Exploring Continents Africa Australia And Antarctica
Class 8 | Social Science — Geography | Unit 7
Class 8 Unit 7 Geography
Unit 7 Exploring Continents Africa, Australia and Antarctica
Learning Objectives
1. To study the Geographical location of the continents of Africa, Australia and Antarctica.
2. To learn the physical setting, climate and drainage of the continents.
3. To understand the nature of the flora and fauna of the continents.
4.To identify the major resources and economic activities.
5.To develop the mapping skill.
Introduction
A teacher handling class 8 entered the classroom and asked the students what they were talking about. The class monitor told the teacher that the students were talking about the ODI match between Australia and South Africa. The teacher said to the students, "Well today we will learn many things about them in this lesson".
Africa
Location and size
Africa is the second largest and second most populous continent after Asia. It stretches from 37 degree 21 minitees North latitude to 34 degree 51 minitees South latitude and from 17 degree 33 minitees West longitude to 51 degree 27 minitees East longitude. It spreads over an area of about 30.36 million square kilometres (20.2 percentage of the world's land area). The equator passes through the middle of Africa and cuts into two equal halves. It is the only continent through which the major latitudes such as Tropic of Cancer, Equator and Tropic of Capricorn pass. Its north-south extent is 7623 km and east-west extent is 7260 km. The Prime Meridian passes near Accra the capital of Ghana in the West of this continent. Africa is located in all the four hemispheres. The great explorers David Living Stone and H.M. Stanley were the first to explore the interior parts of this continent. The sources reveal that the early human ancestors have lived in Africa for more than 5 million years. Africa is nicknamed as the "Mother Continent" as it was the oldest inhabited continent on Earth. The diverse geographical condition of the Continent is the main reason for heterogeneous culture and home of several ethnic groups in Africa.
Do You Know?
Africa is called a Dark Continent. In the beginning the interior of Africa was largely unknown to them. The European explorer Henry M. Stanley was the first to use the term the "Dark Continent" (1878).
The continent of Africa consists of 54 countries. On the basis of their geographical location, the countries are grouped as a) West Africa b) North Africa c) Central Africa d) Eastern Africa e) Southern Africa.
Do You Know?
The north-western African countries of Morocco, Algeria, Libya, Mauritania and Tunisia are collectively called 'Maghreb' which means west in Arabic language.
Physiographic Divisions
Africa consists of mixture of land forms such as mountains, plateaus and plains. The following are the 8 major physical divisions of Africa. Madagaskar is the major island of Africa.
1. Sahara
The world-famous Sahara Desert is located in the northern part of Africa. It is one of the largest hot deserts in the world. It has an area of 9.2 million sq km. The Sahara is bordered by the Atlantic Ocean in the west, the Red Sea in the east, the Mediterranean Sea in the north and Sahel in the south. This desert covers the areas of 11 countries: Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia. It consists of many topographical features such as mountains, plateaus, ergs, oases, sand- and gravel-covered plains, salt flats, basins and depressions. Mount Koussi, an extinct volcano in Chad, is the highest point in the Sahara with 3,445 m and the Qattara Depression in Egypt is the Sahara's deepest point (133 m below sea level). Nile and Niger rivers run through the desert. Atlas Mountain lies in the north- west of Africa. It is a young fold mountain. It separates the Mediterranean sea and Atlantic ocean. The highest point is Mount Toubkal (4167m).
2. Sahel
Sahel means border or margin. Sahel is a semi-arid tropical Savanna region lies between the Sahara Desert in the north and Savanna grassland in the south. It stretches east-west for a distance of 4000 km and covers an area of 3.0 million sq km. It is largely a semi-arid belt of barren, sandy and rocky land. This region marks the physical and cultural transition between the more fertile tropical regions in the south and desert in the north.
