Beijing: Chinese scientists claimed to
have identified a landform left by glacial erosion at least
two million years ago on the Qinghai-Tibet Plateau.
The erosion, on the southeast edge of the plateau and
bordering the western provinces of Gansu and Sichuan, started
two million to three million years ago and ended about 20,000
years ago, said Shen Yongping, a researcher with the Cold and
Arid Regions Environmental and Engineering Research Institute.
Shen and his colleagues from the Lanzhou-based
institute are planning to complete the expedition before the
end of this year, according to the official Xinhua newsagency.
The landform, with an average altitude of 3,500 meters
atop the Zhagana Mountains in Diebu County of Gansu Province,
was first discovered by filmmakers from a cultural promotion
company in Lanzhou in 2007.
Shen said he had visited the site last year and saw
U-shaped valleys, steep ridges and enlarged hollows. "These
are typical landscape features formed by glacial erosion."
During the expedition, Shen and his colleagues would
further study its geological structure and environmental
evolution.
He said the discovery would provide important data for
research on Quaternary glaciers as well as the geography and
climate changes in western China.
Glacial erosion refers to the wearing-down and removal
of rocks and soil by a glacier.
The most extensive period of recent glacial erosion
was the Pleistocene era (1.6 million to 10,000 years ago) of
the Quaternary period, when the polar icecaps repeatedly
advanced and retreated over a period of 2 million to 3 million
years.
China has 59,406 square kilometers of glaciers, about
14.5 per cent of the world`s total. Tibet alone has 28,645
square km of glaciers.
Yet scientists say China`s glaciers have shrunk by 5.5
per cent, or 3,248 square kilometers in the past 40 years as a
result of global warming.
PTI
