For the second time in two days, a major earthquake rocked Southern California, centered near the town of Ridgecrest, about 113 miles northeast of Los Angeles. The epicenter was located in the Mojave Desert. The July 5 quake struck at 8:16 p.m. PT, and caused shaking for about 40 seconds, according to a report by NBC San Diego.
Initial reports put the magnitude of the quake at a magnitude of 7.1, according to a report by The Los Angeles Times.
On Thursday, July 4, the same area was hit with a quake that measured 6.4, making it the most powerful quake in at least 20 years to strike Southern California, according to CNBC. But that mark was eclipsed less than 34 hours later by the 7.1 quake.
Had the quake struck a heavily populated area, the damage could have been devastating, though damage reports had not yet come in as of 9 p.m. local time. The Friday quake was more powerful that the January 17, 1994, Northridge quake that measured 6.6, but that one struck an urban area in the San Fernando Valley area of Los Angeles, killing 57 people and caused an estimated $20 billion in damage, according to a History account.
Other reports said that Friday’s Ridgecrest quake measured a 6.9 magnitude, after a revised measurement by the United States Geological Survey, according to a Twitter report by ABC 15.
These were the coordinates for that 7.1 earthquake, according to the USGS twitter account. It would have been absolutely devastating if it were in an urban area, and no doubt dangerous for the people there. pic.twitter.com/oaFoPkPujn
— Matt Pearce ???? (@mattdpearce) July 6, 2019
By 9 p.m., the USGS had recorded 14 separate aftershock quakes in the area, including a 4.7 temblor near Little Lake, California, followed six minutes later by a 4.0 shock in the same location, and a 4.2 less than one minute after that.
In the city of Los Angeles, the L.A. Fire Department was conducting surveys for possible damage, dispatching helicopters and vehicles throughout the city, according to NBC San Diego.
According to seismologist Dr. Lucy Jones, posting on her Twitter account, the July 4 earthquake can now be classified as a “foreshock” before Friday’s massive 7.1 quake.
“This was…on the same fault as has been producing the Searles Valley sequence. This is part of the same sequence,” Jones wrote.
Jones went on stay in a subsequent Twitter post that seismologists often say that any quake has a one-in-20 chance of being followed by a larger quake.
“This is that 1 in 20 time,” she wrote.
Following Thursday’s 6.4 Ridgecrest earthquake, seismologist Egill Hauksson told The Los Angeles Times that aftershocks from that quake would likely “go on for months, if not years.” Early on Friday morning, the same area experienced a 5.1 quake, but that and all subsequent aftershocks were only leading up to the 7.1 quake that struck on Friday night.
Jones warned on her Twitter account that an an aftershock measuring above 6.0 was “quite possible,” because the quakes have been part of a “sequence.”