(April 24, 2013) In regions noted for geological instability, engineering projects built along fault lines are not only vulnerable, but may, in part, be to blame for earthquakes.
New Scientist.com reports Shemin Ge, and her colleagues at the University of Colorado, have suggested that a deadly 2008 earthquake in Sichuan province — the same region where Saturday’s magnitude-7 earthquake occurred — may have been partially triggered by a giant dam and its reservoir, completed several years earlier (the impoundment of new reservoirs is another threat factor identified in this report). Mian Liu, of the University of Missouri, told New Scientist the 2008 magnitude-8 earthquake had increased the risk of another large one within the next 50 years, and that damage sustained by Sichuan’s dams and reservoirs by the most recent disaster is of immediate concern. The area is now at risk, said Mr. Liu, who fears the two quakes may have increased stress further south along the Anninghe fault line.
By Sara Reardon for New Scientist.com, published April 23, 2013
The magnitude 6.6 earthquake that shook China’s Sichuan province on 20 April, killing over 180 people, was small compared to the magnitude 7.9 quake that struck the region in May 2008, claiming some 69,000 lives. But it provided a sobering reminder that many of China’s engineering projects are vulnerable because they sit along fault lines – and raises questions about whether they could, in part, be to blame. In unstable regions like Sichuan, it is critical to look at how building reservoirs, for example, might affect the local seismology, says Shemin Ge of the University of Colorado in Boulder. Ge and her colleagues have suggested that the 2008 quake may have been partially triggered by the creation a few years earlier of the giant Zipingpu Reservoir 20 kilometres from what would be the epicentre. The reservoir would have ratcheted up the pressure on the rocks beneath.
This story continues at the publisher’s website here.
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Fan Xiao: Did the Zipingpu Dam trigger China’s 2008 earthquake? — the scientific case