You may ask, how does earthquake early warning function?
Earthquake early warning systems do not predict earthquakes. Instead, they consist of a network of seismometers (The California Integrated Seismic Network in the case of the state of California), that detect the fast moving P-waves of an earthquake when it occurs. The data from the P-waves are used to determine the magnitude as well as location of the epicenter, and warnings are quickly sent out to those who will be affected.
California State Senator Alex Padilla (who introduced the bill) stated in a press release on the 12th:
"We live in earthquake country. When it comes to earthquakes in California, it is not a matter of if, but when. A fully developed earthquake warning system will provide Californians critical seconds to take cover, assist love ones, or pull over safely to the side of the road. It could allow time to stop a train and power down critical infrastructure. Most importantly it will save lives."
Currently a prototype system known as Shakealert is in place, however it is not yet ready for public use.
A video of the earthquake early warning system in Japan during the 2011 Tohoku Earthquake is shown.
For more videos on earthquake early warning visit my up-to-date post: Videos of Earthquake Early Warning