Most Californians know that sinking feeling.
The ground shakes, and you startle and concentrate. For a moment, Your mind considers the possibilities: Is a truck passing by? Is someone dropping a heavy object on the ground?
However, the truth soon becomes apparent: Earthquake!
For centuries, people living in earthquake-prone areas have experienced seismic movement in this way. But in the last few years, technological innovation has created another option: an alarm on your smartphone that gives you a few precious seconds to prepare for an earthquake.
California launches free earthquake early warning service Apps About five years ago. In 2024, after various improvements, a series of moderate earthquakes, and widespread use, the network will finally come into its own.
More than 5.4 million early warning alerts were issued on Tuesday. Earthquake of 5.2 magnitude The earthquake struck in Kern County, about 18 miles southwest of Bakersfield and 14 miles northwest of the unincorporated community of Grapevine.
“The heartbeat definitely speeds up, and the adrenaline starts pumping very quickly, no matter what,” Jennifer Lazo, chief of the innovation and technology division at the Los Angeles Department of Emergency Management, said of receiving an alert. “But understanding what the noise means, how to quickly see the message and then taking action immediately, I think, is what’s most important.”
Lazzo got the alert on her phone Tuesday night as she stood with her mother in the lobby of the Hollywood Pantages Theater during a show intermission. She told her mother to stay seated until they were sure the quake wasn’t too big.
She and her mother didn’t feel much of a jolt, but when they returned to their seats they realized many people in the audience had felt more of a tremor.
This was the third time in the past year that many Southern Californians received a ShakeAlert warning. Many are amazed at the technology’s ability to warn them before they feel the shaking, as was the case with the July 29 Mojave Desert earthquake, which was very powerful. So big it’s a little scary But it won’t cause any significant damage.
“It’s great that we have a number of earthquakes … ‘big enough’ so that we can use the system” and “give people a chance to get comfortable with earthquake early warning,” said Robert de Groot, operations team leader for the U.S. Geological Survey’s ShakeAlert system, which produces the alerts that are distributed to various apps. “That’s really important.”
Scientists want people to get used to these warnings, and they hope they will become part of life in California and other earthquake-prone areas of the West Coast.
People reported getting a few seconds of warning before the quake was felt on Tuesday in many locations, including Anaheim, Long Beach, Pasadena, Redondo Beach, the San Fernando Valley, the San Gabriel Valley, Ventura and West Los Angeles.
A Redondo Beach user received the alert Tuesday via MyShake, which also records past earthquakes.
(Renee Garcia)
Some people reported receiving an earthquake alert 30 to 45 seconds before the quake struck. They may have felt the first aftershock – a 4.5 magnitude quake that struck less than a minute after the 5.2 magnitude quake.
In West L.A., De Groot said his wife first saw the alert on her phone and said, “What is this Kern County thing?” He said the initial warning predicted a light shaking would hit their home, and maybe 15 seconds later, they felt it — a shaking he described as “very light back and forth” for about four seconds.
The largest quake was Tuesday’s 5.2 magnitude quake. It is the largest earthquake to hit Southern California in three years. Other recent earthquakes in which many people reported feeling shaking include the July quake Magnitude 4.9 Earthquake centered in the Mojave Desert and last year’s earthquake Magnitude 5.1 earthquake near Ojai in Ventura County, which infamously killed on the same day Major hurricanes Weak Hurricane Hilary threatens the area.
Within seconds of Tuesday night’s quake, the Earthquake Early Warning System estimated the magnitude at 6.0, and a short time later lowered it to 5.7. The USGS website said the quake had a magnitude of 5.3, but later lowered that to 5.2.
Of course, there were people who received the alert but didn’t feel the tremor, while those living closer to the epicenter — within 20 miles of the quake’s origin — felt the tremor before they received the alert.
But this is expected: it’s a compromise, so that alerts can be sent to as many people as possible before an earthquake is felt.
The system works on a simple principle: Vibrations from earthquakes travel through rocks at the speed of sound—less than the speed of today’s communications systems. For example, a magnitude 7.8 quake originating in the Salton Sea along the state’s longest fault, the San Andreas, would take more than a minute to be felt 150 miles away in Los Angeles.
However, many people are not getting alerts because they do not have an earthquake early warning app installed on their phones. While Google’s Android operating system comes with a built-in app, Apple’s iOS system for iPhones does not have this app.
