Japan Defies Critics, Tries to Forecast ‘Big One’ : Earthquakes: Attention centers on a network of seismographs deployed southwest of Tokyo. Officials fear disaster in a wrong call.

The responsibility makes Hiroji Yamamoto squirm: One day, he may set in motion a series of events that results in the prime minister telling everyone to take cover, “The Big One” is coming.

“I’m nervous during the shift, very tense,” Yamamoto said. His eyes flitted from one computer display to another at the Central Meteorological Agency in Tokyo, the heart of Japan’s unique earthquake-prediction program.

Yamamoto’s job is to sound the first warning if he believes data streaming into the agency from monitoring equipment in the earthquake-prone Tokai region near Tokyo indicates that a temblor may be about to hit.

The only problem, say increasingly vocal critics, is that sifting through the mountains of data for signs of an imminent earthquake may be as futile as searching for the Holy Grail.

“My feeling is that if this Big One ever comes, people will have tremendous difficulty deciding when it really happens” said Seiya Uyeda, professor emeritus of the Earthquake Research Institute of Tokyo University.

“The country is so heavily populated and industrialized, a false alarm could do a lot of harm.”

Criticism has grown so strong that a panel of independent experts has been asked by the government to review the prediction program.

No other country is as prone to earthquakes as Japan, which has about 10% of the world’s seismic activity. Disastrous quakes run like a theme through its history--including the one in 1923 that killed 140,000 people in and around Tokyo.

No wonder Japan is fanatical about preparing for the next Big One.

Neighborhoods display maps of open areas to which residents can flee. They post tips on how to prepare for and to respond to an earthquake. The Japanese are forever being reminded to turn off the gas to prevent devastating fires.

Buildings are designed to be quake-resistant. An 11-story office tower in Tokyo even uses a computer and counterbalance weights to neutralize the force of a temblor.

But perhaps nothing would be better than a reliable warning. Tokyo went so far as to spend tens of thousands of dollars to determine whether catfish can predict earthquakes. The study was inconclusive.

Japan spends $53 million a year on earthquake prediction. Part of it goes for the world’s only operational, round-the-clock forecasting system, where Yamamoto works.

The system is limited to forecasting the next great earthquake in Tokai, a part of the Kanto Plain where they historically occur about every 120 years. The last was in 1854.

A network of seismographs and equipment to monitor changes in the Earth’s crust is deployed in Tokai, a heavily populated area just southwest of Tokyo. Yamamoto and others at the Tokyo headquarters evaluate the material for any unusual activity.

“We have very little actual data on the early signs of a large-scale earthquake,” acknowledged Michio Takahashi, deputy director of the Earthquake Prediction Information Division, so the agency has set standards of “extremely abnormal” activity.

Among these are three or more earthquakes an hour with an intensity of 4 or higher on the Richter scale. Takahashi said any expert would consider that to indicate a large earthquake.

Even less abnormal activity could lead to the next step: calling a meeting of six eminent seismologists to determine whether a warning should be issued.

The seismologists would be alerted by beeper, and then whisked by police to the agency, where they would gather around a large oval table on the second floor. The media would be informed of the meeting, but asked to observe a half-hour news blackout.

If the committee decided that a major earthquake is imminent, the prime minister would be notified and a statement something like this would be issued:

“Today, abnormal data were found in the earthquake observations in the Tokai district by the Meteorological Agency and we have received a report that, within two or three days, there is a danger that a large-scale earthquake may strike.”

Authorities in Tokai, which includes the city of Shizuoka with a population of about half a million, would order schools and businesses closed and curtail public transportation. Hospitals would stop taking outpatients. Residents of areas that could be endangered by huge waves or landslides would be evacuated.

An earthquake in Tokai could register 7 on the Japanese scale of seismic intensity, a “very disastrous” tremor that would destroy homes, cause landslides and create large fissures. In nearby Tokyo, the intensity would be strong enough to crack walls.

So far, Yamamoto and his colleagues have not had to summon the prediction panel, so nobody knows how smoothly the process would work. Among the concerns are that reports of the panel being convened might create panic and that the experts might issue a warning on insufficient evidence.

“Everybody should know that predicting is difficult,” Takashi said, but he quickly added that he is confident the monitoring system is comprehensive enough to pick up signs of a coming quake.

“If we can’t do it, then the whole idea of predicting earthquakes is impossible,” he said.