Antarctica

Welcome dear students! Today we are going to learn about Antarctica from Class 7 Social_Science. This chapter introduces us to the study of location, extent and physical setting of Antarctica, its physical features, natural vegetation, animal life, exploration, Antarctic Treaty and important research stations. Our learning goals are clear. You will know the location, extent and physical setting of Antarctica. You will understand the physical features, land and water bodies of the continent. You will understand the natural vegetation and animal life of Antarctica. Finally, you will know about the exploration, treaty and important research stations of the continent.

Let us begin with Location, Extent and Physical Setting. Location wise, Antarctica is the continent which surrounds the South Pole. Most of the continent lies within the Antarctic Circle or 66°30' South latitude. The uniqueness of the continent is that it is positioned opposite to the Arctic Ocean in the North Pole. In terms of extent, Antarctica is the 5th largest continent with a total area of 14.2 million km2. It is larger than India and China and is 1.5 times larger in area than the USA.

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Now, let us look at the Physical Setting. The continent of Antarctica is surrounded by water bodies. It is often called the Southern Ocean or Antarctic Ocean. It is not a separate water body. Instead, it is formed by the meeting of the Indian Ocean and the Pacific Ocean. Capehorn, the southern most part of Latin America, is the nearest land to this continent. It is at a distance of 990 km. Antarctica is bound by the Indian ocean on the East, the Pacific ocean on the West and the Atlantic ocean on the Northwest. If you were to visualize a map of Antarctica, you would see it surrounded by these 3 oceans. The map shows various longitudes and latitudes, and highlights several important research stations. You would see Indian stations like Dakshina Gangotri and Maitri, Japanese station Asuka, Russian stations Molodezhnaya, Russkaya, Mirnyy, Oasis and Vostok, Australian stations Mawson, Amery, Davis and Casey, American station McMurdo, New Zealand station Vada, French station Charrot, and the American South Pole station Amundsen-Scott. The map also marks major geographical features like Coats Land, Dronning Maud Land, Graham Land, the Antarctic Peninsula, Greater Antarctica, American High Land, Wilkes Land, Little America, Commonwealth Bay, and Mac Robertson Land. Prominent peaks marked include Mt. Tolchin, Mt. Vinson Massif, Mt. Wright Peak, Mt. Seelig, Mt. Sidley, Mt. Siple, Mt. Kikpatrick, Mt. Markham, and Mt. Erebus.

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Moving on to Physical Features. About 98% of Antarctica is covered with ice and snow. Most of the relief features of the continent are covered by sheets of ice. High mountain peaks and a few plateaus are the only visible land surfaces. The layer of ice which is approximately 2300 m thick, makes it look white. So, Antarctica is also called the White Continent or the Snow Desert or the Cold Desert as it has an extremely cold climate. Under the ice, Antarctica has the relief features such as mountains, plateaus, valleys and gorges. Antarctica is the highest continent at an average elevation of 2300m above sea level. The trans-antarctic mountain range divides Antarctica into 2 major physical divisions. These are East Antarctica and West Antarctica. East Antarctica faces the South Atlantic Ocean and the Indian ocean. It covers more than half of the continent and is called the greater Antarctica. Along its coast, there are mountains, valleys and glaciers. The central part of the region is a plateau where the South Pole is located.

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West Antarctica is towards the Pacific Ocean. Much of its area lies below sea level. The peninsular region of Antarctica is a mountainous S shaped fringe of land, that points towards South America. There are several islands near it. In addition, it also has mountain peaks and volcanoes. Vinson Massif, the highest peak in Antarctica at 5140 m, is located in the Ellsworth Mountains. Mt. Erebus, Antarctica's most active volcano is on Ross Island. Prince Charles mountains is another prominent mountain group. 2 large gulfs cut into Antarctica on the opposite ends of the trans Antarctic mountain range, namely the Ross Sea and the Weddell Sea.

Let us now explore the Vegetation and Animal Wealth. As mentioned earlier, the continent of Antarctica is covered by thick sheets of ice. The climate of the continent is extremely cold and hostile. It has 6 months of sunshine and 6 months of darkness. It is very difficult for life to sustain. Very limited plant life can survive here. It mainly consists of mosses, algae and lichens growing on the exposed part of rocks. Only very few animals which can survive the adverse climate, live here. But a variety of animal life can be found in the surrounding water bodies. For example, the krills, penguins, whales, seals and a variety of seabirds.

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The krill, a small fish resembling shrimps and prawns, is found in abundance. They usually swim in large groups and survive on planktons. The small organisms are the main source of food for large sea animals and fish. Penguins are abundantly found along the coast of the sea. They are large flightless birds. Adelie, Emperor and Chinstrap are the chief species of penguins found here. Adelie penguins are the first to welcome the ships onto this ice-packed continent. In the nearby islands and the sea coast, a variety of seals are found in abundance. 6 different species of seals have been identified. Continuous hunting has endangered the life of these seals. Please note 2 important facts. The nest built by penguins, in the hollows of rocks, for their reproduction is called Rookery. Vostok is a place in Antarctica, near the South Pole which has recorded the lowest temperature of -89°C in the world.

