WEI Fangqiang knows what it's like when a mountain crumbles: The Longmenshan, or Dragon's Gate Mountains, are prone to landslides. But when the physical geographer and seven colleagues with the Chinese Academy of Sciences' Institute of Mountain Hazards and Environment (IMHE) in Chengdu trekked into the area devastated by the Sichuan earthquake, they were stunned. It looked as though the hills had been blown apart. Landslides had flattened several-story buildings in the town of Beichuan and annihilated villages that clung to the steep slopes.
At 2:28 p.m. local time on 12 May, the Sichuan earthquake struck with a magnitude of 7.9. It "was not a total surprise to geophysicists," says Mian Liu, a geophysicist at the University of Missouri, Columbia. It occurred on a well-known, active fault system, he notes, which in 1933 produced a magnitude-7.5 quake that killed about 9000 people. But the death toll of the Sichuan earthquake is horrific. As of 20 May, more than 40,000 people are known to have perished, including thousands of children.
Landslides unleashed by the rupture of a more-than-200-kilometer section of the Longmenshan fault, followed by powerful aftershocks, dammed parts of nine rivers, creating 24 new lakes. The biggest and most threatening is 3.5 kilometers upstream of Beichuan. If the debris dam were to break, the resulting flood would threaten relief workers and researchers in Beichuan. "We're worried about another catastrophe," says Wei. The IMHE researchers plan to head into the field as early as next week to sample landslide material and draw topographic maps. A future task is to advise authorities on a safe place to rebuild Beichuan city. The original site will almost surely be abandoned.
Down the road from IMHE, researchers with the Chengdu Institute of Biology (CIB) are mourning three senior staff members who died when the wall of a hostel in the mountains collapsed as they were dashing out of the door for safety. A week after the quake, 10 of their colleagues were stranded at CIB's Maoxian Mountain Ecosystem Research Station in a pine forest 220 kilometers northwest of Chengdu. The institute had a couple of dozen long-term projects in the disaster area, a biodiversity hot spot that encompasses 22 nature reserves. They'll have to write a new research plan. "The earthquake has dramatically changed the landscape," says CIB ecologist Luo Peng. One urgent task is to monitor bamboo. The plant flowers once every 70 years or so. Shortly after a powerful earthquake in the 1970s, large swaths of bamboo suddenly flowered and died, says CIB ecologist Pan Kai-Wen. How a quake might trigger flowering is a mystery, but a large-scale die-off, he says, could pose a big threat to China's endangered giant pandas.
Meanwhile, some experts argue that the Sichuan disaster should stimulate China to rethink its entire approach to earthquake research. "In recent decades, geophysicists have spent too much energy and funding on research on deep-earth structure or tectonics," says Zhou Shiyong, a geophysicist at Peking University. He argues that more attention should be devoted to earthquake prediction.
One thing that will surely come under scrutiny is China's construction standards. "More effort should be devoted to earthquake hazards analysis and management, including developing and enforcing proper building codes, especially for schools, hospitals, and other public buildings," Liu says. For thousands of victims in Sichuan, that lesson came too late. (ScienceNOW Daily News 21 May 2008)