The Next L.A. / Reinventing Our Future : Preparedness : Seismologists could wire Southern California from top to bottom with sensors and seismometers.

In preparing for an earthquake, as in the art of war, knowledge of the enemy is the key to victory.

Yet in Southern California, perhaps the most intensively studied earthquake region in the world, scientists readily acknowledge they have only the barest inkling of what’s going on beneath the grass, rock and asphalt on which the region rests.

What they do know is unsettling: The San Fernando Valley and the Los Angeles Basin balance on a cobweb of hidden thrust faults, and the surface of Southern California is crisscrossed by 42 major faults that mark the fractured boundaries between tectonic plates.

Until recently, scientists paid most attention to the faults they could see easily at the surface--such as the infamous San Andreas fault--but earthquake experts are now aware that subterranean faults can be equally dangerous, adding an ominous new dimension to the earthquake threat in the Los Angeles Basin.

In 10 seconds last month, that threat became manifest.

A single deeply buried fault ruptured between 11 and 12 miles under Northridge, slamming the Earth above in a violent uppercut. The energy it generated was enough to kill at least 57 people, injure thousands, cripple parts of the freeway system and cause an estimated $30 billion damage. The forceful shaking from the quake was two to five times what San Francisco experienced in the 1989 Loma Prieta earthquake.

Any one of the dozens of other hidden faults could rupture at any time, with just as much damage or more.

Decades of scare stories about the Big One had done much to prepare Southern California for a major earthquake, but--as the Northridge quake made instantly clear--not nearly enough.

The ability to predict an earthquake--or even provide some early warning of a major shock as it begins--could revolutionize the region’s ability to withstand a major temblor.

Scientists today can no more predict the next earthquake than they can predict the winning number on a roulette wheel.

But if they could afford enough of the new technology now becoming available, they might one day dare to try.

Seismologists and geophysicists dream of weaving all of Southern California together in an elaborate skein of thousands of motion sensors, seismographs, accelerometers and satellite links. Tied together by a high-speed satellite cellular network, the instruments could provide crucial early warning of a major earthquake and serve as the heart of an automated regional earthquake safety system.

A network of seismographs could be installed along major known faults in Southern California, such as the San Andreas fault, and tied into a wireless emergency network that would automatically be triggered by the first rumbles of a major earthquake seconds before the ground shocks could reach Los Angeles.

Seismologists and geologists say such a system could give 20 seconds’ or 30 seconds’ warning in the event of a San Andreas earthquake--long enough to automatically shut down critical utility lines, sound school alarms, send high-rise elevators to open at the nearest floor, trigger stop lights, warn trains and wave off approaching aircraft.

That elaborate sensor system would also start giving scientists the kind of continuous detailed information they need about the region’s hidden landscape of fault scarps and buried fissures.

One earthquake expert recently spoke wistfully of planting seismographs every 100 yards throughout Southern California. “Then we’d learn something,” he said.

More detailed seismic profiles would mean better pictures of the buried faults under Southern California. That will help scientists pinpoint the source of earthquakes and better understand the stresses that trigger them.

Scientists hope that once they can fathom the causes of the region’s earthquakes, they will one day be able to issue earthquake forecasts, like tornado warnings.

They are close.

Barely two months before the Northridge quake, for example, a geophysicist at the Jet Propulsion Laboratory warned in the prestigious science journal Nature that the strain building up in the Ventura Basin--60% greater than that at the San Andreas fault --could result in an earthquake of magnitude of 6.0 or greater.

Of course, no one was able to predict just when that strain would trigger a lethal temblor.

Just to develop a detailed seismic image of the entire Los Angeles Basin could cost millions of dollars. No state or federal agency has the money for seismic mapping on that scale. Major oil companies that hoard a trove of detailed seismic data on the area are reluctant to open their files to outsiders.

In the open desert, fractured faults exposed by erosion are easy to spot, but penetrating the mask of urban concrete that hides evidence in the Southland’s heavily populated centers is almost impossible. Occasionally, geologists can gather the necessary city permits to set off a blast that will generate the seismic echoes used to map new faults, but the experiments generate an avalanche of hate mail and thousands of abusive telephone calls from people afraid that the research itself will trigger the next earthquake.

In part, the effort to better understand earthquakes is hindered by regional factionalism and the federal budget crush.

Thirty-seven states have a significant earthquake problem, but the hazard still is perceived mostly as a California problem. No one has been willing to sponsor additional earthquake research utilizing Southern California’s local seismic hazards as a model for a hazard that could, in principle, just as likely strike the Midwest, New England or the Pacific Northwest.

Even in Japan, where the resources devoted to earthquake preparedness dwarf those invested in California, the survival of freeways and buildings in a major earthquake is considered as much a matter of luck as rigorous preparation.

Nonetheless, Tokyo alone spends an estimated $1 billion a year on earthquake preparations ranging from mandatory emergency drills to meticulous fire-prevention precautions.

Japan is the only country with a major earthquake-prediction program integrated into its emergency disaster-planning program. Among other things, Japan has set up an early-warning system in areas where most great quakes strike to transmit a warning as soon as the Earth begins to shake. The warning is used to safely shut down the country’s high-speed rail system before the damaging shock waves reach the rails.

The only emergency seismic warning system in Southern California--a paging system--is funded privately through Caltech because the U.S. Geological Survey (USGS) doesn’t have the money to pay for it.

Indeed, many federal geologists are frustrated by their inability to command the kinds of resources necessary to carry out important earthquake research. For $100 million - less than the cost of the spy satellites accidentally destroyed in a launch mishap at Vandenberg Air Force Base last summer - seismologists in Southern California could wire the region from top to bottom with the sensors and seismometers necessary to understand the area’s earthquake threat.

“The USGS hasn’t hired anyone in so long that the average age of survey scientists is 51 years old,” says one senior survey geologist who specializes in earthquake predictions. “We’re such a peanut outfit we couldn’t afford our own paging system.”