California’s new quake-alert app can give you vital seconds to take action

A couple of powerful earthquakes in Southern California in July came just a few months before this week’s 30th anniversary of the catastrophic San Francisco Bay tremor that killed more than 60 people. The two quakes were a sobering reminder of scientists’ predictions of another major tremor hitting the region within the next 30 years.

With that in mind, a new early-warning app launched this week by California’s Office of Emergency Services (Cal OES) couldn’t come soon enough.

Called MyShake, the iOS and Android app is designed to send out an alert moments before the shaking starts, giving you vital seconds to take potentially life-saving action.

Developed at the University of California, Berkeley, MyShake is the nation’s first statewide earthquake early-warning system, and will run alongside the existing, though slightly slower, Wireless Emergency Alert system.

The app relies on data gathered in real time from hundreds of ground motion sensors located throughout California. The sensors detect the so-called primary waves that occur at the start of a quake. These travel out from the epicenter at great speed, and are followed a short time later by stronger, more powerful secondary waves that cause all the damage. Humans can’t feel these primary waves, but the alert system can send a warning when it detects them, giving people vital seconds to act.

“The amount of advance notice received will depend on how far you are from the epicenter of the earthquake,” Cal OES said in a release announcing the app. “For example, during the Loma Prieta Earthquake in 1989 (which originated near Santa Cruz), those attending the World Series game at Candlestick Park would have received approximately 15 seconds of advance notice, and those farther north in Marin County, up to 17 or 18 seconds of advance notice.” In a best-case scenario, the app could provide a warning up to 60 seconds before the shaking starts.

MyShake will send out alerts for earthquakes exceeding magnitude 4.5, though only to people in places within a certain distance of the epicenter that the system calculates will experience a certain level of shaking. This method of focusing the alerts is designed to avoid causing unnecessary disruption — and alarm — for those a long way from the epicenter who are unlikely to feel anything during the quake.

Japan, one of the most quake-prone countries in the world, has had a similar system in place for years, though it has been known to mess up on occasion.

MyShake is one of those apps you hope you’ll never have to use, but if you live in California, or are paying the state a visit, downloading it to your phone is a no-brainer.