6.4 Earthquake — And Dozens Of Aftershocks — Rock Our SoCal July 4th Holiday
A magnitude 6.4 earthquake struck a remote area of the Mojave Desert Thursday morning as Southern Californians celebrated the Fourth of July holiday. The shaking was felt throughout a wide region and appears to have done damage — including setting off some fires — closer to the epicenter.
The quake was initially reported as a 6.6 magnitude, which would have put it on par with the 1995 Northridge quake, which was centered in a far more populated area.
The USGS puts the epicenter southwest of Searles Valley, near the city of Ridgecrest near Death Valley. Considered a "strong" earthquake under USGS standards, the temblor was felt strongly here in the L.A. area, even though the epicenter was more than 100 miles to the northeast.
The initial quake was reported just after 10:30 a.m. and has been followed by dozens of aftershocks, a number of them magnitude 4.0 or greater. There could be up to 700 magnitude 3 or greater aftershocks over the next week, according to the USGS. The average earthquake of this size produces an aftershock as large as a 5.4, with about 10 aftershocks 4.4 or larger.
Dr. Lucy Jones, speaking at a news conference at Caltech, said there was about a 9% chance of a quake greater than the original 6.4 magnitude over the next week. She added that the rate of aftershocks has already slowed.
Geologists are warning that an aftershock magnitude 5.0 of greater remains very likely, but they cautioned that any predictions of an exact time were not reliable.
Via @USGS the probability of a 7.0 or greater in the next week is 1%.— Jacob Margolis (@JacobMargolis) July 4, 2019
6.0 or greater is 11% (5% one will hit in the next day).
5.0 or greater is 67%.
There could still be big quakes! pic.twitter.com/Macca5gTJ1
WHAT HAPPENED WITH THE EARTHQUAKE APP?
The quake did not set off a relatively new app that is designed to give people as much as a 45-second warning ahead of a sizable earthquake. The lack of warning from the city's ShakeAlertLA app left some people confused. But according to the city and scientists, the system worked as intended. The level of shaking forecast for Los Angeles was not strong enough to trigger an alert.
The reaction to the lack of such a warning has already prompted the city to say that they'll lower the threshold for alerts on the app. The USGS also responded.
The #ShakeAlertLA app only sends alerts if shaking is 5.0+ in LA County. Epicenter was 6.4 in Kern County, @USGS confirms LA's shaking was below 4.5. We hear you and will lower the alert threshold with @USGS_ShakeAlert— City of Los Angeles (@LACity) July 4, 2019
The @LACity #ShakeAlertLA app sends USGS ShakeAlerts to people in @CountyofLA at M5.0+ for areas that could experience potentially damaging shaking. Estimated shaking for @CountyofLA was non-damaging and #ShakeAlertLA performed as designed during today's M6.4 earthquake.— USGS ShakeAlert (@USGS_ShakeAlert) July 4, 2019
This was the first significant quake to erupt since the app was released earlier this year, according to Jones.
Seismologists at Caltech and the U.S. Geological Survey were mystified at the lack of a notification in the 48 seconds it took for the shaking to reach L.A.
WAS THERE DAMAGE?
Close to the earthquake's epicenter, there have been reports of damage. A state of emergency was declared in the city of Ridgecrest as of Thursday afternoon, according to Mayor Peggy Breeden. The estimated economic damage is in the tens of millions and up to 100 million dollars, according to the USGS.
The Kern County Fire Department reported that the Ridgecrest Regional Hospital was being evacuated. The decision was made out of an abundance of caution, according to the hospital's CEO.
"We have approximately 25 patients that need to be transferred to other facilities," Ridgecrest Regional Hospital CEO Jim Suver said. He added that they were continuing to see emergency patients in an outside triage center.
The LAPD said there had been no reports of serious damage to city infrastructure as of late Thursday morning. There were also no reports of injuries in L.A., according to a statement from the department. They said they were working with the Los Angeles Fire Department and other city agencies.
At this time, the LAPD has not received any reports of damage or calls for service within the City of Los Angeles related to the #earthquake. Remember, 911 is only to report emergencies. This was a strong one, and a good reminder to be prepared 🔗 https://t.co/fURDNcMhhQ— LAPD HQ (@LAPDHQ) July 4, 2019
The L.A. Department of Water and Power believes that a damaged water main in the 6400 block of Wilshire may be related to today's earthquake. There were also three limited power outages that may be related.
The fellowship hall ceiling at First Baptist Church in Trona, near Ridgecrest, caved in, according to Pastor Larry Cox.
