How Do Earthquake Early Warning Systems Work?

California plans a system that can detect earthquake waves to warn the public.

A public earthquake warning system could be used to reduce damages and injuries on services like BART commuter trains in California.

One minute you're sitting at your desk on solid ground, the next the floor slips out from underneath you and things start to rattle off the shelves.Earthquakes seem to come out of nowhere and can cause widespread devastation.