喜馬拉雅山還會“長高”嗎？
[ 2006-10-20 14:20 ]
|
 |
|
A picture of Mount
Qomolangma. | Will the
Himalaya Mountains, home to the world's highest peaks, continue to push up
into the sky in future? Some Chinese scientists say no.
The Himalayas may have reached their highest altitude and in the
centuries to come may even shrink a little, said Bian Qiantao, a
researcher with the Institute of Geology and Geophysics of the Chinese
Academy of Sciences.
Located on the southern rim of the Qinghai-Tibet Plateau, the Himalaya
Mountains form an arc protruding southward. The main part of the range
lies in China. "Himalaya" means "abode of snow" in Tibetan. The average
height of these mountains is more than 6,000 metres.
Scientists believe that 65 million years ago, the
Indian Plate moving north collided with the Eurasian Plate
, and the upheaval saw the emergence
of the Qinghai-Tibet Plateau as well as the Himalayas.
"Friction between the tectonic plates continues to this day, gradually
pushing the Himalayas upward," said Bian.
"But at the same time, a horizontal pulling power inside the lower
continental crust and mantle of the earth counteracts this upward
movement," said Bian.
According to measurements made by scientists in 2005, the altitude of
Mount Qomolangma is 8844.43 metres, 3.70 metres lower than the figure
obtained in 1975.
The result suggests that the Himalayas and the Qinghai-Tibet Plateau
will not continue to move up indefinitely. After growing to a certain
height, the effect of gravity and collision-generated extrusion will make
them grow wider, but not higher, Bian said.
點擊進入往期回顧
(China
Daily)
|
擁有世界最高峰的喜馬拉雅山還將繼續“長高”嗎？我國一些科學家認為“不會”。
中科院地質與地球物理研究院的研究員邊千韜說，喜馬拉雅山已基本達到最高點，在未來幾個世紀內，甚至可能會有所下降。
喜馬拉雅山位于青藏高原南側，呈向南突出的弧形，山脈的主要部分位于中國境內。“喜馬拉雅”在藏語中是“冰雪之鄉”的意思。喜馬拉雅山的平均高度在6000米以上。
科學界普遍認為，青藏高原和喜馬拉雅山是6500萬年前向北漂移的印度板塊與歐亞板塊相撞而形成的。
邊教授說：“這兩個板塊之間的摩擦仍在繼續，在這種力量的作用下，喜馬拉雅山一直在慢慢升高。”
“但同時，從下地殼一直到地幔上部在產生一種東西拉張的力量，這種拉力對喜馬拉雅山的繼續升高起到了阻礙作用。”
2005年，科學家測出珠穆朗瑪峰的海拔為8844.43米，比1975年低3.7米。
測量結果表明，喜馬拉雅山和青藏高原不會無限升高。邊教授說，喜馬拉雅山達到一定高度后，在重力和由板塊碰撞產生的擠壓力的作用下，山脈會向外擴展，而不會持續增高。
(英語點津姍姍編輯)
|
|
|
|
Vocabulary:
Eurasian
Plate :歐亞板塊
|
|
|
|
|
|
