Antarctica-in from the cold?
A A little over a century ago, men of the ilk of Scott, Shackleton and Mawson battled against Antarctica's blizzards, cold and deprivation. In the name of Empire and in an age of heroic deeds they created an image of Antarctica that was to last well into the 20th century - an image of remoteness, hardship, bleakness and isolation that was the province of only the most courageous of men. The image was one of a place removed from everyday reality, of a place with no apparent value to anyone.
B As we enter the 21st century, our perception of Antarctica has changed. Although physically Antarctica is no closer and probably no warmer, and to spend time there still demands a dedication not seen in ordinary life, the continent and its surrounding ocean are increasingly seen to an integral part of Planet Earth, and a key component in the Earth System. Is this because the world seems a little smaller these days, shrunk by TV and tourism, or is it because Antarctica really does occupy a central spot on Earth's mantle? Scientific research during the past half century has revealed - and continues to reveal - that Antarctica's great mass and low temperature
exert a major influence on climate and ocean circulation, factors which influence the lives of millions of people all over the globe.
C Antarctica was not always cold. The slow break-up of the super-continent Gondwana with the northward movements of Africa, South America, India and Australia eventually created enough space around Antarctica for the development of an Antarctic Circumpolar Current (ACQ, that flowed from west to east under the influence of the prevailing westerly winds. Antarctica cooled, its vegetation perished, glaciation began and the continent took on its present-day appearance. Today the ice that overlies the bedrock is up to 4km thick, and surface temperatures as low as - 89.2deg C have been recorded. The icy blast that howls over the ice cap and out to sea - the so-called katabatic wind - can reach 300 km/hr, creating fearsome wind-chill effects.
D Out of this extreme environment come some powerful forces that reverberate around the world. The Earth's rotation, coupled to the generation of cells of low pressure off the Antarctic coast, would allow Astronauts a view of Antarctica that is as beautiful as it is awesome. Spinning away to the northeast, the cells grow and deepen, whipping up the Southern Ocean into the mountainous seas so respected by mariners. Recent work is showing that the temperature of the ocean may be a better predictor of rainfall in Australia than is the pressure difference between Darwin and Tahiti - the Southern Oscillation Index. By receiving more accurate predictions, graziers in northern Queensland are able to avoid overstocking in years when rainfall will be poor. Not only does this limit their losses but it prevents serious pasture degradation that may take decades to repair. CSIRO is developing this as a prototype forecasting system, but we can confidently predict that as we know more about the Antarctic and Southern Ocean we will be able to enhance and extend our predictive ability.
E The ocean's surface temperature results from the interplay between doep- wa,ter temperature, air temperature and ice. Each winter between 4 and 19 million square km of sea ice form, locking up huge quantities of heat close to the continent.Only now can we start to unravel the influence of sea ice on the weather that is experienced in southern Australia. But in another way the extent of sea ice extends its influence far beyond V Antarctica. Antarctic krill - the small shrimp-like crustaceans that are the staple diet for baleen whales, penguins, some seals, flighted sea birds and many fish - breed well in years when sea ice is extensive and poorly when it is not. Mary species of baleen whales and flighted sea birds migrate between the hemispheres and when the krill are less abundant they do not thrive.
F The circulatory system of the world's oceans is like a huge conveyor belt, moving water and dissolved minerals and nutrients from one hemisphere to the other, and from the ocean's abyssal depths to the surface. The ACC is the longest current in the world, and has the largest flow. Through it, the deep flows of the Atlantic, Indian and Pacific Oceans are joined to form part of a single global thermohalinc circulation. During winter, the howling katabatics sometimes scour the ice off patches of the sea's surface leaving Large ice- locked lagoons, or 'polynyas'. Recent research has shown that as fresh sea ice forms, it is continuously stripped away by the wind and may be blown up to 90km in a single day. Since only fresh water freezes into ice, the water that remains bccom.cs increasingly salty and dense, sinking until it spills over the continental shelf. Cold water carries more oxygen than warm water, so when it rises, well into the northern hemisphere, it reoxygenates and revitalises the ocean. The state of the northern oceans, and their biological productivity, owe much to what happens in the Antarctic.
The reading Passage has ten paragraphs A-J.
Which paragraph contains the following information?
Write the correct letter A-F, in boxes 14-18 on your answer sheet.
14. introduction of a millman under awards
15. the definition of an important geographical term
16. a rival against Harrison’s invention emerged
17. problems of sailor encountered in identifying the postion on the sea
18. economic assist from another counterpart
Please match the natural phenomenon with correct determined factor Choose the correct answer from the box; Write the correct letter A-F in boxes 19-21 on your answer sheet.
