When two major earthquakes hit Ridgecrest earlier this month, many Angelenos looked to L.A.’s new ShakeAlert app and saw… nothing.
Experts explained the lack of alert was actually because the system performed as designed. The app was only supposed to alert residents about earthquakes that could cause significant damage to the L.A. area – not just shaking.
But after public outcry, officials agreed to lower the threshold for alerts. By the end of the month, Angelenos will receive alerts for local earthquakes above a 4.5 in magnitude or any earthquake causing “weak” shaking in the L.A. area, regardless of its epicenter location. (Previously, the app sent alerts for local earthquakes above a 5.0, or any earthquake causing “light” shaking in the L.A. area.)
Some are concerned that the likely increase in alerts could lead to complacency, meaning Angelenos won’t drop, cover and hold when an alert for a major earthquake actually comes. Others say more information is better than less information when it comes to earthquakes.
Larry speaks with a USGS official about the decision to lower the alert threshold, how the app is supposed to work, and more.
Robert de Groot, staff scientist and coordinator for communication, education and outreach for the ShakeAlert Earthquake Early Warning Project at the U.S. Geological Survey Earthquake Science Center in Pasadena