POSTCARDS from China : Science Marches On

Scientist Li Xuanhu, a thoughtful man drinking green tea from a jam jar, has your safety at heart--and progress to report.

“Our goal is to mitigate disaster. Some scientists say it is impossible to predict earthquakes. We think it can be done. I am not an optimist, not a pessimist. But I am confident we will slowly improve,” Li said.

Not far from the tectonically fragile heart of Beijing, the ministry-level State Seismological Bureau is heir to a long tradition. China’s first seismic reporting instrument, in which a ceramic dragon spat an iron ball into the mouth of a toad to signal a quake’s direction, dates to 132 BC.

I visited the bureau while living in China more than a decade ago. What I discovered was that it was one of only a handful of Chinese institutions to endure the tumultuous Cultural Revolution without major tumult. None since, either, I discovered this time around. “That’s why we’re so advanced today,” said He Yongnian, deputy director general.

Today, He said, China boasts the most ambitious earthquake research in the world: 11,000 staff members, 727 seismic reporting stations and 860 precursor stations in which sharp-eyed farmers help monitor everything from water table levels to animal behavior.

Li and about 1,000 colleagues labor to crack the toughest nut: imminent prediction--warnings that a region faces a quake in the immediate future.

“For intermediate predictions, that an earthquake will come in one or two years, we are getting better,” said Li. “Ten or 12 years ago we were right perhaps 15% of the time. Now about 30% of our intermediate predictions are right.” Short-term predictions of quakes a month or two ahead are chancier--no better than 10% accurate, said Li.

Imminent prediction is mostly the stuff of dreams. Yet. . . .

On Sept. 15, 1990, on the eve of the 11th Asian Games in Beijing, China’s earthquake scientists sent a secret advisory to the government predicting an imminent Level 4 temblor in the northwest suburbs of the capital. It would be felt but cause no damage, they predicted.

The 4.1 magnitude shake was felt on Sept. 22. It caused no damage, said Li, sipping his tea, dreaming on.