美国国家公共电台 NPR Mexico City Doomed By Its Geology To More Earthquakes

 

ARI SHAPIRO, HOST:

Rescuers in and around Mexico City are still digging through rubble¹, searching for survivors² of yesterday's massive earthquake. It happened at 1 p.m. local time, in the middle of the school and work day. Buildings fell across five states in the country and in the capital. At least 225 people have died.

This is the second major earthquake in Mexico in less than two weeks, and it came 32 years to the day after another deadly quake. NPR science correspondent Christopher Joyce says Mexico City sits in one of the most quake-prone areas of the world.

CHRISTOPHER JOYCE, BYLINE³: Geologically speaking, Mexico City is not built in a very good place. Just to the west, a huge slab⁴ of the earth's crust called the Cocos Plate is grinding relentlessly⁵ toward North America, but it's running into an even bigger slab, the North American Plate. So the Cocos Plate is shoving itself underneath⁶ its northern neighbor. Lots of faults lie along and near the junction⁷ of these two plates like stitches in the seam of a baseball. When the faults slip from all that continental⁸ grinding, quakes happen. This is what surrounds Mexico City. But there's another problem, as geophysicist Gavin Hayes with the U.S. Geological Survey points out. The city sits on a dry lake bed, and that's not good.

GAVIN HAYES: So you've got a lot of soft sediments⁹. And when the energy from the earthquake comes into that, those basins really kind of amplify¹⁰ that shaking like a bowl of jelly shaking around. And it just keeps on reverberating¹¹.

JOYCE: Hayes also points out that shallow quakes in this region often create earthmoving waves at a frequency that's especially damaging to 10- to 20-story buildings. These buildings vibrate in sync with those waves like a tuning¹² fork.

HAYES: A lot of buildings in Mexico City are at that kind of 10- to 20-story level, and so they're just at the right height to be quite vulnerable.

JOYCE: The two quakes this month were on the same tectonic plate but several hundred miles apart. Hayes says it's not likely the first quake triggered a second one so far away, but it's possible. Mexico City has strengthened many buildings since the 1985 quake which killed more than 5,000 people, and it has designed an early warning system that detects the first vibrations¹³ from a quake to give people an earlier warning. But like many cities around the Pacific Rim¹⁴ - San Francisco, Tokyo, Manila - it's sitting on ground that's not going to stop moving. Christopher Joyce, NPR News.

1 rubble   

n.（一堆）碎石，瓦砾

参考例句：

• After the earthquake,it took months to clean up the rubble.地震后，花了数月才清理完瓦砾。
• After the war many cities were full of rubble.战后许多城市到处可见颓垣残壁。

2 survivors   

幸存者，残存者，生还者( survivor的名词复数 )

参考例句：

• The survivors were adrift in a lifeboat for six days. 幸存者在救生艇上漂流了六天。
• survivors clinging to a raft 紧紧抓住救生筏的幸存者

3 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

4 slab   

n.平板，厚的切片；v.切成厚板，以平板盖上

参考例句：

• This heavy slab of oak now stood between the bomb and Hitler.这时笨重的橡木厚板就横在炸弹和希特勒之间了。
• The monument consists of two vertical pillars supporting a horizontal slab.这座纪念碑由两根垂直的柱体构成，它们共同支撑着一块平板。

5 relentlessly   

adv.不屈不挠地；残酷地；不间断

参考例句：

• The African sun beat relentlessly down on his aching head. 非洲的太阳无情地照射在他那发痛的头上。
• He pursued her relentlessly, refusing to take 'no' for an answer. 他锲而不舍地追求她，拒不接受“不”的回答。

6 underneath   

adj.在...下面，在...底下；adv.在下面

参考例句：

• Working underneath the car is always a messy job.在汽车底下工作是件脏活。
• She wore a coat with a dress underneath.她穿着一件大衣，里面套着一条连衣裙。

7 junction   

n.连接，接合；交叉点，接合处，枢纽站

参考例句：

• There's a bridge at the junction of the two rivers.两河的汇合处有座桥。
• You must give way when you come to this junction.你到了这个路口必须让路。

8 continental   

adj.大陆的，大陆性的，欧洲大陆的

参考例句：

• A continental climate is different from an insular one.大陆性气候不同于岛屿气候。
• The most ancient parts of the continental crust are 4000 million years old.大陆地壳最古老的部分有40亿年历史。

9 sediments   

沉淀物( sediment的名词复数 )； 沉积物

参考例句：

• When deposited, 70-80% of the volume of muddy sediments may be water. 泥质沉积物沉积后，体积的70-80％是水。
• Oligocene erosion had truncated the sediments draped over the dome. 覆盖于穹丘上的沉积岩为渐新世侵蚀所截削。

10 amplify   

vt.放大，增强；详述，详加解说

参考例句：

• The new manager wants to amplify the company.新经理想要扩大公司。
• Please amplify your remarks by giving us some examples.请举例详述你的话。

11 reverberating   

回响，回荡( reverberate的现在分词 )； 使反响，使回荡，使反射

参考例句：

• The words are still ringing [reverberating] in one's ears. 言犹在耳。
• I heard a voice reverberating: "Crawl out! I give you liberty!" 我听到一个声音在回荡：“爬出来吧，我给你自由！”

12 tuning   

n.调谐，调整，调音v.调音( tune的现在分词 )；调整；（给收音机、电视等）调谐；使协调

参考例句：

• They are tuning up a plane on the flight line. 他们正在机场的飞机跑道上调试一架飞机。 来自《简明英汉词典》
• The orchestra are tuning up. 管弦乐队在定弦。 来自《现代汉英综合大词典》

13 vibrations   

n.摆动( vibration的名词复数 )；震动；感受；（偏离平衡位置的）一次性往复振动

参考例句：

• We could feel the vibrations from the trucks passing outside. 我们可以感到外面卡车经过时的颤动。
• I am drawn to that girl; I get good vibrations from her. 我被那女孩吸引住了，她使我产生良好的感觉。 来自《简明英汉词典》

14 rim   

n.(圆物的)边，轮缘；边界

参考例句：

• The water was even with the rim of the basin.盆里的水与盆边平齐了。
• She looked at him over the rim of her glass.她的目光越过玻璃杯的边沿看着他。