Unit 8 Antarctica I. Assign the students to preview the text, and prepare at least two questions concerning Antarctica. II. Students are invited to tell in class what they know about Antarctica. III. Supply the supplementary information of Antarctica, including the natural environment, distinctive features, weather, and animal life etc. Antarctica, fifth largest of the earth's seven continents, located almost entirely south of latitude 66°30' south (the Antarctic Circle), and surrounding the South Pole. It is mostly circular in shape with a long arm—the Antarctic Peninsula—reaching out toward South America, and with two large indentations, the Ross and Weddell seas and their ice shelves. Its total area is about 14.2 million sq km (about 5.5 million sq mi) in summer. During the winter Antarctica doubles in size because of the large amount of sea ice that forms at its periphery. Antarctica has no native population. Its residents are scientific and support staffs who usually stay no more than a year at a time. The first person born in Antarctica was Emilio Palma, the son of the commander of Argentina's Esperanza Base, on January 7, 1978. Antarctica is more than 95 percent ice covered and contains about 70 percent of the world's fresh water. Because of its thick ice cover, it is the highest of all continents, with an average elevation of about 2300 m (about 7500 ft). The highest point on the continent is Vinson Massif (5140 m/16,864 ft); the lowest point appears to be the Bentley Subglacial Trench (2499 m/8200 ft below sea level) in West Antarctica. The Natural Environment Antarctica exists today in an ice age. Future economic development of the ice-covered landmass is highly unlikely. Resource exploitation on the continental shelf is possible, but certainly not for many years to come. Marine life in the waters surrounding Antarctica is currently being developed economically. This marine life includes whales and a tiny, shrimplike animal called krill. Physiographic Regions Antarctica consists of two main geologic areas. The larger of these, East Antarctica, is located mostly in the eastern hemisphere. It is probably a Precambrian shield covered by thousands of meters of ice. The Precambrian time was between 570 million and 4 billion years ago. West Antarctica, lying mostly within the western hemisphere, appears to be a continuation of the Andes of South America; glaciologists and geologists speculate that West Antarctica would become an island archipelago if the ice cover were removed. The two areas of Antarctica are separated by the Transantarctic Mountains, an uplift zone of mountains that extends across the entire continent, although portions are buried under the ice cover. Within these mountains are found many coal deposits and fossil remains related to the earlier tropical climate of Antarctica. Drainage and Water Resources The ice cover of Antarctica is continuously moving. Great ice rivers drain the interior of the continent and form the ice shelves. Coastal valleys drain parts of the mainland into the sea. Large tabular icebergs are formed as the edges of the ice shelves and glaciers calve off into the sea. Ice also extends over vast areas of the sea in the form of permanent floating ice shelves; the largest of these formations, the Ross Ice Shelf, is the size of the American state of Texas. The general isolation of Antarctica from the remainder of the world has allowed it to avoid the industrial pollution common to the other continents, so the snow and ice there are the purest in the world. Most scientific stations use snow melters to heat the ice and convert it to water for station use. Climate Antarctica is the coldest continent. Three basic climatic regions can be distinguished in Antarctica. The interior is characterized by extreme cold and light snowfall; the coastal areas are characterized by somewhat milder temperatures and much higher precipitation rates; and the Antarctic Peninsula is characterized by a warmer and wetter climate, with above-freezing temperatures common. The interior of Antarctica has almost continuous daylight during the southern hemisphere's summer and darkness during the southern hemisphere's winter. In coastal areas, which are farther north, long periods of sunshine occur during the summer, but sunrises and sunsets occur during much of the rest of the year. Vegetation The few plants that survive in Antarctica are restricted to the small ice-free areas. The continent has no trees, and vegetation is limited to about 350 species, mostly lichens, mosses, and algae. Lush beds of such vegetation exist in parts of the Antarctic Peninsula, and lichens have been discovered growing on isolated mountains within 475 km (295 mi) of the South Pole. Three species of flowering plants are also found on the Antarctic Peninsula. Animal Life No land-based vertebrate animals inhabit Antarctica. Invertebrates, especially mites and ticks, which can tolerate the lower temperatures, exist in the Antarctic Peninsula but are