ShakeAlertLA

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About the city. The city of Los Angeles collects large volumes of data and shares it with public and private organizations and individuals, who can use this data for various applications.

Goal

ShakeAlertLA is designed to give smartphone users a warning, with sound, of earthquakes of 5.0 magnitude or larger, a few seconds or more before the shaking begins.

Implementation period. The USGS began the testing of public notification in California in October of 2019.

Fact

Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of earthquake risk is concentrated on the West Coast of the United States. In the next 30 years, California has a 99.7% chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10% chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

Solutions

The app depends on hundreds of sensors that collect data around geologic faults. When the sensors detect strong enough seismic activity, a notification is pushed out to users’ phones. The farther that app users are from the quake’s epicentre, the more advance warning they are likely to receive. Those very close to the epicentre may not be alerted until the shaking has already begun. While the ShakeAlertLA app is specific to L.A. County, it uses open-source technology that could be used to develop similar apps elsewhere.

Challenges

The city described the release as a pilot, but some of the early users left reviews complaining that the iPhone app crashed. A city representative said on January 4 (2019) that the city was working to debug the app and would release updates shortly.

The smartphone app failed to send out notifications when the Ridgecrest earthquakes rocked the region on July 4 and 5. Later Mayor Eric Garcetti announced that that city’s earthquake-warning app, ShakeAlertLA, is being fine-tuned.