Savanah Purnell, 4, right, hugs her classmate Madison Messier, 4, as they participate on the Southern California earthquake drill at the Altadena Christian Children's Center in Altadena, Calif. on Thursday, Nov. 13, 2008. (AP Photo/Damian Dovarganes)
Upgrades to hundreds of seismic monitors around the state are expected to buy time -- about five seconds -- before the shaking.
The LA Times reported that 90 percent of Southern California's monitors are already undergoing the major upgrade. Officials have started a pilot program that takes advantage of the new devices by delivering early warnings to first responders and utlities.
Eventually, the system could be used to warn the public that the shaking is about to begin.
Research about the system was presented this week at a conference of seismologists in San Francisco.
"I'm confident that if we had the information, we could use it to our advantage," Tom Jordan, director of the Southern California Earthquake Center, told the LA Times. "The main issue here is to have our communities be resilient to earthquake damage."
Scientists said the warning would be especially effective when quakes originate outside urban areas, such as along the San Andreas fault.
Such systems are already used in parts of Mexico and Japan, which has a system that can provide a warning 30 seconds or more before shaking starts. Messages are delivered on TV and radio stations, via texts, and through speaker systems in public areas.
As the Times reported, attempts to provide early warnings date to the late 1860s:
The pursuit of early warning in California dates to 1868, when a simple system was proposed after a quake along the Hayward fault east of San Francisco, according to a recent paper in the journal Seismological Research Letters. The rudimentary system would have used telegraph cables to ring a distinctive bell warning people of impending shaking.
Caltech and the U.S. Geological Survery are conducting the upgrade. A full, state-wide early warning system would cost about $80 million to $100 million, according to the Times.