If you live near LA, here’s an app you must add to your phone or iPad

Los Angeles now has an earthquake-alert app to warn residents before the Big One hits. Mayor Eric Garcetti unveiled the app, called ShakeAlertLA, which sends notifications to let users know if a quake of 5.0 magnitude or greater has started, buying anywhere from a few seconds to tens of seconds before heavy shaking starts. The app does not predict earthquakes before they happen, but detects them early; the technology works by detecting P-wave energy — the first energy to emanate from an earthquake — allowing the app to detect where the earthquake is coming from and how strong it will be. Meanwhile, Southern California’s KPCC public radio just launched a podcast called “The Big One: Your Survival Guide.”