The devastating earthquake that killed 80,000 people in China’s Sichuan Province last May may have been triggered by a recently built hydropower dam that lies only three miles from the quake’s epicenter, some researchers are arguing. The several hundred million tons of water piled behind the Zipingpu Dam put just the wrong stresses on the adjacent Beichuan fault, [says] geophysical hazards researcher Christian Klose [Science, subscription required].
The 7.9 magnitude earthquake left more than five million people homeless. It remains a raw and emotional topic for most Chinese, and the government has been quick to quash any suggestion that Zipingpu may have been responsible for the catastrophe. Researchers have been denied access to seismological and geological data to examine the earthquake further [Telegraph]. The few researchers who have investigated the subject are now urging restraint in government plans to build more dams, but they say their advice is unlikely to be heeded.
The first evidence regarding the Zipingpu dam’s possible contribution to stresses along the fault have been presented at the American Geophysical Union meeting and the Chinese journal Geology and Seismology, according to a report in Science [subscription required], and now other researchers and officials are beginning to speak up. 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” [Telegraph].
Fan says that researchers haven’t definitively proved a causative link between the dam’s filling and the earthquake, but he believes the evidence is strong enough to merit careful study before more dams are built. “We should readjust our existing plans and take a more cautious attitude when planning projects,” he says. “But I am pessimistic that many of these large-scale constructions will be canceled, because of the strong economic interests that benefit hydro-power developers and local governments” [Science, subscription required].
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Image: flickr / kenner116
February 2nd, 2009 at 7:07 pm
Absurd. Not only is the dam three miles away, the epicenter was 12 miles deep below the surface, in solid granite. That makes the Zipingpu dam the equivalent of a mud puddle. If that splash of water triggered an earthquake in that much rock, then the quake was going to happen any way.
February 4th, 2009 at 9:59 am
The possibility of such an unintended (and devastating) consequence needs further investigation. But with the present climate of censorship in China, it’ll be more potential dirt swept under the rug of cover-up.
February 6th, 2009 at 11:56 am
Jon– scientists do say that if the dam was a trigger, it would have simply brought on a quake that would have happened eventually anyway. But I wouldn’t be so quick to dismiss the idea all together. The dam was about one-third of a mile from the fault line.
The New York Times just came out with a good article about this. It mentions “a 1967 earthquake triggered by the Koyna Dam in a remote area of India, with a magnitude of about 6.5 and a death toll of about 180 people.”
February 6th, 2009 at 8:31 pm
In fact, the distance between the reservoir and the fault line is very interesting.
Anyone who has a little knowledge about levers knows that one can use a little weight on a long arm to lift a large load on a short arm. If the dam happens to be sitting on the long side of a focus, it can really tilt a big slab of rocks on the short end of the focus. The water behind the Three-Gorge dam may cause an earthquake hundreds of miles from it, depending on where the focus is.
March 25th, 2009 at 12:12 pm
i think the chinese governement is dealing with this the same way as with the land mines. He figures eventualy all the earthquakes will happen, then it’s over. with the landmines, he figures eentualy random citizens would step on them all over time. Pethetic
April 28th, 2009 at 9:45 am
I strongl believe that the chineese goverment is dealing with the land mines efficantly. The citizens who step on them are just stupid.
July 10th, 2009 at 8:11 pm
Could all that water, under pressure, lubricate the fault and trigger a release?