeted that the actual probability of the Big One, a far stronger earthquake, is about 2 percent per year.
An individual's chances of being in a car accident today are about one in 7,000, Jones said, adding "I still wear my seat belt every day."
Although Thursday's earthquake was felt in Los Angeles and even in Las Vegas, more than 250 miles northeast of Los Angeles, it caused no damage in those locations. The earthquake was far enough away from the dangerous and well known San Andreas fault "that any impact on the system will be minimal," Jones told the Los Angeles Times.