China's Campaign to Predict Quakes
by Li Hui and Jeff Mervis
A vast, 30-year effort to monitor the earthquakes that regularly shake China has led to unprecedented and controversial success in predicting them. What's behind this empirical approach.
...Western scientists who have recently seen some of the data amassed by the Chinese for the first time share these reservations. But they believe the information could point to some interesting lines of research. This summer, for example, a joint team of Chinese and US researchers published an analysis of resistivity signals - a measure of current flow that correlates with the amount of cracks and fluid in the Earth's crust - from the Tangshan region in the 2 to 3 years preceding the 1976 quake that point to several possible precursors (Journal of Geophysical Research, 10 June, p.13869). "These are interesting phenomena that suggest things we could measure," says co-author and seismologists Leonardo Seeber at Columbia University's Lamont-Doherty Earth observatory, about a finding of lower resistivity and a descending water table in the period before the quake. "The next step is to understand the process and see if it can be generalized."
Apart from the value of the data sets, the authors see the collaboration as a step toward improved relations. "This is the first time we've been able to get our hands on the actual data," says co-author and geophysicist Chris Marone of the Massachusetts Institute of Technology. Adds Seeber, "The Chinese have proposed these results before, but the community had looked at them with skepticism."
To some Western scientists, the program also illustrates an interesting cultural difference in the way science pursued. "The Chinese are more comfortable than Western scientists with conflicting and contradictory evidence," says Louise Comfort, a specialist in seismic policy at the University of Pittsburgh who drafted the proposal for the new UN program. "When they face this problem, they just broaden the scope of the inquiry and collect more data."
And collecting more data is exactly what the Chinese will continue to do. "We'll try to make accurate predictions while going on with research, and we'll learn from both successes and failures," says Ge of SSB. Even geophysicist Chen believes that the government's overenthusiasm for predictions is outweighed by the importance of the challenge and China's success to date. "If we had not been able to predict a certain type of quake," he says, "we would have given up the prediction effort altogether. But now we are right in the middle, and we are left with no alternative but to go ahead."
The Lessons of Qinglong County
(Inset in article)
When the earthquake hit, Qinglong County was ready. Days before a magnitude 7.8 leveled the neighboring big city of Tangshan in northeastern China, county officials had decided to act on anomalous data collected by the State Seismological Bureau (SSB) that pointed to a major earthquake in the region during the latter half of July 1976. They set up a 24-hour command post, beefed up monitoring, strengthened safety measures at schools and other public places, and flooded the community with information about what to do before, during and after an earthquake. Many villages ordered residents out of their home and into makeshift sheds or fields.
The initiative - no official prediction was issued - paid off handsomely when the earthquake struck at 3.42 a.m. on 28 July. Only one person from Qinglong County died from the quake, while more than 240,000 people were killed in Tangshan and the surrounding area. Its population of 470,000 survived unscathed despite the collapse of 7000 buildings and damage to 180,000 more structures. It was a " fortunate leak and misuse…of inside information," says Ge Zhizhou, the SSB,s deputy director.
The actions of these local officials, which have only recently become known to Western authorities, have galvanized a new United Nations program to mitigate the destruction caused by natural disasters in the developing world. The goal is to give local. Officials’ greater access to whatever scientific information exists about potential earthquakes in their countries, as well as to strengthen their ability to act on such warnings to save lives and property. In December (actually held 20-28 January 1997), representatives from a dozen or so countries will meet in Beijing to discus a range of joint activities. An anonymous donor has provided $150,000 in seed money for an effort that UN officials project could extend for 20 years and cost a total of $100 million.
"When they tell you a hurricane is coming, you prepare. But earthquakes are different - they are the disaster we have the most trouble managing," says Jeanne-Marie Col, who runs the UN Global Programme for the Integration of Public Administration and the Science of Disasters. "So when I found out what they were doing in China, I realized they could be predictable."
Although preparation is the key to successful hazard mitigation, it was a chance meeting at UN headquarters between Col and geophysicist Jean Chu that launched the UN program. Col and consultant Louise Comfort of the University of Pittsburgh were plotting a follow-up to a 1993 meeting in Jakarta, Indonesia, on disaster management. Col recalls, when "..one day Jean Chu showed up and fulfilled my dreams". Chu, who now works in Beijing as both a researcher for the Institute of Geology of the Chinese Academy of Sciences and a UN consultant, had come to New York with the idea of raising public awareness of natural disasters Reduction. It was an ideal match. "I was looking for a forum," says Chu. “I had an idea that I wanted to connect to a specific project”, says Col.
The UN program hopes to foster local and national monitoring efforts in such earthquake-prone regions as Turkey, Indonesia and the Philippines, as well as sharing what China has learned about emergency preparation and management. The hope is that, armed with such information, public officials around the world will behave prudently, as did those in Qinglong County.