CA Quake Alert System Lauded After Warning Millions: 'Well Done!'

SOUTHERN CALIFORNIA — Seconds after a 5.2 earthquake rattled Southern California, millions of smartphones lit up with blaring alerts, warning residents to take cover.

The temblor, which was centered just south of the Elsinore fault zone near San Diego County's town of Julian, struck at 10:08 a.m., according to the U.S. Geological Survey. The quake had a depth of about 8.3 miles.

The shaking was felt in Orange, Riverside, and San Bernardino counties and as far away as Los Angeles.

Alerts were sent to mobile phones across the region, warning area residents to "drop, cover, hold on!"

"I live in Lake Forest and got the alert as the house was shaking. I was actually impressed to get the alert during the quake," reader John Vavrina told Patch.

But not everyone had the same experience.

"I did not get an alert. Not sure why. My husband got one and we live in the same house," reader Cary Levy Wagner said.

Some Patch editors who live throughout the Southland reported getting the alert.

Statewide Editor Kat Schuster felt the quake while dining in a Palm Desert restaurant, where a chorus of phone alarms erupted across the room. Los Angeles Editor Paige Austin felt mild shaking in Big Bear and also received the alert. Riverside County editor Ashley Ludwig received the alert moments before the quake. San Diego Editor Kristina Houck said the quake shook her East County home strongly. Houck received the alert after the shaking had stopped, while Schuster got hers mid-quake and Austin got one before the quake.

According to the state, millions of Californians got an early notification on their phones.

Some 700,000 phones in the affected area got a notification through the MyShake app while millions more received alarms through wireless emergency alerts and Google alerts, according to the California Governor's Office of Emergency Services.

“Warning Californians before earthquakes strike can save lives,” said Cal OES Director Nancy Ward. “The MyShake app is doing what it is designed to do, and we encourage all Californians to download it today."

Just after the temblor, more than 27,000 people downloaded the MyShake app, which Gov. Gavin Newsom launched in 2019 and powered by the United States Geological Survey.

It's the nation's first state earthquake early warning system.

We asked Southern California Patch readers on Facebook if they got the alert. Here's what some of them said:

"We received the alert. However, we were on the freeway. My daughter in LA though received it also and said she felt the quake a few seconds later."

"I'm in Yucaipa and I got the alert on the MyShake app about 5 seconds before feeling the quake."

"I received the alert on my Apple Watch about 10 seconds before the quake."

"Received the Alert and it was before the quake"

"I felt/heard it first sitting in my upstairs office area. Got the alert while moving to door frame."

"I got the alert a few seconds after the earthquake"

"I got it before the earthquake and wondered if it was real."

"I got the alert and by the time I grabbed my phone which was right beside me, the shaking started. I am in Santee."

"I got it two seconds before. Just enough time to be sure I was not near glass and could cover my face."

"Got it during the quake. My first thought was, 'Thank you, Captain Obvious.'"

"I got the alert while on my walk at Trilogy. I looked around, waiting to see what was going to happen. I never felt it but folks here in their homes said they felt it. I’m very grateful for the Alert."

"I received the alert right before the quake. I was at Rancho Springs Hospital."

Many more throughout Southern California applauded the notification system on X:

"Excellent work on the fast alert. Impressive timing."

"That was awesome! GREAT EARLY WARNING!!! I got the alert on my phone near downtown San Diego several seconds before the primary wave hit."

"We felt it pretty good in San Juan Capistrano. The alert was going off as the earthquake was happening."

The original ShakeAlert notice was sent to cell phones throughout much of Southern California, initially putting the magnitude of the quake at 6.0, but the USGS later downgraded it to 5.1, then revised it again to 5.2.

At least six smaller aftershocks with magnitude readings of less than 3.0 happened within the 10 minutes following the quake, according to the USGS. Another quake near Borrego Springs registered 3.5.

A 3.9 magnitude quake was recorded at 11:23 a.m. near Julian.

"San Diego experienced a strong earthquake centered near Julian," San Diego Mayor Todd Gloria said on social media. "There's no known visible or major damage to the city so far and I'm in communication with local, state and federal officials."

The California Governor's Office of Emergency Services said the agency was working with local agencies to assess any possible damage or impacts from the quake. The governor's office issued a statement saying Gov. Gavin Newsom had been briefed on the temblor.

"The state is coordinating with local authorities to assess any damage and if emergency response is needed," the office said.

Seismologist and Southern California earthquake expert Lucy Jones said the quake appeared to have been felt "over a very large area," stretching into Los Angeles. She said given the size and depth of the quake, it was unlikely to cause any series damage "to a normal California building," although it may have knocked some items off shelves.

"There shouldn't be structural damage," she said. "If there is, it's in a pretty bad building."

Caltrans, however, warned drivers on Monday to watch out for obstacles in the roadway after boulders fell onto state Route 76, east of East Grade Road near the Lake Henshaw area.

"Caltrans crews are out assessing the highway infrastructure for any damage from this morning's earthquake," the agency said on social media.

The Southern California Earthquake Data Center notes that the main trace of the Elsinore Fault has experienced only one notable event greater than magnitude 5.2 — a magnitude 6.0 earthquake in 1910 near Temescal Valley. That quake caused little damage and left no visible surface rupture. However, the fault's southeastern extension, known as the Laguna Salada Fault, ruptured in a magnitude 7.0 event in 1892.