3. Savanna
Tropical dry grasslands with scattered trees are known as 'Savanna'. It is located near the equator and covers almost half of the area of Africa. This grassland is found in the regions just north and south of the rainforests that lie along the equator. Trees are the main features of the landscape in some parts of the savanna, while tall grass covers the other areas. Animals of many species graze in this zone. The Serengeti Plain is one of the largest plains in Savanna. This is called the 'Open Air Zoo'.
4. The Great Rift Valley and the Great Lakes of Africa
A rift valley is a large crack in the earth's surface formed by the shifting of tectonic plates. One of the major geographical and geological features of Africa is the Great Rift Valley. It stretches from northern Syria in Asia to central Mozambique in Africa for a distance of 6400 kilometers. It runs through the eastern Africa and contains many lakes.
ActivityFind out-the Great Rift Valley and the lakes connected with it from the atlas and mention them on the map of Africa.
The African Great Lakes are a series of lakes found in the rift valley. The water in the Great lakes of Africa constitutes about 25% of the planet's unfrozen surface fresh water. There are seven major lakes in this region. Lake Victoria of this region is the largest fresh water body in Africa and second largest in the world, next to Lake Superior in USA. It is the source of river Nile. The other lake in the valley is Tanganyika which is the longest and deepest fresh water lake in the world. Lake Albert, Lake Edward, Lake Kivu, Lake Malawi, and Lake Turkana are the other important lakes in Africa.
Do You Know?
The glaciers on the top of Kilimanjaro have been disappearing since 20th centuriers
5. East African Highlands
Most African mountains are found in these high lands. It stretches from Ethiopia to Cape of Good Hope. Mt. Kilimanjaro (5895m) is the highest peak located in these highlands. Mt. Kenya and Mt. Ruwenzori are the major mountains located in these high lands. This region is sparsely populated and covered with rich grassland, forests, streams and waterfalls of natural scenic beauty. It enjoys misty mornings and fresh mountain breezes which attract large number of tourists from other parts of the World.
6. Swahili Coast
Swahili coast is located along the shores of East Africa. It stretches about 1,610 kilometers along the Indian Ocean from Somalia to Mozambique. It was a region where the Africans and Arabs mixed to create a unique culture referred to as Swahili Culture. People of this coast are also called 'Swahili'.
7. The Congo Basin or Zaire Basin
Congo Basin lies on the both sides of the equator in west Central Africa. It comprises an area of more than 3.4 million square kilometres and covered with dense evergreen forest. It provides food, shelter, medicine, water, and materials for over 7.5 million people. It is the world's second largest river basin next to Amazon.
8. Southern Africa
Most part of the Southern Africa is a plateau region. Drakensberg Mountain is found in the eastern portion of the escarpment. It extends from north east to south west for 1125 km. Its highest peak is Thabana Ntlenyana (3482m). This region is covered with grasslands known as 'Veld'. Kalahari Desert lies in the south and Namib Desert is along the south -west shore of Africa. Kalahari Desert in this region is not actually a desert, but a bushy scrubland situated between the Orange and Zambezi Rivers.
Drainage of Africa
1. River Nile
The Nile is the longest river in the world with a length of 6650 km. It has two main tributaries. They are the White Nile, which originates from Burundi, and the Blue Nile, which originates from Ethiopia. These two join and form the Nile River at Khartoum, in Sudan. It flows towards northward and drains into the Mediterranean-sea. Nile is known as the "Father of African Rivers".
Do You Know?
The country Egypt is called the "Gift of the Nile" as it is the lifeline of the Egypt. Without Nile the Egypt would have been a desert.
ActivityOn the outline map of Africa draw the courses of main rivers and name them
2. River Congo or Zaire
Congo is the second largest river of Africa after Nile. Its length is about 4700km. Congo rises in the highlands of North Eastern Zambia between lakes Tanganyika and Nyasa. It flows through West Central Africa and drains into the Atlantic Ocean.
