Quake Expert’s Message Is the Same, but He Uses a Lot Less Magnitude : Seismology: After the Landers temblor, his warnings about the Big One shook up a lot of people. He is still driving home his point: Be prepared.

In the days after the strong Landers earthquake, Allan G. Lindh’s warnings of a possibly imminent Big One were so provocative and became so highly publicized that his superiors back East advised him to tone down.

As a result, these days Lindh, the top seismologist in California for the U.S. Geological Survey, is almost contrite.

“I’m sorry if I scared the people of L.A. unnecessarily,” said Lindh in an interview in his cluttered office at the Geological Survey’s western regional headquarters.

“I don’t want to scare them now. I want them to grow up enough to do the things that should be done. A large fraction of the people who die in the next big earthquake in L.A. will die unnecessarily, and they will have no one to blame but themselves.”

For the 49-year-old Lindh, a man with a flowing beard and striking eyes, earthquake preparedness is the center of his life.

“His driving force is to get the message through to the public that we can survive earthquakes,” said Geological Survey spokeswoman Pat Jorgenson. “His whole message is preparedness. He is absolutely dedicated to the fact that taxpayers pay the bills and he works for them.”

But, she added, despite being assigned to coordinate the efforts of 250 quake scientists working in Menlo Park, Lindh is “absolutely the antithesis to the desk-bound bureaucrat. I think he’d be the first one to say: ‘Hey, I’m not the most popular man on campus. I’m not a popular branch chief. I’m not an administrator.’ ”

The day after the magnitude 7.5 Landers earthquake, the state’s strongest in 40 years, Lindh flew to Southern California and joined a lengthy news briefing at Caltech. It was his voice that sounded more alarming than anyone else’s about the prospects of a big earthquake, and help set off jitters about the possible Big One.

“There is evidence we’re near the jumping-off place for a big one on (the San Andreas),” he said then.

In ensuing days, Lindh called the Landers earthquake “like a final warning” and advised Southern Californians to “act as if the damn thing will happen tomorrow.”

Lindh is unhappy about the reporting of such statements, because, he says, his briefings and interviews usually lasted more than an hour and only one or two provocative sentences were quoted in the newspapers.

“It’s absolutely a mistake to say that I’ve ever thought a big one was imminent,” he told The Times in a recent interview.

Quakes cannot be predicted well enough to be judged as imminent, he said. The likelihood of a big quake can be discussed only as a probability, Lindh said.

“I have been writing for 15 years of the necessity of a probabilistic approach to earthquake prediction--which emphasizes how much we don’t know,” Lindh said. “And neither I nor anyone I know in the whole wide world has any basis for shorter, intermediate earthquake predictions that are not of a probabilistic sort.”

So, he said, although there is a consensus in the scientific community that the Landers earthquake sequence has increased the risk of the Big One along the San Andreas Fault in Southern California, that risk may have gone up only from about 2% a year to 4% a year. Even that kind of rise “would be sort of a big deal to a seismologist,” he said.

Whenever one talks in numbers there is always fear that he will be misinterpreted, Lindh said, although now he wishes he had given the 4% more mention than the “damn thing happening tomorrow.”

In any case, he added, there is a misperception among many people that the Big One, when it does come, will be a “civilization-threatening catastrophe.”

“It could have been. The Minoan civilization was probably lost to a volcanic eruption. But we are not vulnerable, thanks to the engineers and the building codes we have.”

As for preparedness steps for individuals, Lindh is high on a few specifics.

He is adamant that all houses and stationary house trailers should be bolted to their foundations. Otherwise, “if the house shifts six inches or a foot, and they have a rigid pipe gas line, it stands a good chance of being ruptured. They have a chance of an explosion that will kill the kids, and they have a real chance of a fire.”

Another thing he advocates is placing plywood boards in the attic around brick chimneys. This will prevent chimney bricks from cascading into the living room, threatening people who may be there when a temblor strikes. Lindh notes that falling chimney bricks were responsible for the lone fatality in the Landers quake.

Lindh earned his Ph.D. at Stanford University at an older age than most doctoral graduates. His college years were delayed, he says, because he quit Yale University and went to Canada in protest against U.S. policy in Cuba and Vietnam. “I was a ‘60s dropout with about half my generation,” he said.

Later, he became interested in geology while driving a truck in a British Columbia oil field. He noticed that the only man on the scene able to keep dry and warm was the resident geologist.

In his nine years with the Geological Survey, Lindh has been closely associated with the National Earthquake Hazard Reduction Program, working on quake preparedness, and has also been involved with earthquake prediction studies.

It was Lindh who started and for a while directed the Parkfield Prediction Experiment. In 1985, a scientific task force declared that there was a 95% chance of a magnitude 6 earthquake occurring near the Central California town of Parkfield, on a segment of the San Andreas Fault, by 1993.

With less than five months remaining in the window, no such quake has occurred, and Lindh remarks with a laugh that the chance of the quake fulfilling the scientific prophecy has grown slim. “This is now time for prayer,” he joked.

Lindh was also on a task force that in 1988 evaluated the chances of a big earthquake occurring on the southern San Andreas Fault at 60% by 2018. Just last week, the Geological Survey and the California Office of Emergency Services named a 12-member scientific review panel chaired by Keiiti Aki of USC to re-evaluate those probabilities. Lindh was not named to the new panel.

Dedicated as he is to San Andreas hazard reduction, Lindh still confesses to a high regard for the value of the fault.

“California is created by the San Andreas Fault system,” he said. “All the mountains, the coastline, the valleys. Semi-seriously, one time I tried to add up the economic benefits of the San Andreas and it came to at least $15 billion a year.”

He asserts that without the fault there would be no Sierra Nevada range, and thus an insufficient water supply for California’s agriculture and its great cities. Without the folds created by the fault, the state would not have nearly the oil and gas reserves it has. And without such faults as the San Andreas and the Newport-Inglewood, the state’s most valuable harbors would also be missing.

“How many of us would live in California if it didn’t have the beautiful mountains, valleys and coastline?” Lindh asks. “We wouldn’t be able to afford to live here. It would be a desert. . . . We’re here because of the world the San Andreas has created, and it’s a great world.”