still considered rare. The surrounding ocean, however, abounds in living creatures. Large numbers of whales feed on the rich marine life, especially krill. Six species of seals (including the crabeater, elephant, and leopard) and about 12 species of birds live and breed in the Antarctic. The most prominent inhabitant of the Antarctic is the penguin. A flightless bird, it lives on the pack ice and in the oceans around Antarctica and breeds on the land or ice surfaces along the coast. Most typical are the Adélie and emperor penguins. Antarctica has no native population. Its residents are scientific and support staffs who usually stay no more than a year at a time. The first person born in Antarctica was Emilio Palma, the son of the commander of Argentina's Esperanza Base, on January 7, 1978. Antarctica is more than 95 percent ice covered and contains about 70 percent of the world's fresh water. Because of its thick ice cover, it is the highest of all continents, with an average elevation of about 2300 m (about 7500 ft). The highest point on the continent is Vinson Massif (5140 m/16,864 ft); the lowest point appears to be the Bentley Subglacial Trench (2499 m/8200 ft below sea level) in West Antarctica. This trench is covered with more than 3000 m (more than 9840 ft) of ice and snow. Lower points may exist under the ice, but they have not yet been discovered. Seven nations—Argentina, Australia, Chile, France, Great Britain, New Zealand, and Norway—have announced territorial claims to parts of Antarctica. Since the Antarctic Treaty of 1961, these claims have been held aside in the interests of international cooperation in scientific research. Mineral Resources Antarctica is thought to have large deposits of valuable mineral resources. Coal in commercially attractive deposits has been found, but no other minerals are known to exist in potentially useful amounts. Large deposits of oil and natural gas are believed to exist in Antarctica's continental shelf. Exploration Antarctica was not discovered until the early 1800s, largely because of its remoteness from the other continents. The ancient Greeks first theorized the existence of Antarctica when they realized that the southern hemisphere must have large continents to balance those in the northern hemisphere. Captain James Cook of Britain was the first explorer to cross the Antarctic Circle in the 1770s, but even though he circumnavigated Antarctica, he never sighted the continent. From deposits of rock in icebergs at sea, Cook realized that a southern continent existed, but it was not the lush, populated place some had expected. Early Exploration From 1819 to 1821, a Russian expedition under the naval officer and explorer Fabian von Bellingshausen circumnavigated Antarctica and discovered some offshore islands. Probably the first parties to sight the continent were that of the American sealer Nathaniel Palmer and that of the British naval officers William Smith and Edward Branfield, each of which sailed near the tip of the Antarctic Peninsula in 1820. The first known landing was made on February 7, 1821, by another American sealer, Captain John Davis. In 1823 the British whaler James Weddell discovered the sea that bears his name and penetrated to the southernmost point that any ship had then reached. Not until the 1840s, however, was Antarctica's status as a continent established. Three separate national expeditions—a French expedition under Jules Dumont d'Urville, a British expedition under Sir James Ross, and an American expedition under Captain Charles Wilkes—sailed along enough coastline to realize that the ice-covered land they saw was truly a continental land mass. From the late 1800s until the early 20th century, numerous expeditions visited Antarctica. With the encouragement of the International Geographical Congress, expeditions were sent out by several different nations, including Belgium, commanded by Adrien de Gerlache; Britain, commanded by Robert Scott and Carsten Borchgrevink; and Germany, commanded by Erich von Drygalski. Gerlache took his expedition, the first truly scientific Antarctic expedition, to the Pacific Ocean side of the Antarctic Peninsula, became caught in the ice, and spent the winter of 1897-1898 there. The Borchgrevink expedition landed men at Cape Adare in 1899 and became the first group to spend the winter on land. The Scott expedition of 1901-1904 used Ross Island in McMurdo Sound as a base and explored the Ross Ice Shelf and Victoria Land. From 1901 to 1903, Drygalski, who was a geophysicist, led an expedition to the Indian Ocean coast of Antarctica. Both Scott and Drygalski carried captive balloons and used them for aerial observation of the surface of Antarctica. Also in the Antarctic at this time were privately sponsored expeditions from Sweden under Otto Nordenskj?ld, from Scotland under William Bruce, and from France under Jean Charcot. Attaining the South Pole The search for the South Pole was the dominant theme in the next series of Antarctic