美国国家公共电台 NPR Asteroid Impact That Wiped Out The Dinosaurs Also Caused Abrupt Global Warming

 

ARI SHAPIRO, HOST:

A giant asteroid¹ slammed into Earth about 65 million years ago. That impact killed off the dinosaurs². And now scientists say it had another major effect on the planet, one that's a cautionary tale. Here's NPR's Nell Greenfieldboyce.

NELL GREENFIELDBOYCE, BYLINE³: The so-called Chicxulub asteroid was more than 5 miles wide. When it crashed into our planet, there was chaos⁴.

PAGE QUINTON: You had a huge asteroid hitting the ocean at high speed. That's going to cause tsunamis⁵.

GREENFIELDBOYCE: Page Quinton is a geologist⁶ at the State University of New York in Potsdam. She says the impact also set off massive wildfires and created a global cloud of dust and debris⁷ that blocked the sun for months or decades.

QUINTON: So on the short term, there's a variety of very, like, quick, scary stuff going down. And the dinosaurs of course, you know, feel that impact.

GREENFIELDBOYCE: What she and some colleagues wanted to know was the long-term impact from carbon dioxide. Carbon dioxide, as we all know, is a greenhouse gas, and a lot of it was released by those fires and vaporized rock. Ken⁸ MacLeod is a paleontologist at the University of Missouri. He turned to an unusual place to find a record of past temperatures - tiny bits of fossilized fish so tiny they can look like sand or crud.

KEN MACLEOD: But under the microscope, they are unequivocally fish fossils. So there are these millimeter-, half-millimeter-long little teeth, and under the microscope, they're gorgeous. There are little scales or bits of bone.

GREENFIELDBOYCE: It turns out that their chemistry is different depending on the temperatures when they lived. He and Quinton analyzed⁹ fossils from before and after the asteroid impact, and what they found is striking. After the impact, global temperatures rose by about 5 degrees Celsius¹⁰.

MACLEOD: And then it stays at that level for an interval¹¹ that spans a hundred thousand years.

GREENFIELDBOYCE: He sees a lesson here that's relevant for today.

MACLEOD: The carbon dioxide that was put into the atmosphere after the impact was probably introduced on the time scale of years to decades, which is pretty comparable to the timescale on which we're introducing CO2.

GREENFIELDBOYCE: By burning fossil fuels. He's not the only one to make this connection. Brian Huber is a paleontologist at the Smithsonian's National Museum of Natural History.

BRIAN HUBER: We are basically replaying that instantaneous event.

GREENFIELDBOYCE: He says how long the warming persisted was stunning¹², and that's why he found these results in the journal Science a little bit frightening. Nell Greenfieldboyce, NPR News.

1 asteroid   

n.小行星；海盘车(动物)

参考例句：

• Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。
• It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小，但这样的危险还是存在的。

2 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

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 chaos   

n.混乱，无秩序

参考例句：

• After the failure of electricity supply the city was in chaos.停电后，城市一片混乱。
• The typhoon left chaos behind it.台风后一片混乱。

5 tsunamis   

n.海啸( tsunami的名词复数 )

参考例句：

• Our oceans are alive with earthquakes, volcanoes, and more recently, tsunamis. 海中充满着地震、火山，包括最近发生的海啸。 来自常春藤生活英语杂志-2006年2月号
• Please tell me something more about tsunamis! 请您给我讲讲海啸吧！ 来自辞典例句

6 geologist   

n.地质学家

参考例句：

• The geologist found many uncovered fossils in the valley.在那山谷里，地质学家发现了许多裸露的化石。
• He was a geologist,rated by his cronies as the best in the business.他是一位地质学家，被他的老朋友们看做是这门行当中最好的一位。

7 debris   

n.瓦砾堆，废墟，碎片

参考例句：

• After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
• Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上，导致蛀牙。

8 ken   

n.视野，知识领域

参考例句：

• Such things are beyond my ken.我可不懂这些事。
• Abstract words are beyond the ken of children.抽象的言辞超出小孩所理解的范围.

9 analyzed   

v.分析( analyze的过去式和过去分词 )；分解；解释；对…进行心理分析

参考例句：

• The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
• The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程，因为对他来说，爱是个不可分析的迷。 来自《简明英汉词典》

10 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

11 interval   

n.间隔，间距；幕间休息，中场休息

参考例句：

• The interval between the two trees measures 40 feet.这两棵树的间隔是40英尺。
• There was a long interval before he anwsered the telephone.隔了好久他才回了电话。

12 stunning   

adj.极好的；使人晕倒的

参考例句：

• His plays are distinguished only by their stunning mediocrity.他的戏剧与众不同之处就是平凡得出奇。
• The finished effect was absolutely stunning.完工后的效果非常美。