"We had a lot of our things come off the shelves," Cox said. "The ladies' bathroom ceiling came down. We had two broken windows."
Cox said there were also some water main breaks, the power went out, and there was some visible road damage. He said the damage will likely take about $3,000 to repair.
Firefighters were sent to Trona to check for any immediate hazard in the area, according to San Bernardino County Fire Public Information Officer Jeremy Kern.
"We did find that there were some cracks within the roadways upwards of about 4 inches," Kern said. "We also did find some rockslides, larger boulders that have rolled down into the roadway."
They're working with California Highway Patrol to clear up the debris, but drivers are still able to enter and exit the area, Kern said.
Caltrans District 9 Maintenance crews make repairs to cracks along SR 178 near Trona within an hour after 6.4 quake in Ridgecrest #Caltrans8 @Caltrans9 @CA_Trans_Agency @CaltransHQ pic.twitter.com/FpryJoWVos— Caltrans District 8 (@Caltrans8) July 4, 2019
NOT A BIG ONE
The earthquake was not along the San Andreas fault, the one we're all watching while thinking about the Big One.
Earthquakes like this are the norm in California historically, but we have had an extended quiet period in recent years. Earthquakes of this size should be expected about every five years.
Thursday morning's earthquake was on the Little Lake fault. The last time there was major activity on that fault was a swarm in 1982, with the largest being a 5.2 quake. Today's earthquake was likely powerful enough to break the earth's surface.
M6.4 on a strikeslip fault about 10 miles from Ridgecrest. Not the San Andreas fault. It is an area with a lot of little faults but no long fault— Dr. Lucy Jones (@DrLucyJones) July 4, 2019
Southern California could be hit by an earthquake 125 times stronger than the one felt Thursday morning, with much more populated areas feeling the impact.
The San Andreas is the large fault along the bottom of this fault map:
No, it was not on the San Andreas. First picture is of the shake map. You can see the epicenter about 150 miles from LA / north east of Bakersfield. Second is a fault map. The arrow points the the San Andreas. The circle is where the epicenter was. pic.twitter.com/asKQDt4CNG— Jacob Margolis (@JacobMargolis) July 4, 2019
Get ready for the next major earthquake. Listen to our podcast: The Big One: Your Survival Guide
People from throughout Southern California felt the earthquake. Lena Nguyen, who lives in Long Beach, said that she was sitting in her living room when she felt it. As she felt the intensity increase, she grabbed her dog and ran out of the house.
The quake was also felt by our reporters.
Kyle Stokes was in his Silver Lake apartment when the shaking started. He said that he didn't feel it at first, but noticed what sounded like rain on the roof — before realizing that his picture frames were shaking, with shaking lasting for about 10 seconds.
Libby Denkmann felt a slow swaying in Highland Park as the house shifted back and forth, describing it as feeling like they were dizzy or unsteady on their feet.
In California, about 50 miles from the epicenter, Steve Colerick was vacuuming his pool when the earthquake stuck — waves started to slosh around. He didn't see any damage locally.
Theresa Grimshaw's dogs woke up when the earthquake hit in California City, but they were back asleep 30 minutes later. "Just some rumbling and gentle shaking," she said, adding, "we've been through worse."
The shaking was felt from Long Beach to Las Vegas. People from all over shared their experiences on social media:
My dads liquor store in Ridgecrest (11 miles from the earthquake) 🥴 pic.twitter.com/4RC0mY3eha— Zomo (@zomo_abd) July 4, 2019
EARTHQUAKE! Took this video 10 seconds after. My chandeliers are still shaking! pic.twitter.com/Ta72ZgbgPd— Lisa Guerrero 💃🏽 (@4lisaguerrero) July 4, 2019
We felt a long rolling type earthquake here in Altadena. https://t.co/ROvU4EQvYT— L.A. County Sheriff's Altadena Station (@ALDLASD) July 4, 2019
I can chart how long I have been in L.A. by my reaction to earthquakes.— Matthew Federman (@matthewfederman) July 4, 2019
Years 1-5 Jumps out of seat
Years 5-15 Stands, looks around cautiously
Years 15- Sits, continues typing. Says aloud "Earthquake."
This story was originally published at 10:58 a.m. and was updated throughout the day as new information became available. An earlier version incorrectly said that Ridgecrest was in Death Valley. The city of 28,000 is southwest of the national park.
With contributions from Emily Guerin, Jacob Margolis, Megan Erwin, Megan Garvey, Lita Martinez, Sharon McNary, Itxy Quintanilla, Libby Denkmann, and Kyle Stokes.