ShakeAlertLA App To Keep Residents Better Informed

LOS ANGELES, CA — This summer, SoCal has had its share of shake, rattle, and roll during the Ridgecrest earthquake swarm. Still, the city's ShakeAlertLA app, designed as an early notification earthquake system, drew criticism for not notifying users during the July 4 and 5 earthquakes.

On Wednesday, the city announced the app will now send alerts for smaller quakes.

Starting mid August, the system will alert residents of earthquakes at magnitude 4.5 or larger, Los Angeles Mayor Eric Garcetti said, in a meeting with CalTech and the United States Geological Survey.

The previous threshold was magnitude 5.0.

"What this means is simple -- Angelenos will get more alerts about earthquakes," Garcetti said.

Every day we are communicating the importance of preparedness, so that every Angeleno has the tools and resources they need to build a better life, and then protect that life when disaster strikes, according to Garcetti. Now, updates to ShakeAlertLA will result in an even more responsive application, making our city stronger and our families safer.

But given the widespread shaking that occurred, many residents complained about the lack of any warning from the app. So officials said Wednesday they have agreed to lower the threshold for notifications.

"We wanted to balance the need to let people know of earthquakes and also to make sure that we didn't cause too much chaos, that people weren't running out of crowded theaters or driving off the sides of the road just because they knew an earthquake was coming," Garcetti said.

The USGS ShakeAlert Earthquake Early Warning System for the West Coast detects significant earthquakes quick enough that ShakeAlerts can reach people a few seconds before shaking starts.

"The USGS, through its scientific expertise, creates ShakeAlert earthquake early warnings, but in order to be successful, our public and private partners must develop technologies to use and distribute the alerts," said Doug Given, the USGS' earthquake early warning coordinator.

ShakeAlertLA was developed in collaboration with USGS, AT&T and The Annenberg Foundation to combine USGS sensor network with mobile app technology, according to the Mayor's Office. It launched at the end of last year.

When people receive a ShakeAlert notification, they are advised to take protective action, such as drop, cover and hold on.

More information can be found at www.shakealert.org

This animation shows preliminary results from precise relocation of the Ridgecrest foreshock sequence, up to the the time of occurrence of the M 7.1 mainshock. Full details at: https://t.co/Gm3GuSPt0s pic.twitter.com/RfIijTiHfu
— USGS (@USGS) July" class="redactor-linkify-object">https://twitter.com/USGS/statu... 12, 2019

City News Service, with Patch editor Ashley Ludwig