Several scientists in China and the U.S. are claiming that the Sichuan Earthquake, which had a magnitude of 7.9 and killed at least 70,000 people, could have been caused by a 511ft-high dam just 550 yards from the fault line.
The Zipingpu dam, which is located about three miles form the epicenter of the quake, holds 315 million tonnes of water. Some geologists believed that the weight of the water, and its ability to penetrate rock, could have changed the pressure on the fault line.
From the Telegraph:
Fan Xiao, the chief engineer of the Sichuan Geology and Mineral Bureau in Chengdu, said it was “very likely” that the construction and filling of the reservoir in 2004 had led to the disaster.
“There have been many cases in which a water reservoir has triggered an earthquake,” said Mr Fan. “This earthquake was very unusual for this area.
There have been no seismic activities greater than a magnitude seven quake along this particular seismic belt before.”
By shifting a huge quantity of water into the region very suddenly, the dams could have relaxed the tension between two sides of the fault and allowed them to move apart. The effect would have been “25 times more” than a year’s worth of natural tectonic stress.
Further research is needed, the scientists admitted, but the government has been quick to deny that their massive construction projects have had any effect on the disaster. Researchers have been cut off from obtaining any more seismological and geological data.
However, many in Beijing are pushing hard to open up the area for questioning. Lei Xinglin of the China Earthquake Administration has called for a full investigation. Without one, nobody can fully confirm or deny the effects of the dams on local seismic activity.
Zipingpu is just one of nearly 400 hydroelectric dams close to the fault line. 391 of those were declared damaged by the quake.