QUAKE ALERT HAS A LONG WAY TO GO SOME EARLY WARNING SYSTEMS DEVELOPED RESEARCH UNDER WAY.

Byline: ALEX DOBUZINSKIS

Staff Writer

The 1994 Northridge Earthquake struck without warning, killing dozens as it shook buildings for miles and downed freeways in the Newhall Pass.

Nothing could be done to alert residents as the quake devastated the San Fernando and Santa Clarita valleys.

But someday, experts say, an earthquake warning could go out to Southern California residents under the right conditions.

If a quake is centered in the desert, electrical signals could warn of its approach seconds before deadly waves of ground movement roll into populated areas.

Earthquake early warning systems have been developed with varying effectiveness in Mexico City and parts of Japan.

In California, university researchers are doing preliminary studies on a warning system -- but their work has barely gotten to the drawing board.

A California warning system has been talked about for more than a century, but years of work remain. And all the effort would be for a system that would give limited warning -- or none at all, depending on where a quake starts.

"We're talking about a few seconds to a few tens of seconds," said Jim Goltz, earthquake and tsunami program manager for the governor's Office of Emergency Services.

"If you get a few seconds of advance warning, I think that you could reasonably expect schoolchildren to take self-protective measures," he said. "I think you could alert people to move away from hazardous materials or hazardous situations."

In 2005, a workshop on earthquake early warning was held at the California Institute of Technology and drew dozens of researchers. But the idea had been talked about well before then.

In 1868, a doctor named J.D. Cooper wrote an editorial in the San Francisco Daily Evening Bulletin calling for the creation of an earthquake early warning system using electric wires and a bell hung from a tall building in the center of the city.

Mexico City has been devastated by earthquakes, most notably a 1985 temblor that killed thousands. In the years after that quake, a system to warn residents of an approaching earthquake was developed. In 1995, a quake was detected, and residents were warned by radio broadcast. But experts say Mexico City's system benefits from a geographical quirk Southern California doesn't have.

Most earthquakes that hit Mexico City come off the West Coast, hundreds of miles away, and instruments can detect them before they hit the city, experts said. In Southern California, fault lines cross urban and rural areas alike, making early detection more difficult.

In the 1994 Northridge Earthquake, Santa Clarita was about a dozen miles from the epicenter, but it was right in the path of the quake's strongest thrusts, said Adele Macpherson, emergency manager and community services superintendent for the city. "I had to hold on to the side of the bed to keep from getting thrown in the air," she said, recalling the early morning shaker.

She remembers a sky full of stars, an eerie result of the city's fog of electrical lights blacking out. She also remembers mobile homes shaken off their moorings and firefighters scrambling to extinguish blazes caused by ruptured gas lines.

"Sporadic fires and explosions all around, gas and electric connectors, and the earth just didn't stay still," Macpherson said.

If a system could warn of a quake before it reached a city, the damage would still be extensive. But elevators could be triggered to let passengers off at the next floor, computers could automatically turn off to save data, and telephone traffic could be rerouted to help residents communicate after a quake, experts say.

Preliminary studies on earthquake early warning are under way at the University of Southern California, the University of California at Berkeley, and California Institute of Technology, Goltz said.

"All three of these efforts are basically looking at algorithms," he said. "Looking at ways in which an evolving seismic sequence can be translated, if you will, into some type of an advance warning for communities that are somewhat distant from the source of the earthquake."

In an ideal situation, an earthquake originating on the San Andreas fault around the Salton Sea could be detected before it rumbled through the Los Angeles Basin, Goltz said.

In Japan, an earthquake early warning system has already worked for detecting quakes and warning of their approach, according to Shigeki Horiuchi, an expert on the system who works for the National Research Institute for Earth Science and Disaster Prevention.

"I think the construction of (an earthquake early warning system) in Southern California (needs a) huge number of stations," Horiuchi said by e-mail. "Good EEW needs stations with space density of 5kilometers to 10kilometers because most of (the) large earthquakes in California occur beneath land area close to big cities."

Experts say Japan has more earthquake-detecting devices than Southern California, which gives it a head start. The Japanese hope to have a system in place to issue mass warnings in September, Horiuchi said.

In Southern California, researchers say they're a long way from replicating what Japan has done. Building a complete system would require a huge public outreach campaign.

"The costs are somewhat unknown," Goltz said. "And it depends upon whether or not potential users are willing to make certain kinds of changes or investments."

Researchers say funding for a warning system is always talked about after a major quake but soon forgotten.

Ken Hudnut, a geophysicist with the U.S. Geological Survey, has looked into the possibility of using global positioning technology to warn of approaching earthquakes. But he said a complete system is still a long way off.

"There hasn't been enough money to do anything beyond very simple research and development," he said.