Environment & Science

The Ridgecrest Earthquake Didn't Trigger The ShakeAlert LA App. Here's Why.


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Many Angelenos have the ShakeAlert LA app on their phones. It’s supposed to notify you when shaking from an earthquake is coming your way. But the app sent out no alert after Thursday's’ earthquake near Ridgecrest.

CalTech seismologist Robert Graves says the app is set to warn Angelenos only if the local shaking is higher than a magnitude of 5.0 in Los Angeles County. While Thursday's earthquake measured 6.4, it had dropped intensity in the 48 seconds it took to reach Los Angeles. Officials say they'll lower the threshold for alerts in the future.