首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
One fine day about 74 000 years ago, a giant volcano on Sumatra blew its top. The volcano, named Toba, may have ejected(喷射)1 000
One fine day about 74 000 years ago, a giant volcano on Sumatra blew its top. The volcano, named Toba, may have ejected(喷射)1 000
admin
2013-10-22
33
问题
One fine day about 74 000 years ago, a giant volcano on Sumatra blew its top. The volcano, named Toba, may have ejected(喷射)1 000 times more rock and other material than Mount St. Helens in Washington state did in 1980. In the process, it cooled the climate by at least 10°C, causing a global famine.
Paleoclimate(古气候)evidence suggests that the Toba eruption, which occurred during the last ice age, emitted lots of sulfur dioxide—vastly more than Mount St. Helens did. The eruption also seems to have coincided with the start of a 1000-year period of even colder temperatures. Some scientists have suggested that Toba caused the deep freeze and that perhaps such an event happening today could bring on a new ice age. But models developed by National Aeronautics and Space Administration and the National Center for Atmospheric Research in Boulder, Colorado, argue otherwise.
Researchers led by climatologist Alan Robock of Rutgers University in New Brunswick, New Jersey, ran scenarios that featured eruptions producing up to several times more sulfur dioxide than Toba. The result, published 27 May in the Journal of Geophysical Research—Atmospheres, was a cooler climate that lasted only a few decades. So the 1000-year cold spell was probably part of the natural cycle that has produced more than a dozen ice ages over the past couple of million years.
"The results virtually eliminate mega(非常大的)volcanic eruptions as one of the key drivers of global-scale glaciation," says climatologist Ellen Mosley-Thompson of Ohio State University in Columbus, who was not involved in the study. So, paleoclimatologists should focus on more likely climate coolers, she says, such as changes in ocean circulation or cyclical variations in Earth’s orbit around the sun.
Still, if Toba erupted today like it did in the past, the results would be catastrophic. Although the volcano isn’t expected to blow its top for thousands of years, Robock and colleagues estimate a megaeruption could lower global temperatures by as much as 17℃ for several years, followed by a recovery to normal conditions that could take decades. That would hit the human population with the double whammy of dramatically reduced agricultural production and widespread loss of vegetation, leading to widespread food shortages and starvation.
Which view did Alan Robock’s research want to verify?
选项
A、Ancient volcano eruptions caused the Earth to freeze.
B、The 1000-year cooler time was not caused by Toba eruption.
C、Ice age is part of the natural cycle of the volcanic eruptions.
D、There won’t be any new ice age in the future.
答案
B
解析
推理判断题。由定位句可知,模拟实验的结果显示:千年寒冷期很可能是自然循环的一部分,这种循环在过去的几百万年中产生了不下12个冰河时代。结合前一句中的内容可知,火山爆发所导致的气候变冷仅能持续几十年,因此可以推断,B)“千年寒冷期不是多巴火山爆发引起的”符合文意。
转载请注明原文地址:https://kaotiyun.com/show/Apc7777K
0
大学英语四级
相关试题推荐
Libyahadeverbeenregardedasoneoftheterrorism-supportingcountriesbefore.BytakingadvantageoftheUnitedStates’___
Alandfreefromdestruction,pluswealth,naturalresources,andlaborsupply—allthesewereimportant【C1】______inhelpingEngl
EachUSDAbeefgradeisameasureofadistinctlevelofquality.Becausebeefcanvarysomuchin【S1】______,ittakeseightg
JinlingHotel,whereIstayedduringmyfirstvisittoNanjing,___________(座落在)onHanzhongRoad.
Todaywetalkaboutthedifferencebetweenacollegeandauniversity.Collegesanduniversitieshavealotin【B1】______.Theyp
Todaywetalkaboutthedifferencebetweenacollegeandauniversity.Collegesanduniversitieshavealotin【B1】______.Theyp
Accordingtothepassage,these119applicantsforHarvardBusinessSchoolwouldberejectedbecause______.AccordingtoKimCl
Onefinedayabout74000yearsago,agiantvolcanoonSumatrablewitstop.Thevolcano,namedToba,mayhaveejected(喷射)1000
SevenWaystoSavetheWorldA)Forgettheoldideathatconservingenergyisaformofself-denial—ridingbicycles,dimmingthe
With10,600bicyclesincirculation,Pariscityofficialsarehopingtheprogramwillprovidepeoplewithmoreenvironmentallyf
随机试题
少尿是指24小时尿量少于
易破坏河豚毒素的条件是
植物油:水:胶液体石蜡:水:胶
设甲、乙、丙、丁四国就流经四国的多国河流的航行事项于2007年缔结条约,规定缔约国船舶可以在四国境内的该河流中通航。2012年,甲国新当选的政府宣布:因乙国政府未能按照条约的规定按时维修其境内航道标志,所以甲国不再受上述条约的拘束,外国船舶进入甲国境内的该
社会监理是建立完善的公路工程质量保证体系的前提条件。()
斩假石表面平整度的允许偏差值,下列符合规范规定的是()。
应急演练参演人员所承担的具体任务主要包括()。
马克思说:“哲学家们只是用不同的方式解释世界,而问题在于改变世界”。下列表述中最符合马克思这句话原意的是
“无论历史的结局如何,人们总是通过每一个人追求他自己的、自觉预期的目的来创造他们的历史,而这许多按不同方向活动的愿望及其对外部世界的各种各样作用的合力,就是历史。”这段话说明
Youhavereadonlinethenewswhichsays,"ChinalaunchedacrackdownonplasticbagsonJanuary8,2008,banningproductionof
最新回复
(
0
)