米国学者说了一下地震原因

NY Times 《纽约时报》

Disaster Set Off by Colliding Land Masses
大陆板块碰撞引发地震灾难

By KENNETH CHANG
Published: May 13, 2008
肯尼思·常   2008.5.13

The earthquake in the Sichuan Province of China on Monday was a result of a
continuing collision between India and Asia.
据称中国四川省12日发生的地震为南亚次大陆与亚洲大陆持续挤压碰撞引发。

India, once a giant island before crashing into the underside of Asia about
40 million to 50 million years ago, continues to slide north at a
geologically quick pace of two inches a year. The tectonic stresses push up
the Himalaya Mountains and generate scores of earthquakes from Afghanistan
to China.
距今4000-5000万年前，印度还没有开始向亚洲漂移冲撞以前曾是巨大的孤岛，现今它以
每年接近5厘米的较快地质运动速度持续向北挤压。巨大的构造压力隆升了喜马拉雅山并
造成了阿富汗至中国一线频发的地震灾害。

In the eastern part of the region where Asia and India collide, the Tibetan
plateau is pushing southeast against the flat Sichuan basin. “It’s
definitely a seismic area,” said Julie Martinez, a geophysicist with the
United States Geological Survey’s National Earthquake Information Center in
Boulder, Colo.
在亚洲与南亚次大陆冲撞的东部，青藏高原产生了向四川盆地的推力。“那里显然会是地
震活动区”，美国地质调查所国家地震信息中心地球物理学家朱力·马丁内斯称，该中心
位于科罗拉多州布德市。


On Monday afternoon, an upward thrust fault broke, generating an earthquake
with a preliminary magnitude of 7.9 . An aftershock with a preliminary
magnitude of 6.0 followed 15 minutes later, and smaller aftershocks continue
in the area.
12日下午，一组逆冲断裂触发了此次初测震级7.9级的大地震。15分钟后发生6.0级（初测
）余震，随后这一地区陆续发生小规模余震

The epicenter lay in the Longmen Shan, mountains that rise steeply to the
west of Chengdu, the capital of Sichuan. B. Clark Burchfiel, a professor of
geology at the Massachusetts Institute of Technology, who performed research
in the area, said that section of the Longmen Shan fault would not have been
expected to generate an earthquake of that magnitude.
此次地震震中位于四川省省会成都市以西高耸的龙门山山脉。麻省理工学院地质学教授B
·
克拉克·布赫菲曾从事这一地区的研究，他表示龙门山断裂应该不能够引起如此强烈的大
震。

“It’s active, but I wouldn’t have put an earthquake that big on it,” he
said.

他说，“龙门山属于活动断裂，但我想他不会诱发这样大规模的地震。”

However, much of the visible tectonic history along the fault has been
obliterated by landslides, and the earthquake on Monday may have occurred
along a previously unknown fault, he said.
事实上，这一断裂带附近的很多可见的构造变动记录已经被山体滑坡掩蔽。克拉克教授称
“昨天的地震可能由先前未查明的断裂引发。”