Older Volcanic Eruptions
Volcanoes were more destructive in ancient history, not because they were bigger, but because the carbon dioxide they released wiped out life with greater ease.
Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals, but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise, the older the massive volcanic eruptions were, the more damage they seemed to do. He calculated the "killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava that they produced. He found that size for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.
The Permian extinction, for example, which happened 250 million years ago, is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide. The global warming that followed wiped out 80 per cent of all marine genera at the time, and it took 5 million years for the planet to recover. Yet 60 million years ago, there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within ten thousands of years. "The most recent ones hardly have an effect at all," Wignall says. He ignored the extinction which wiped out the dinosaurs 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid. He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.
Vincent Courtillot, director of the Paris Geophysical Institute in France, says that Wignall's idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced, and that lava volume may not necessarily correspond to carbon dioxide emissions.
词汇：
Bunch n. 群
Marathon n. 马立松;耐力活动
fundraiser n. 募捐
weather v. 经受风雨
bureaucracy n. 官僚机构
注释：
1.Putting a bunch of college students in charge of a$300，000 Dance Marathon，fundraiser surely sounds a bit risky.让一群大学生去负责募集30万美元的马拉松式的跳舞活动，这种募捐听起来肯定有点儿冒险。“putting...in charge of...”是“让……负责”。
2.Yvonne Fangmeyer, director of the student organization office at the University of Wisconsin, conducted a survey in February of students involved in campus organizations.Yvonne Fangmeyer是威斯康星大学学生组织办公室主任，在二月组织了一次学生参加校园组织的调查。“a survey of students involved in campus organizations”太长了，所以“in February”插到了中间。
3.“teamup”是“参加”。
练习：
1. An extracurricular activity like raising a fund of $300,000 is risky because most student leaders
A) are lazy.
B) are stupid.
C) are not rich enough.
D) wilt not take an interest in it.
2. American students join campus organizations mostly for
A) making a difference.
B) gaining experience.
C) building friendship.
D) improving their resumes.
3. Who is Katie Rowley?
A) She's a senior professor.
B) She's a senior student.
C) She's a senior official.
D) She's a senior citizen
to carry an activity through to a successful end?
A) Passion.
B) Money.
C) Power.
D) Fame.
5. The phrasal verb fatten up in paragraph 6 could be best replaced by
A) invent.
B) rewrite.
C) polish.
D) complete.
答案与题解：
1.D 问题问的是：像募集30万美元的的课外活动有点冒险是为什么?答案可以从第二段的第一句话中找到。第一句话是这么说的：大多数学生头头并不想在它们不感兴趣的事上花大量的时间。
2.C 问题问的是：美国学生参加校园组织的主要目的是什么?答案可以从第三段找到。第三段是这么说的：威斯康星大学学生组织办公室主任Yvonne Fangmeyer在二月组织了一次学生参加校园组织的调查。她说，寻求友谊是最经常列举的理由。
3.B问题问的是：Katie Rowley是谁?文章提到了好几个人，Katie Rowley是其中的一个。第五段讲到了Katie Rowley。“a Wisconsin senior”是“威斯康星四年级学生”。
4.A 问题问的是：为了把一项活动顺利地贯彻到底学生头头需要什么?答案可以从倒数第二段找到。第一句话是这么说的：但是，如果没有激情(passion)，学生头头试图经受急风暴雨的考验是会有困难的。
5.C 问题问的是：哪个词替换第6段中的“fatten up”最合适?“fatten up”原义是“使
人或动物变肥”，在这里可以解释为使一个人的履历更充实一些，因此也好看一些。因此意思上最接近的是“polish”(润色)。
译文：
远古火山喷发
古代的火山更具杀伤力，不是因为它们更大，而是因为它们释放出来的二氧化碳更容易把人杀死。
来自里兹大学的Paul Wignall正在调查火山爆发和大规模物种灭绝之间的联系。不是所有的火山都会造成大量动物死亡。但在过去的三亿年间，巨大的火山岩石的形成都伴随着大规模种族灭绝。让他惊奇的是，远古的火山造成的破坏更大。他通过比较火山释放出的熔岩的体积与杀死生命的比例计算这些火山的杀伤效力。他发现，体积相同的情况下，老远古火山要比近期火山的杀伤力大十倍。
例如，发生在两亿五千年前的二叠纪物种灭绝就与西伯利亚的火山爆发发生在同一时期。当时的火山岩大约覆盖了西欧那么大的面积。当时火山释放出了大约100亿吨梯恩梯的二氧化碳，随之而来的全球变暖杀死了80％的海洋生物。500万年以后，地球才恢复到原来的状态。然而，6000年前，火山大规模爆发，以及而后的全球变暖并没有带来种族灭绝。一些动物确实消失了，但几万年以后，地球又恢复到以前的水平。“最近的一次火山爆发基本上没带来什么影响。”Wignall称。他并没有将650万年前的恐龙灭绝计算在内，因为大部分的科学家认为那是有小行星撞击地球所引起的。他认为，远古火山之所以杀伤力大是因为近期的生物能够更好的适应二氧化碳含量上升。
法国巴黎地理研究所的所长Vincent Courtillot称Wignall的观点很具争议性，并且很难做出这样的计算。他指出火山爆发的杀伤力是由其持续长度所决定的。并且很难知道是否大规模爆发会持续上百万年。他补充道，很难计算远古火山灰喷发多少火山岩，并且火山岩的数量也不一定和二氧化碳释放数量相一致。