19. Globally, mass Antarctica’s size and _________ influence the climate change.
20. __________ contributory to western wind.
21. Southern Oscillation Index based on air pressure can predict __________ in Australia.
A Antarctic Circumpolar Current (ACC)
B katabatic winds C rainfall
D temperature E glaciers
Choose the correct letter, A,B,C or D.
Write your answers in boxes 22-26 on you answer sheet.
22 In the paragraph B, the author want to tell which of the
following truth about Antarctic?
A To show Antarctica has been a central topic of global warming in Mass media
B To illustrate its huge see ice brings food to million lives to places in the world
C To show it is the heart and its significance to the global climate and current
D To illustrate it locates in the central spot on Earth geographically
23 Why do Australian farmers Keep an eye on the Antarctic ocean temperature ?
A Help farmers reduce their economic or ecological losses
B Retrieve grassland decreased in the overgrazing process
C Prevent animal from dying
D A cell provides fertilizer for the grassland
24 What is the final effect of katabatic winds?
A Increase the moving speed of ocean current
B Increase salt level near ocean surface
C Bring fresh ice into southern oceans
D Pile up the mountainous ice cap respected by mariners
25 The break of the continental shelf is due to the
A Salt and density increase
B Salt and density decrease
C global warming resulting a rising temperature
D fresh ice melting into ocean water
26 The decrease in number of Whales and seabirds is due to
A killers whales arc more active around
B Sea birds are affected by high sea level salty
C less sea ice reduces productivity of food source
D seals fail to reproduce babies
14Weather prediction, agricultureD段第五，六句D段第五六两句提到“通过接收更为准确的预测，放牧人能够·······。这不仅会减少他们的损失，还可以阻止严重的草场退化”
15Sea ice, ocean’s vitalityF段倒数第二句F段倒数第二句中关键词“it reoxygenates and revitalizes the ocean” it(Antarctic sea ice)给海洋补充氧气和重新激活海洋
16Food chain, animals living patternE段最后两句E段第三句进行转折了之后的两句，进一步说明
“Antarctic krill (that are the staple diet for baleen whales, penguins, some seals, flighted sea birds and many fish)在海冰充裕时，很丰富;当海冰减少时，数量减少导致许多长须鲸和海鸟离开”
17How, Atmosphere pressure, global climate changeC段最后一句C段首句说“南极洲并不总是很冷的”接着一步一步解释了南极洲气候变化形成的过程，最终katabatic wind为全球制造了可怕的风冷却效果
18Once, forgotten, insignificantA段第三句A段第二句中对Antarctic的形容是“an image of remoteness , hardship, bleakness and isolation”这是一幅遥远，艰难，阴郁，与世隔绝的景象
最后一句提到“one of a place removed from everyday reality, ······with no apparent value to anyone”是一个远离日常现实，对任何人没有明显价值的地方
19Antarctica’s size, climate changeB段最后一句B段最后一句中总结“Scientific research revealed- and continues to reveals that Antarctic’s great mass and low temperature exert a major influence on climate and ocean circulation,···· ”
20Western windC段第二句C段第二句“···create ···for the development of an ACC, that flowed from west to east under the influence of the prevailing westerly winds.”
21Southern Oscillation Index, AustraliaD段第四句D段第四句“···the temperature of the ocean may be a better predictor of rainfall than is······· Southern Oscillation Index”
本句有一个比较级说明海洋的温度和southern oscillation index都是用来预测rainfall的
22Heart, significance, climate and currentB段最后一句B段最后一句中的a major influence on climate and ocean circulation 正是 it is the heart and its significance to the global climate and current的同义句
23Reduce, economic lossesD段第五句，第六句D段中第五句提到“通过接收更为准确的预测，当地放牧人能够避免在降雨量不足的时期过度放牧”紧接着第六句说“Not only does this limit their losses·········”这会减少他们的损失
24Fresh ice, southern oceansF段第五句F段第五句中提到“Recent research has shown that as fresh sea ice forms, it is continuously stripped away······ ” 这表明下沉狂风katabatics会造成新的海冰形成
25Salt, density increaseF段第六句F段第六句详细指出“因为只有新鲜的水才能结冻成冰，残留的水变得越来越salty and dense, 下沉直到从continental shelf 剥落而沉下去”
26Sea ice, food sourceE段最后一句E段尾句表明“当海冰减少时，krill 不丰富时，baleen whales and flighted sea birds 会离开，在南半球之间迁徙”
Version 24101 主题 南极洲气候
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