ImageVerifierCode 换一换
格式:DOC , 页数:8 ,大小:18.89KB ,
资源ID:2993965      下载积分:15 文钱
快捷下载
登录下载
邮箱/手机:
温馨提示:
快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。 如填写123,账号就是123,密码也是123。
特别说明:
请自助下载,系统不会自动发送文件的哦; 如果您已付费,想二次下载,请登录后访问:我的下载记录
支付方式: 支付宝    微信支付   
验证码:   换一换

加入VIP,省得不是一点点
 

温馨提示:由于个人手机设置不同,如果发现不能下载,请复制以下地址【https://www.wenke99.com/d-2993965.html】到电脑端继续下载(重复下载不扣费)。

已注册用户请登录:
账号:
密码:
验证码:   换一换
  忘记密码?
三方登录: QQ登录   微博登录 

下载须知

1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。
2: 试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。
3: 文件的所有权益归上传用户所有。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 本站仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

版权提示 | 免责声明

本文(The Cloud That Closed A Continent.doc)为本站会员(11****ws)主动上传,文客久久仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知文客久久(发送邮件至hr@wenke99.com或直接QQ联系客服),我们立即给予删除!

The Cloud That Closed A Continent.doc

1、The Cloud That Closed A ContinentAs volcanic eruptions go, Icelands Eyjafjallajokull wont break the records. Icelanders dismiss the normally sleepy Eyjafjallajokull as a “weary old man,” and in fact few people outside the volcanology community or the 800 or so Icelandic farmers who needed to be evac

2、uated noticed when the volcano began spewing lava on March 20. Most likely it would have remained that way - a brief tourist attraction and a footnote in a few grad students dissertations before the earth quieted again.But thats not quite what happened. Instead, on April 14, a new and stronger erupt

3、ion on Eyjafjallajokull exploded through a glacial ice cap, throwing a vast plume of volcanic ash around 7 miles (11 km) into the atmosphere, high enough to be carried for thousands of miles. And then, as if on cue, the winds shifted, blowing to the east and south, sending the tower of ash toward no

4、rthern Europe and some of the most crowded airspace on the planet. “It was an eruption at the right place at the right time,” says Marcus Bursik, a volcanologist at the University at Buffalo. “Or, I guess, really, the other way around.”Indeed, for anyone attempting to travel to, from or within Europ

5、e - or anyone who owns stock in an airline - it was definitely the wrong place at the wrong time. Because volcanic ash can ruin the jet engines of aircraft, European air-traffic controllers began shutting down the continents airspace as the high-altitude cloud loomed. By April 15, planes were ground

6、ed and the skies above Europes cities were eerily quiet. As the cloud metastasized across the continent, nervous bureaucrats kept much of its airspace closed for almost five days, resulting in the cancellation of more than 100,000 flights and the stranding of hundreds of thousands of travelers in ai

7、rports around the world. With a third of the industry down, it was the worst global travel disruption since World War II, as the lifeline wed all come to take for granted was suddenly snapped.” These are extraordinary circumstances beyond all airlines control,” says Willie Walsh, CEO of British Airw

8、ays, which was losing up to $30 million a day during the shutdown.But the impact of the volcanic crisis went far beyond the inconvenience of stranded vacationers and the sprained tongues of newscasters trying to pronounce Eyjafjallajokull. (For the record, its Ey-ya-fyat-lah-yoh-kuht.) The airline i

9、ndustry, already pummeled by the recession, has lost nearly $2 billion. TUI Travel, Europes biggest tour operator, had 100,000 customers marooned overseas and was losing $9 million a day as it scrambled to get them home. Kenyan farmers, who supply one-third of Europes fresh flowers, were losing $2 m

10、illion a day as their blooms withered on Nairobi runways. Transplants of bone marrow - which needs to be implanted within 72 hours of harvesting, or else the cells will die - were delayed, putting cancer patients lives at risk. Hundreds of runners from overseas were unable to make it to the starting

11、 line of the Boston Marathon on April 19, including Moroccan Olympian Abdellah Falil, who was stuck in Paris. Oxford University bigwigs, in New York for a biannual outreach weekend, wondered how to get back home for the summer term, and world leaders couldnt fly to Poland for the funeral of Polish P

12、resident Lech Kaczynski on April 18. “Its nature,” says Joy Martinez, 29, a New Yorker who shifted her wedding at the last minute from France to Bali because of the volcano. “And you cant fight nature.”Understanding why Eyjafjallajokull has wreaked such havoc on Europe requires a little basic volcan

