Some scientists are claiming that the Sichuan Earthquake, which killed over 70,000 people, might have been caused by a 150m-high dam constructed just 170m from the fault line.
The Zipingpu dam, 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.
The reason scientists want to look into it further is because an earthquake of that magnitude is incredibly unusual for the area. In fact, according to Christian Klose of Columbia University’s Lamong-Doherty Earth Observatory, there had been no “major seismic activity” on the fault line for millions of years.
Fan Xiao, the chief engineer of the Sichuan Geology and Mineral Bureau, said that there have been many cases in which water reservoirs have triggered plate shifts. The government had been warned about the danger of building so many massive projects so close to a fault line but had not heeded them, Fan said.
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.
The Hoover Dam is one of the most famous examples of water reservoirs allegedly causing earthquakes. The area around Lake Mead experienced several shakes (though nothing above a magnitude of 5) as the dam was filled. [Telegraph]