Now, let us travel through history with the Antarctic Expedition and the Antarctic Treaty. The expedition to the continent of Antarctica which began in the 18th century has continued even to this day. Many sea voyagers made adventurous efforts to explore the continent. Charles Wills, head of the US Navy, discovered the continent of Antarctica. Another voyager James Clark Ross of Great Britain, discovered the Ross Sea, named after him, in 1841. Robert Falcon Scott of England succeeded in crossing this sea. The explorers generally enter this continent during the end of the summer seasons and prepare their winter bases. A detailed exploration of the continent commenced in the beginning of the 20th century. England's Shackleton reached the South Pole in 1909. Roald Amundsen, a Norwegian explorer reached the South pole in 1911. In 1912, Scott from the USA heading another expedition arrived at the pole just a month later but died on his return journey. His diary entries proved useful for further scientific exploration on the continent. Richard E Byrd, an Admiral in the American Navy was the first to reach the South Pole in 1929, by plane. Later several countries of the world came forward to study the continent of Antarctica.

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This leads us to the Antarctic Treaty. This is an agreement between the countries to keep Antarctica as a place just for scientific research. It was, therefore, called the Continent of Science. The treaty was signed in Washington DC on 1st December 1959 by 12 nations and it came into force on 23rd June 1961. The treaty applies to the region South of 60° latitude. The member nations are Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, UK and the USA. The objectives of the Treaty are very clear. According to the treaty, this continent has to be used only for scientific research purposes. Testing of nuclear weapons is prohibited here. No country can claim the ownership of land and water. Polluting the environment is prohibited here. Explorers to this continent are not allowed to bring any exotic living species. Whale hunting is also banned. One can openly exchange scientific information. It is also agreed upon to preserve and conserve the natural resources of the continent. To sum up, this continent has to be used only for peaceful purposes.

Let us look at Research on the Snow Desert. About 90% of the world's fresh water is conserved in the form of ice in Antarctica.

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Now, we will learn about Important Research Stations. In many ways, the continent of Antarctica is reserved for global scientific research and has been of great interest. Several aspects of the continent, such as its origin, topography, climatic condition, biological ecosystem, biodiversity and conservation, environmental pollution and measures to overcome it, waste disposal and management, accidents due to oil spills and strict measures to be followed to solve the issue, are some of the research topics. In order to conduct research in these areas, more than about 30 nations of the world have established their research stations here. India has also established its own research station in Antarctica. Under the leadership of Dr. S. Z Qasim, a team of scientists set sail from Goa, on 6 December 1981. The ship that carried these scientists, the Polar Circle, reached the continent of Antarctica on 9th January 1982. The first research centre established by the Indian scientists was called Dakshina Gangotri. It was built in 1983 and was named in 1989. Presently, there are no men here and it is only used for storage purposes. After the first successful expedition to the continent of Antarctica, the Indian Research teams have visited it around 50 times. Maitri is the second research station. It was set up on the Schirmacher Oasis in 1988-89. It is all-weather proof and can accommodate 26 people. 255m from this station, India has built a freshwater lake known as Priyadarshini. The Maitri Research Centre conducts research on Geology, Geography and Medicine. India has proposed to build another research center Bharathi. It intends to do research on Oceanography. Necessary survey has already been completed.

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Let us quickly review the New Terms from this chapter. They are White Continent, Cold Continent, Vinson Massif, Erebus, Moss, Penguin, Whale, Seal, Shrimp, Adelie, Chinstrap, Krill, Dakshina Gangotri, Maitri, Bharathi.

Now, it is time to solve the Exercises together. I will answer each one completely. Part I, Fill in the blanks with a suitable word. 1. The land mass nearest to the continent of Antarctica is Cape Horn. 2. The one who discovered the continent of Antarctica was Charles Wills. 3. The person who discovered the South Pole was Roald Amundsen. 4. The first research station established by the Indian team in Antarctica was Dakshina Gangotri.

Part II, Answer the following questions. 5. Mention the location and extent of Antarctica. Answer: Antarctica is located surrounding the South Pole, with most of it lying within the Antarctic Circle or 66°30' South latitude. It is positioned opposite to the Arctic Ocean. In terms of extent, it is the 5th largest continent with a total area of 14.2 million km2. It is larger than India and China, and 1.5 times larger than the USA.

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6. Explain the physical settings of Antarctica. Answer: Antarctica is surrounded by water bodies often called the Southern Ocean or Antarctic Ocean, formed by the meeting of the Indian and Pacific Oceans. It is bound by the Indian Ocean on the East, the Pacific Ocean on the West, and the Atlantic Ocean on the Northwest. The nearest land is Cape Horn, located 990 km away.

7. Mention the important mountains and peaks of Antarctica. Answer: The important mountains and peaks include the Trans-Antarctic mountain range, Vinson Massif which is the highest peak at 5140 m located in the Ellsworth Mountains, Mt. Erebus which is the most active volcano on Ross Island, and the Prince Charles mountains.

8. Name the plants and animals of Antarctica. Answer: The plants mainly consist of mosses, algae and lichens. The animals include krills, penguins such as Adelie, Emperor and Chinstrap species, whales, 6 different species of seals, and a variety of seabirds.

9. Mention the Indian Research Centres in Antarctica. Answer: The Indian Research Centres in Antarctica are Dakshina Gangotri, Maitri, and the proposed Bharathi station.

Finally, let us look at the Activities. Activity 1 asks you to prepare a list of the Research Centres of different countries in Antarctica and collect their photographs. Activity 2 asks you to make a list of the variety of plants and animals in Antarctica and collect their pictures. I encourage you to complete these activities in your notebooks to strengthen your understanding.

Thank you for listening! Keep revising and practicing. Goodbye! [CHAPTER_COMPLETE]