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Hey ShakeAlertLA: Where's The Earthquake Alert App For The Rest Of SoCal?

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Do people outside L.A. have ShakeAlertLA envy? Even though our local earthquake alert app sat silently on our phones through not one, but two major earthquakes in the past week?

KPCC listener Raymond Cheung asks: "Why is there only one smartphone app available based on the ShakeAlert platform, and why is it only for L.A. County residents?"

Cheung said the L.A. taxpayers who funded the app often travel to neighboring counties and should have access to alerts there, too.


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The answer to the question has a lot to do with how it was developed.

When Mayor Eric Garcetti first took office, he set a goal of making Los Angeles a more earthquake-resilient city. That doesn't mean buildings don't get damaged in a big earthquake, but it does mean making changes that make the city as survivable as possible.

One of those changes was accelerating the development of a system that could warn people when an earthquake struck and give them a critical few seconds to take cover or brace for the shaking.

The ShakeAlert system is based on a network of hundreds of sensors placed along earthquake faults up and down the West Coast. There are more in areas of concentrated populations, fewer in the less-populated areas.

"The biggest limiting factor in terms of how quickly the system has been developed and how quickly it has rolled out is simply whether or not you have enough sensors in the ground," said USGS seismologist Sara Minson.

Los Angeles invested $6 million to add more sensors that feed information to the USGS system. The city also used funding from a $260,000 grant from the Annenberg Foundation to develop the ShakeAlertLA app with AT&T.

When it was first available for download Dec. 31, 2018, it was the nation's first publicly available earthquake early warning mobile app, the mayor's press release said.


There's not a public timetable for this yet, but the city does in fact intend to make the source code for the app available to other jurisdictions, a city spokeswoman said.

It's still early days, after all. The app's first big test came in the past week with the 6.4 and 7.1magnitude quakes in the Ridgecrest area. The system worked as designed, but the thresholds for notifying the public will be adjusted lower so that a similar pair of earthquakes and even some smaller ones would generate an alert.

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Los Angeles is in talks with officials from neighboring counties about getting the app, or at least the open source code that powers it, a city spokeswoman said.

In the meantime, the USGS needs funding to get more sensors planted in more earthquake faults to make the system more robust throughout California and other western states.

That's why Rep. Adam Schiff (D-Glendale) is calling on Congress to spend millions more dollars to add to the system of sensors. A House bill to add $25 million to build out the system goes before the Senate soon for a vote. That's about three times what President Donald Trump's budget had suggested be spent.

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