VOA慢速英语2009-EXPLORATIONS - Antarctica: A Scientific Labo（在线收听）

VOICE ONE:

I'm Bob Doughty.

VOICE TWO:

And I'm Faith Lapidus with EXPLORATIONS in VOA Special English. Today we travel south to one of the coldest, windiest and least populated places in the world, Antarctica. The word "Antarctica" comes from a Greek root meaning "opposite to the north."
　
The Leverett Glacier on Antarctica is about 100 kilometers long

This huge continent on the Earth's South Pole covers about fourteen million square kilometers. About ninety-eight percent of this area is covered in ice. Join us as we explore the history of Antarctica and its environmental and scientific importance.

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Every year, scientists from over twenty-seven countries carry out research in a place that is like no other in the world. Scientists from many areas of study come to Antarctica. They include biologists, astronomers, physicists and geologists. There are always exciting discoveries being made in this huge natural laboratory.

For example, scientists recently discovered a group of small organisms that appear to have lived for millions of years under the ice. The water under the ice is very salty and contains many kinds of minerals including iron. The bacteria use these minerals to survive. Jill Mikucki led the team of scientists who explored an area under an ice formation called Taylor Glacier.

JILL MIKUCKI: "We have a lot to learn from the microbes that survive in these kinds of environments and have adapted to these cold, low-energy systems. They're very efficient."

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Researchers lowering the underwater robot into Lake Bonney

Not far from Taylor Glacier, researchers for the American space Agency are using the icy Lake Bonney to test an underwater robot vehicle. The vehicle is helping scientists to see for the first time huge areas underneath the lake that were otherwise impossible to explore. Developing this kind of vehicle could be useful for future space operations. Scientists hope this vehicle could permit them to one day explore the icy oceans on Jupiter's moon Europa.

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One of the most important subjects studied on Antarctica is climate change. Scientists say the thinning ozone layer over the South Pole makes climate change take place more quickly than in other areas of the world.

Yves Frenot is deputy director of the French Polar Institute. He says that in the Antarctic Peninsula, scientists estimate that climate change has caused temperatures to increase by two or three degrees Celsius over the past fifty years. He says this is a very huge increase compared to what has happened in the past.

Signs of climate change include an increase in rain when there used to be only snow, new plant life, and melting ice sheets. The melting ice resulting from climate change would affect coastal areas around the world. But scientists disagree about how much sea levels could rise if Antarctica's ice sheets continue to melt.

One group of researchers published its findings in Science magazine last month. Jonathan Bamber of the Bristol Glaciology Center in England led the study. The team predicted sea levels would rise by about three meters. This is three meters less than other studies have estimated. Most scientists agree that climate change is a serious problem that requires the attention of people and governments around the world.

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Captain James Cook

There is no official agreement about who discovered Antarctica. Since ancient times, thinkers including the Greek astronomer Ptolemy believed in the existence of a huge continent on the South Pole. They gave a name to this mysterious continent: Terra Australis Incognita, or the "Unknown Southern Land."

The English explorer James Cook came looking for this undiscovered continent in the seventeen seventies. But he was looking for a much larger continent. On his third trip, he and his team circled Antarctica. His boat crossed the Antarctic Circle in three places, but he still failed to sight land. At the time, this was the furthest south anyone had ever traveled.

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Around eighteen twenty, crew members on three different ships claimed to have sighted Antarctica. These were the American sailor Nathaniel Palmer, the Russian Captain Fabian Bellingshausen and the British Captain Edward Bransfield. The race by countries to explore Antarctica had begun.

Looking at a modern day map of Antarctica gives clues about its first explorers. In eighteen thirty-nine the American Naval officer Charles Wilkes led an expedition to the continent. He mapped over two thousand kilometers of the continent's coastline. His efforts helped prove that Antarctica was in fact a continent. The Wilkes Land area is named for him.

In eighteen forty-one, the British navy officer James Ross discovered areas now called the Ross Sea and Ross Ice Shelf. Other famous twentieth century explorers of Antarctica included Ernest Shackleton, Roald Amundsen, and Richard Evelyn Byrd.

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It might seem surprising that a freezing continent with no native human population would be defined by a legal agreement signed by over forty countries. Antarctica is governed by a collection of agreements known as the Antarctic Treaty System.

The main agreement of the system, the Antarctic Treaty, was signed by twelve countries in nineteen fifty-nine. It went into effect two years later.

Seven of the twelve countries claim Antarctic territory, although the United States does not recognize the claims. These seven are Argentina, Australia, Chile, France, New Zealand, Norway and the United Kingdom. The other five countries that signed the treaty were Belgium, Japan, South Africa, the Soviet Union and the United States.

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The main goal of the Antarctic Treaty is to support scientific research and the exchange of information. The treaty also guarantees that Antarctica will continue to be used for peaceful purposes and will not become the object of international dispute. The treaty bans nuclear explosions, nuclear waste, and any military activity such as weapons testing. The treaty also does not recognize, dispute or establish claims of territorial ownership by a country.

Since nineteen fifty-nine, thirty-five other countries have joined the treaty. Some countries are voting members, while others are non-voting members.

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Sharing Antarctica for science makes sense. Researchers have found that working together in the severe environment saves them time and money. Antoine Guichard agrees. He is part of the National Antarctic Programs.

ANTOINCE GUICHARD: "It is so expensive that if you don't help each other, usually you just don't manage. And now with Antarctic science being really a global science and part of understanding how the world works, it is becoming really vital that everybody works together."

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The treaty also calls for countries to gather for Antarctic Treaty Consultative Meetings. The meetings used to be held about once every two years. Now, the group meets yearly. In April, the group met in Baltimore, Maryland. About four hundred diplomats, scientists, and Antarctic program supervisors from forty-seven countries met. They discussed protecting the environment, supporting science, and controlling travel to Antarctica.

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Travel was an important subject at the last Antarctic Treaty Consultative Meeting because the continent has become a popular place for adventurous visitors.

Last year, about forty-five thousand travelers visited the continent. The number of visitors has increased by ten times in the past fifteen years. Large ships that travel to the area sometimes have accidents resulting in leaks of gasoline or oil. These chemicals can have a very damaging effect on krill, sea creatures that are an important part of the food chain in Antarctic waters.

Treaty members agreed to approve rules banning ships carrying more than five hundred travelers. And, the ships cannot bring on land more than one hundred passengers at a time. Rules would also call for new requirements for lifeboats on these ships.

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But visitors are not the only concern. More and more scientific research stations are also affecting the environment. There are about sixty research stations on the continent. Jose Retamales is the director of the Chilean Antarctic Institute.

JOSE RETAMALES: "Half the buildings you have seen, they were not there five years ago. The Chinese station, the Korean Station, they're new buildings. I don't think we should have so many stations in Antarctica."

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Research stations are taking steps to protect the environment. For example, they are reusing materials and heating buildings in a more environmentally friendly way. The scientists on Antarctica know better than anyone about the effects of pollution and human behavior on this important treasure of a continent.

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VOICE ONE:

This program was written and produced by Dana Demange. I'm Bob Doughty.

VOICE TWO:

And I'm Faith Lapidus. You can find transcripts, MP3s and podcasts of our reports at voaspecialenglish.com. Join us again next week for EXPLORATIONS in VOA Special English.