expeditions. From 1907 to 1909, Sir Ernest Shackleton led a British expedition to within 156 km (97 mi) of the South Pole before turning back because of exhausted supplies. A second British expedition went into the field in 1910 under Robert Scott, as did a Norwegian expedition under Roald Amundsen. Using dogs to haul their sledges, Amundsen and a party of four reached the South Pole on December 14, 1911. Scott's party of five reached the pole on January 18, 1912, after hauling their sledges by hand over the roughest part of their route. All of Scott's party died on the return journey after the Norwegians successfully returned to their base. Shackleton returned to Antarctica in 1914 to attempt a crossing of the continent, but his ship, Endurance, became trapped in the ice and was crushed. Shackleton and his men made their way across ice floes to Elephant Island and were finally rescued in August 1916. Aerial Exploration In the 1920s, aviation came to Antarctica. The Australian Sir George Wilkins and the American C. B. Eielson became the first to fly an airplane over the continent when they explored the Antarctic Peninsula from the air in 1928. The American explorer Richard E. Byrd established a large camp—Little America—on the Ross Ice Shelf in early 1929 and in November flew to the South Pole. Byrd returned to Antarctica in 1934 with another expedition. Both expeditions included a scientific research staff. Other aviation expeditions included those of Lincoln Ellsworth, an American, who flew across the continent in 1935; the Norwegians, who conducted extensive exploration along the coastlines; the Germans, who sent an aviation expedition in 1938 and 1939; and the American U.S. Antarctic Service Expedition from 1939 to 1941. Following World War II (1939-1945), the United States sent the largest expedition ever to Antarctica. More than 4000 men participated in Operation Highjump with some 13 ships and more than 20 airplanes. Much of the coast was photographed by air for the preparation of maps. Recent Activities Long-term systematic exploration and scientific investigation of Antarctica began with the International Geophysical Year (IGY)—July 1, 1957, to December 31, 1958. Twelve nations established more than 60 scientific stations in Antarctica during the IGY and visited most parts of the continent. When the IGY came to a close, the 12 nations decided to continue their research during a year of International Geophysical Cooperation. Representatives of the 12 nations met in Washington, D.C., in 1959 to draft and sign the Antarctic Treaty, which dedicated the entire continent to peaceful scientific investigation; it came into effect in 1961, suspending all territorial claims. In 1991, 24 nations approved a protocol to the treaty that would ban oil and other mineral exploration for at least 50 years. Scientific Research Significant scientific research has been accomplished in Antarctica, including studies of glaciology, meteorology, geomagnetism, international weather control, seismology, and ionospheric physics. The nutrient-rich oceans that surround Antarctica are an important focus of research. Biologists have discovered that fish in Antarctic waters have an antifreeze component to their blood that allows them to live in subzero temperatures. Studies conducted on the life histories of penguins, seals, and krill (a potential world food source) have provided much new information on the ecology of these species. Internationally conducted studies have resulted in an improved understanding of krill reproduction and allowed scientists to improve their predictions of safe limits for krill harvesting. Geologists have now visited most exposed rock areas of the continent, increasing knowledge of the basic geologic structure and history of Antarctica. Glacial geologists studying the remains of past glaciers have discovered that Antarctica once contained much more ice than it now does. Fossil finds in Antarctica have included such achievements as the 1982 discovery of the first mammal remains found there and in 1986 of the first dinosaur fossil. Such fossils have by now provided a nearly complete sequential record of the breakup of the ancient supercontinent Gondwanaland. Volcanologists have extensively studied Mount Siple and the active volcano Mount Erebus. Geologists have collected thousands of meteorites (including a few rare moon fragments), which are especially valued for having been preserved in ice with little weathering or other deterioration. The ice cover itself has long been the subject of intense study. Glaciologists from several countries have employed modern methods of investigation such as radio glaciology to obtain information on the landscape under the ice cover, and to discover large lakes between the earth and the bottom of the ice. Satellites have been used to plot the slow movement of the ice surface. Ice cores drilled from Antarctica, including a complete core to the bottom of the Ross Ice Shelf and one through the ice of