3. River Niger
Niger is one of the major rivers in West Africa and rises from the highlands of Guinea. It flows for about 4184 km and finally drains into the Gulf of Guinea on the Atlantic Ocean.
4. River Zambezi
The Zambezi River is the fourth longest in Africa. It rises in the north western Zambia. It is about 2574 km long and drains into the Indian ocean. The world famous waterfall 'Victoria' is formed by this river at the height of 108 meters. It is called the Southern Africa's "River of Life". River Limpopo and river Orange are the other important rivers of Africa.
Climate
Africa is divided into six major climatic zones. They are:
1. Arid and semi-arid climate: Northern Africa and Southern Africa have this climate. Rainfall is scanty in this part.
2. Tropical savanna climate: It is found from 10 degree to 20 degree latitudes on either side of the equator. It is a tropical wet and dry climate.
3. Equatorial climate: It is found in the equatorial region covering the Congo River basin and east African highlands. Temperature and rainfall are high all the year round in this region
4. Temperate climate: It prevails in southern tip of South Africa. Since this part is located on the coast, the climate of this region is equable.
5. Mediterranean climate: It is found in the north-western and south western tips of Africa. These regions get rainfall in winters while in summers it is hot and dry.
6. Tropical Monsoon climate: It is found in the eastern shore of Africa. Summers are hot with monsoon winds bringing good rainfall while winters are cool and dry.
FACT
Tropical deserts are located between 20° and 30° north and south of the equator on the western margin of the continents. The deserts lie in the belt of the trade winds which blow from northeast in the northern hemisphere and southeast in the southern hemisphere. Therefore, the general direction of the trade winds is from east to west. These winds shed their moisture on the eastern margins of the continents and by the time they reach the west, they lose their moisture.
Flora and Fauna
African vegetation develops in direct response to the interacting effects of rainfall, temperature, topography and type of soil. Forests cover about 20% of the total land area of the continent. The flora and fauna currently found in Africa are descended from plant and animal species that were present in the continent when it was separated from other land masses during the break up of Gondwanaland. Baobab, Fever tree and Sausage are the major trees of Africa. There are over one million species of animals in Africa, including both the heaviest (elephants) and the tallest (giraffes) land animals on the earth. White Rhinoceros, Western Green Mamba, Zebra, African Elephants, chimpanzee, gorilla, Wildebeest, Hippopotamus, and Giraffe are the major animals of Africa. Bonobo, Wild Dogs, hyena and Lemur are the typical animals of Africa.
Do You Know?
A hot and dry dusty local wind blowing from the Sahara desert to Guinea coast is called 'Harmattan'.
• A hot local wind blowing from Sahara to Mediterranean Sea is called 'Sirocco'.
• Tropical rain forest is called the 'Jewel of the earth' and the World's largest pharmacy.
Agriculture
Agriculture is a major economic activity of the African continent. Wheat is grown in the temperate grasslands, Mediterranean region and the Nile valley. Rice is cultivated in Guinea coast, Mozambique, Madagascar and Nile valley. Maize and millets are grown all over the plateau regions. Cotton is the chief cash crop of Africa. Egypt and Sudan cultivate the best quality long staple cotton in the world. Coffee is grown in Ethiopia. Ghana is the chief producer of cocoa. Oil palm is cultivated in West African countries. Sugarcane, rubber, sisal and tobacco are the other major crops and are mostly grown in East African countries.
Minerals
Africa is rich in few mineral deposits. The region at the south of Sahara and the plateaus of Africa are the major mineral regions of the continent. Diamonds are found in South Africa, Congo, Botswana, Sierra Leone and Angola. Kimberly in South Africa is the important producer of diamond. Angola, Nigeria, Gabon and Congo have more oil reserves. Gold is found in South Africa, Namibia, West Africa and Ghana. Chromium, cobalt, copper, iron ore, manganese. Zinc and nickel are scattered across the continent.