13、ology - which volcanologists, thoroughly enjoying their week in the spotlight, are only too happy to provide. Eyjafjallajokull means “island mountain glacier” in Icelandic, and the top of the ice cap covers the volcanos peak. The ice is the thing: the weight of the glacier atop the volcano helps the

14、 magma inside build to a higher pressure, so on April 14, when the mountain had its second eruption, it blew with enough force to send volcanic gases and ash miles into the sky. And the cold water from the melted ice quickly chilled the lava, fragmenting it into tiny glass particles that could be ca

15、rried away in the plume. (Thats what ash really is - not rock dust but little shreds of silica.) The ash plume reached the troposphere, some 35,000 ft. (almost 11 km) up, high enough to hang at the altitude where passenger planes cruise and high enough to be blown to northern Europe and beyond. “Its

16、 a minor eruption in the grand scheme of things,” says Jon Davidson, an earth scientist at Durham University in Britain. “But there was a conspiracy of factors that made it worse.” Ice and wind were just two of those factors; our dependence on air travel was the other. If you wanted to turn a $300 m

17、illion jumbo jet into scrap metal, you couldnt find a faster way to do it than flying it through the heart of a volcanic cloud. Heavy ash can sandblast the windows, leaving them impossible to see through. But the real threat is to the jet engines: ash is sucked into the hot combustion chamber, where

18、 it melts into molten glass, clogging the machinery, degrading the fan blades and potentially causing the engine to flame out. Thats exactly what happened to a 1982 British Airways flight that ran into an undetected volcanic-ash cloud off Indonesia, losing all four engines before it was able to make

19、 an emergency landing.But even very thin, dispersed ash clouds can badly damage a plane. In 2000 a NASA research jet flew through a high-altitude ash cloud without the pilots realizing it. The flight continued without incident, but when scientists took apart the engines later, they discovered $3.2 m

20、illion worth of damage that could have soon crippled the plane. “Ash can definitely do some real damage to your engines,” says Thomas Grindle, chief of aircraft maintenance at NASAs Dryden Flight Research Center in Edwards, Calif., who wrote a report on the incident. “And we didnt even know it was h

21、appening at the time.” Pilots can fly around or under an ash cloud, but its difficult to measure the exact boundaries of the plume, and as writer and amateur pilot James Fallows puts it, flying at low altitude is “like driving cross-country in first gear.” Airlines have an official zero-tolerance ap

22、proach to volcanic ash, so when scientific models showed the plume spreading across Britain and much of northern Europe in the hours after the eruption, one airport after another benched its planes where they sat. And as the plume lingered over Europe and airports remained closed for two days, then

23、three and then longer, utter travel chaos hit, with hundreds of thousands of people around the world realizing they were stranded far from home - and quite suddenly in the pre-jet era. “These kinds of eruptions happened all the time in the past,” says Dougal Jerram, an earth scientist at Durham Univ

24、ersity. “But the disruption is a product of how we live today.” And what a disruption, as stranded travelers used every means at their disposal to make it home. German Chancellor Angela Merkel, returning from San Francisco, was forced to fly to Grand Forks, N.D., then to Lisbon, then to Rome, and th

25、en travel by car and bus to Germany - an odyssey that took nearly three days. The British government sent warships from the Royal Navy to pick up stranded vacationers in Spain, while English TV host Dan Snow used Twitter to organize a second Dunkirk evacuation across the Channel for Brits stuck in C

26、alais, France. (It didnt go as well as the first. French immigration officials put a quick stop to the rescue.) Travelers crowded train and bus stations, hoping to get scarce tickets home - or to one of the few European airports that were still operating. To make it back to New York City from London

27、, Kate Winn, a TV executive with the A scientists cant easily measure how dense a plume really is, nor is there any set limit for how much ash a plane can safely fly through. More research is needed - something Louisiana Governor Bobby Jindal, who once famously mocked the federal spending of million

28、s of dollars on volcano monitoring, might want to remember. “If we spend $100 million now, we might actually be able to prevent events that would cost billions,” says Benjamin Edwards, head of the earth-sciences department at Dickinson College in Pennsylvania. But theres a deeper lesson to Eyjafjallajokull: the earth can still surprise us. As complicated as our transcontinental supply chains and holidays have become, a single shrug from the planet can disrupt everything and leave us marooned far from home.

Copyright © 2018-2021 Wenke99.com All rights reserved

工信部备案号浙ICP备20026746号-2  

公安局备案号:浙公网安备33038302330469号

本站为C2C交文档易平台,即用户上传的文档直接卖给下载用户,本站只是网络服务中间平台,所有原创文档下载所得归上传人所有,若您发现上传作品侵犯了您的权利,请立刻联系网站客服并提供证据,平台将在3个工作日内予以改正。