Millions Of People In California Can Now Get Earthquake Alerts On Their Phones Seconds Before The Ground Shakes

Millions of people in Southern California can now receive alerts on their smartphone seconds before shaking from an earthquake is about to strike, marking the first time large numbers of Americans will have access to such early warning technology.

Launched this week, ShakeAlertLA will alert users when a magnitude 5.0 or greater earthquake has been detected in Los Angeles County.

"Earthquakes are a matter of when — not if," Los Angeles Mayor Eric Garcetti tweeted Wednesday, announcing the release of the mobile application, which was developed with AT&T as part of a pilot program with the US Geological Survey.

It's the first earthquake early warning application to be widely released to the public in the US after decades of funding challenges that put the country behind other nations, like Japan and Mexico, which have built their own early warning systems.

Garcetti encouraged other cities to follow Los Angeles' lead.

"We weren't looking to be the first, we weren't looking to be the only — we want all of California, all of this country, wherever there’s earthquakes to use this," he said during a press conference Thursday. "Somebody had to develop it. We stepped forward and we did."

A separate mobile app, QuakeAlert, has been available to about 1,000 beta testers and will be released to 100,000 users across California later this year, Josh Bashioum, founder of Early Warning Labs, the Santa Monica–based company that developed the app, told BuzzFeed News.

Both applications rely on a USGS network of 800 ground sensors located up and down the West Coast that can detect shaking and trigger the alerts.

The early warnings are generated with data from the sensors by tracking an earthquake's "P waves," which travel faster through the ground than the more violent "S waves" that cause the shaking. The amount of lead time people receive depends on how far they are from a quake's epicenter.

"There's a physical limitation if you're right on top," Robert de Groot, a staff scientist at USGS Earthquake Science Center, told BuzzFeed News. "You will still get a shake alert, but it will likely arrive while the shaking is going on or after."

Government agencies and private companies hope to continue expanding access to these cellphone-based alerts that could potentially save scores of lives in temblor-prone cities in California, Oregon, and Washington.

"The opportunity to have maybe a second or two or maybe a few seconds to do something about it is of great value," de Groot said.

The USGS is also developing an alert system using the same delivery method as Amber Alerts, which are transmitted through a federal system and don't require the download of a special app.

One challenge with the federal system, however, is that it may not be fast enough to send earthquake warnings in advance. De Groot said the Los Angeles application will help the agency test how delivery times change as the number of users increases.

"The idea is to get out shake alerts to everyone residing on the West Coast," de Groot said. "That's going to take some time, but this is going to allow us to learn how to do this with very large amounts of people."

Early warning systems have been credited with saving lives in other countries. When a magnitude 7.2 earthquake struck Mexico's southern region last February, the app SkyNet sent notifications to residents' cell phones, in some cases, as much as 75 seconds before the shaking started.

In Japan, earthquake warnings appear on all TV broadcasts when a temblor is detected.

The estimated cost of completing the early warning system is $39.4 million, while the annual cost to operate and maintain the system is estimated $28.6 million, according to a recent USGS report.

Congress initially allocated just $5 million for the system in 2014 and has since gradually increased funding. Last year, lawmakers allocated $22.9 million for the warning system.

Rep. Adam Schiff, a California Democrat who has long pushed for federal funding for the system, congratulated Los Angeles on the launch of the app Thursday, calling it "another major milestone."

"By downloading this app on their phones, Angelenos will be able to receive a warning before the shaking starts, saving lives when the 'big one' hits," Schiff said in a statement. "I’ve been proud to work with my congressional colleagues to secure over $45 million to date in federal funding to build the system, but the effort could not be successful without great local partners."

DeGroot said at the end of 2018 about 50% of the network's planned 1,675 sensors had been installed so far.

"Completing the system is really dependent on getting the money that we need to do it," he said. "If things proceed the way they should we're probably looking into the early 2020s for a complete system."

Garcetti on Thursday called on lawmakers in Washington, DC, to continue funding the project, saying the technology is critical to saving lives.

"This works and we need it," Garcetti said.