As expected, today California governor Gavin Newsom announced the launch of a statewide Earthquake Early Warning System.
Based on reports from sensors embedded in the ground across the state, it can detect tremors and deliver warnings to mobile phones using the Wireless Emergency Alert system or the MyShake app (Android, iOS).
This system is launching on the 30th anniversary of the Loma Prieta quake in 1989, and if this system had existed then, people attending the World Series game at Candlestick couldve been notified up to 15 seconds before the quakes tremors actually reached them.
This system doesnt predict earthquakes, and after quakes early this year failed to produce a notification on phones in Los Angeles, the threshold for a warning has been lowered to at least a magnitude 4.5 and Modified Mercalli Intensity (MMI) of 3, which is similar to a truck driving by outside your house.