West Antarctica at Byrd Station, enabled French, Russian, and American scientists to trace changes in the continent's climate over a period of tens of thousands of years. French scientists have put radio transmitters on icebergs to plot their movement, and Australian and Saudi Arabian officials have considered the possibility of towing icebergs to arid regions for fresh water. Continuous weather records by meterologists have been taken for some 25 years and are providing an understanding of Antarctica's function in world climate. One such contribution has been the discovery, first noted by British scientists in 1985, that a so-called ozone hole develops each Antarctic spring in the stratosphere high above the continent and then more or less disappears by the end of the season. The meaning of this reduction in the ozone layer in the vicinity of the South Pole continues to be studied. It may be partly a natural phenomenon, but evidence indicates that the ozone loss is also related to the problem of the release of chlorofluorocarbons into the atmosphere. Physicians have made discoveries about the behavior of viruses in a cold, isolated environment. Psychological and sleep studies are frequently conducted during the winter, when Antarctica is isolated from the outside world. IV. Show part of the movie March of the Penguins.  V. Answer the students’ questions. For those difficult questions we do not have the answer, assign students to search for answers on the Internet or in the library. VI. Language points 1. outweigh: to be more significant than; exceed in value or importance The benefits outweigh the risks. The advantages of the plan outweigh drawbacks. My love for her outweighs everything. 2. hem: enclose / surrounded tightly The whole army was hemmed in by the enemy with no hope of escape. 3. populate: to supply with inhabitants, as by colonization; people; to live in; inhabit: creatures that populate the ocean depths. This side of the island is populated mainly by fishermen. Large number of snakes populate the woods. a thickly populated city 4. inclined: likely, tending The news makes me inclined to change my mind. I’m inclined to get tired easily. I incline to (take) the opposite point of view. 5. tempestuous: of, relating to, or resembling a tempest tempestuous gales 狂风 a tempestuous meeting of the council 6. precipitate: to cause (water vapor) to condense and fall from the air as rain, snow, sleet, or hail. Clouds usually precipitate as rain or snow. 7. disintegrate: (antonym: integrate) to break into pieces ancient wall disintegrated by time and weather Is society beginning to disintegrate? The extracted case was so old it just disintegrated when a worker picked it up. The rocks are disintegrated by frost and rain. integrate Many suggestions are needed to integrate the plan. 8. set eyes on ----- lay eyes on, see It was the most extraordinary thing that I had ever set eyes on. I had never set eyes on a book with such magnificent binding. set foot on/in---- go, visit Peter got measles so his mother doesn’t let him set foot out of the house. The invention of spacecraft has made it possible for man to set foot on the moon, and other planets too. 9. In these conditions, it was possible to stand for no more than a few seconds, and then only by leaning forward at an angle of 45(. Under such conditions, a person could only stand for a few seconds, and that was by leaning forward to form an angle of 45( with the ground. 10. Small wonder that ……, the southernmost continent remained inviolate. Small wonder that … = No wonder that…. It is not surprising that although man did not hesitate to explore and take possession of most of the earth in the 18th and early 19th centuries, the continent in the far south was left untouched.. Quiz 8 (Unit 8&9) Name ______________ Score ______________ I. Explain the following words, phrases and sentences in your own words. 1. outweigh: 2. tempestuous: 3. obscure (v.): 4. judicious: 5. fat hammock (unit 9): 6. lust: 7. non-stop: 8. disintegrate: 9. strangle out: 10. or married him for that matter: 11. injurious: 12. …their finger-tips burned a little… 13. the nerves of the town were pulsing and vibrating with the news. 14. The essence of pearl mixed with essence of men and a curious dark residue was precipitated. II. Match the following phrases according to the texts. III. Write out the adjectives of the following nouns. 1. loose inviolate 1. winter  2．remain feeling of rage and misery 2. integration  3．black granules 3. spontaneity  4．poison feature 4. sympathy  5．swelling sacs 5. metaphor  6．glittering landmasses 6. essence  7．populated distillate 7. imagine  8．distinctive eyes   IV. Make a sentence with each of the following phrases, with no less than 12 words. let alone set eyes (foot) on when it was made plain every other … 5. hemmed in V. Translate the following into English. 成都举行的一年一度的美食节吸引了来自全世界的各类人士。 2．有一些确凿的证据表明外星人造访过地球，这些不明飞行物对地球人来说一直是一个难解之迷。 3．我总觉得我们的总裁目光远大、足智多谋；他带领公司员工利用甘甜清新的山泉制成矿泉水，提供人体健康所必需的矿物质。