As Californians remember the Loma Prieta earthquake on this 30th anniversary of the day the 6.9 magnitude shaker left 63 people dead, the state is launching the nation's first statewide Earthquake Early Warning System.
Officials say the California Earthquake Early Warning System combines a new smartphone app with a more traditional alert and warning delivery methods like wireless emergency alerts. The system monitors earthquake motion sensors which have been placed all over the state. Those sensors are said to be so sensitive that they can detect earthquake vibrations before you can feel them, and the system is fully automated. It's supposed to give you enough notification of an earthquake that you have time to "drop, cover. and hold on" to help prevent injury, as experts recommend.
"Today’s announcement reflects our commitment at Cal OES and across the Administration to use the best available science and technology for earthquake detection and warning. These early notifications greatly increase our ability to prevent injuries and even save lives," said Mark Ghilarducci, Director of the Governor's Office of Emergency Services.
State officials still encourage families to have a plan in place for earthquakes and other emergencies. "We know the Big One might be around the corner. I encourage every Californian to download this app and ensure your family is earthquake ready," said Governor Gavin Newsom during a new conference in the Bay Area on Thursday.
The amount of advance notice you get is going to depend on how far you are from the epicenter of an earthquake. OES says during the Loma Prieta Earthquake in 1989, which had an epicenter near Santa Cruz, for example, those attending the World Series game at Candlestick Park would have received up to 15 seconds of warning, while people living in Marin County, would have had advance notice of as much as 17 or 18 seconds. The first version of the new app is expected push out alerts to your phone for earthquakes exceeding magnitude 4.5 where you are at the time.
Warnings delivered through the system are based on a computerized program called ShakeAlert operated by the U.S. Geological Survey (USGS) that analyzes data from seismic networks in California, calculates preliminary magnitudes, and then estimates which areas will feel shaking.
The new app was designed by University of California, Berkeley seismologists and engineers, and it's available for downloaded through iTunes or the GooglePlay stores.
California is not the first to have an early warning system like this one. Earthquake-prone countries like Mexico and Japan have had similar systems, with alerts typically delivered through cellphones or public address systems for a long time. However, California will be the first state in the nation to offer earthquake early warning.