California Launches Earthquake Early Warning System

What is particularly good here is that the means to test this will be obvious.   I get USGS reports on earthquakes via an App, can filter them to mag 4.5 and higher, minutes after they occur.  So comparison to predictions should be straightforward.  Look forward to ongoing analysis.

California Launches Earthquake Early Warning System
Calls it the best in the world    in Reuters  By Dan Whitcomb 

California has launched the first statewide earthquake warning system in the U.S., aimed at detecting seismic waves and notifying residents via a mobile phone app up to 20 seconds before tremors hit. The California Earthquake Early Warning System taps hundreds of sensors to detect P-waves, which travel through the interior of the Earth, and arrive prior to surface waves and at a higher frequency during a temblor. University of California, Berkeley seismologists and engineers designed the MyShake phone app, which will initially warn users of local quakes with a magnitude of 4.5 or higher. Alerts are based on the ShakeAlert computer program operated by the U.S. Geological Survey, which analyzes data from seismic networks across the state, estimates the preliminary magnitudes of tremors, and calculates which areas will feel them.  ... "

Here is more about the early warning mobile App. I have it installed.