Over 517,000 alerts sent MyShare Users, According to the governor’s office, and de Groot said Google sent more than 4.9 million alerts to Android users.
Like Amber Alerts, wireless emergency alerts are available to mobile phones without a special app — but only for nearby strong earthquakes.
(Robert de Groot / US Geological Survey)
How to get advance information about an earthquake
Those who have an iPhone can download and receive earthquake early warnings for free. MyShake The app, developed by UC Berkeley and provided in partnership with the California Governor’s Office of Emergency Services, alerts users in California, Oregon and Washington. San Diego County also offers the service for free SD Emergency The app, which includes the ShakeReadyDSD earthquake early warning tool.
People who don’t have smartphones or haven’t installed advance warning apps can still get earthquake alerts on their cellphones — but only for ones that have a high intensity or high level of shaking projected to their location. Those alerts are sent through the Wireless Emergency Alert System, which is similar to Amber Alerts.
Android phones and phones with the MyShake or ShakeReadYSD apps installed have the lowest threshold for earthquake early warning: they are set to trigger an alert if the quake is predicted to have a magnitude of 4.5 or higher and the vibration intensity at the phone’s location is expected to be greater than 1000. “weak” — defined as level 3 on the Modified Mercalli intensity scale.
People who don’t have Android phones or the app can also receive early warnings on their own through the Wireless Emergency Alert System. Its limits, however, are a little more conservative: Alerts are triggered on cellphones only when the earthquake is expected to have a magnitude of 5 or greater and the shaking is expected to be “light,” defined as level 4 on the Mercalli scale.
An unknown number of phones received wireless emergency alerts Tuesday night.
People will remember to download the earthquake early warning app Issued There was an app launched by the city of Los Angeles on New Year’s Eve in 2018 – ShakeAlertLA – but that app was shut down at the end of 2020.
Scientists have urged California residents to download early warning apps, and said it’s not a bad idea to have more than one way to receive alerts on your phone. MyShake It is available for both Apple’s iOS and Android.
“It’s worthwhile to set things up. It’s worthwhile to get this technology and use it,” de Groot said. “It works … It gives us a chance to live a comfortable life with early warning of earthquakes.”
Other Nation Early warning systems are in operation in several countries, including Japan, Mexico, Taiwan and Turkey. They are a part of life in Japan: schoolchildren are trained to drop, cover and hold on as soon as they hear an alert; TV shows are interrupted by a familiar bell in which an announcer details the expected shaking; and cellphones automatically transmit audible alerts.
on a Thursday morning, a Earthquake of 7.1 magnitude The quake was reported off the east coast of southern Japan’s main island of Kyushu, sparking concerns of a possible tsunami as officials were surveying the area to assess damage.
There was no serious damage, and no tsunami is expected in California, according to regional news media. The epicenter of that quake was about 550 miles southwest of Tokyo and about 14 miles southeast of Miyazaki.
Taiwan’s successful early warning system attracted much attention in March, and many people expressed surprise. Television journalist Who warned viewers about the strongest tremors of the 7.4 magnitude earthquake before it reached his studio, and continued to broadcast the warning even as he struggled to stay standing and ceiling lights collided with each other.
Initial call for California earthquake early warning system launched More than a decade ago. Officials say it’s now clear that years of investment, made possible by support from elected officials in Washington and Sacramento, is finally bearing fruit.
“Our investments in cutting-edge, innovative technologies are paying off,” said Governor Gavin Newsom. “Efforts like these have helped us get the critical seconds between when the alert hits Californians’ mobile phones and when the ground starts shaking.” MyShake App Release In 2019, a statement said The statement was issued on Wednesday.
“Californians, I encourage you to download the app,” he said. “It could save lives!”
It can be a little intimidating to receive the first alert, but this system can help Californians be prepared for major earthquakes.
It’s been exciting to see the alerts work in real life, not just as a theoretical exercise, said Lazo, of L.A.’s Department of Emergency Management.
“This shows that there’s a lot of rigorous use of science that’s really going to have an impact on the public and hopefully keep people safer,” he said. “And that’s a great thing to see. This is a new frontier for us in earthquake response.”
Times staff writers Luke Money, Joseph Serna and Ruben Vives contributed to this report.
