Just one year ago, China’s deadly earthquake struck with abnormal power, leaving close to 90,000 dead or missing. Could China’s unrestrained dam building have triggered this “sleeping dragon,” we wondered. Within days we had reached our colleagues in China and confirmed that the possibility was real and, as many scientists are now saying, likely.
The main suspect is the Zipingpu dam, which Chinese environmentalists had bravely tried to stop from being built. Zipingpu, completed in 2004, was built just a few miles from the epicenter of last year’s deadly quake, its reservoir straddling the major Beichuan fault line. In May 2008, after it was rapidly drawn down in preparation for the rainy season, the deadly quake struck.
Within days of the quake, Fan Xiao, China’s chief engineer of the Regional Geology Investigation Team of the Sichuan Geology and Mineral Bureau, called on Chinese officials to investigate the seismic readings to determine whether the Zipingpu dam had induced this disaster.
Chinese electric utility officials, whose frenzied dam building schemes were suddenly threatened by the possibility that this “natural disaster” was actually a “man-made disaster” and that public outrage would stop their plans, dismissed Fan Xiao’s warnings.
Then, in December 2008, Columbia University’s geophysical hazards scientist Christian Klose, who had investigated the earthquake, presented his findings at an American Geophysical Union meeting. He hypothesized that the added water from the reservoir changed the stresses on the Beichuan fault, rupturing it with an effect 25 times that of a year’s worth of natural stress loading from tectonic motions.
Soon after, Chinese geophysical scientists published their findings in the Chinese scientific journal, Seismology and Geology, saying “the impoundment of Zipingpu Reservoir clearly affected the local seismicity and it is worthwhile to further study if the effect played a role in triggering the … earthquake….The issue shouldn’t be avoided.”
Some 90 cases of dam-induced quakes around the world have been observed since the 1930s. Typically, this seismicity occurs immediately after the reservoir is filled or after it is drawn down: dam reservoirs are now thought to affect the timing, the location, and the severity of earthquakes.
Zipingpu may be the most dramatic and the most deadly dam-induced earthquake ever documented.
Though Chinese and foreign geologists are calling for a full-scale scientific assessment of the readings leading up to the Sichuan earthquake, Chinese authorities are not releasing the data. Until more is known, the risk is great that millions of Chinese citizens could be similarly threatened by the dozens of dams planned and under construction in this highly seismically active area of China.
Over the last decade, Probe International has focused on dangers from dam building, working to ensure the free flow of scientific analysis. To enable the Chinese citizenry to have access to documents affecting their health and safety, and to ensure Western scientists can add their knowledge to that of Chinese experts, we translate and publish analyses in both English and Chinese. Probe’s news coverage on our bilingual websites has been crucial to a full airing of this most important public safety issue.
If you are able to help us, we will continue to support the brave and conscientious Chinese scientists, citizens, and environmentalists who want the seismic data investigated and future dams scrutinized. This may be the single most important way to protect the lives of Chinese citizens from a repeat of the dreadful May 12, 2008 catastrophe.
Categories: Campaign Letters