Transport
Transports play an important role in the economic development of a region. The physical features and slow economic growth hinder the transport system in many African countries.
1. Land ways Roadways and Railways in Africa are poorly developed due to the presence of many barriers. It is very difficult to lay the roads and rails across the deserts and the dense forests. South Africa, Kenya, Egypt, Libya, Morocco and Nigeria have roadways and railways to some extent.
2. Waterways Africa has trade routes between Asia and Australia in the east, Europe in the north and America in the west. The major sea ports of Africa are Durban, Dar es Salaam and Mogadishu on the Indian Ocean, Port Said, and Alexandria, on the Mediterranean Sea, Cape Town, Algiers and Abidjan on the Atlantic Ocean.
3. Airways They connect the capital cities of Africa and the other parts of the world. The major international airports of the continent are Cairo, Johannesburg, Nairobi, Dakar, Addis- Ababa, Casablanca, Durban, Douala and Logos.
Population
Africa is the world's second most populous continent. The United Nations estimated the population of Africa as 131 crores in 2019. The population is unevenly distributed due to physical barriers. The population density in Africa is 45 persons per sq km. 41% of the population lives in urban and 59% in rural areas. Nile delta region and South Africa are the densely populated regions of Africa. Nigeria is the most populous country of Africa followed by Ethiopia.
Do You Know?
The major tribes of the world are called the first indigenous people. These people have a strong sense of their own identity as unique with their own lands, languages and cultures. Afar, Fatwa, Bushmen, Dinka, Masai, Pygmies, Zulu, Tswan, and Efe are the major tribes of Africa.
Australia
Australia was the last of all the continents to be discovered, and this was due to its remoteness. Australia is the largest island and smallest continent in the world. It is the only continent that completely occupies a single country. It has diverse in unique flora and fauna. Now let us explore the continent.
Do You Know?
Australia was discovered by Captain James Cook, an English Seaman in 1770.
Location and Size:
Australia extends from 10 degree 4' south to 39 degree 08' south latitudes and 113 degree 09' east to 153 degree 39' east longitudes. The Tropic of Capricorn cuts the continent almost into two equal halves. Area of the country is about 7.68 million sq kilometer.
Political Divisions
There are six states and two Union Territory in Australia 1) New South Wales 2) Queensland 3) South Australia 4) Tasmania 5) Victoria 6) Western Australia 7) Northern Territory8) Capital Territory (Canberra). Each state has its own state constitution. Canberra is the capital of Australia. Sydney, Brisbane, Adelaide, Hobart, Melbourne, Perth and Darwin are the other important cities of Australia. Australia has 8,222 islands. Rottnest Island, Magnetic Island, Fitzroy Island, Fraser Island, Phillip Island, Lord Howe Island, Kangaroo Island and Whitsunday Islands are the major islands.
Physical Divisions
It is the continent with very low irregularities in topography. Based on the nature of topography, it can be divided into three physical divisions namely:
1. The Great Western Plateau
2. The Central Low lands
3. The Eastern High lands
The Great Western Plateau
The Western Plateau is Australia's largest physical division. It incorporates one third of the continent. Its area is about 2,700,000 square kilometers. It is an arid land covering large part of Western Australia, Southern Australia and the Northern Territory. The flat surface is covered by sandy and rocky features. Ayers rock or Uluru is the largest monolith rock in the world. It is found in the central part of this arid region. It is 863 meters high above the sea level. It is one of the natural wonders of Australia. The pointed limestone pillars called Pinnacles are common in this region. The McDonnell and Musgrave ranges are located in this plateau the treeless region of Nullarbor Plain is located in the southern part of this plateau. The Great Victoria Desert is the largest desert in Australia located in Western Australia and South Australia.
The Central Low lands
The central lowlands extend from the Gulf of Carpentaria in the north to Indian Ocean in the south. In the centre of these low lands lies the large inland drainage basin of Australia. Lake Eyre is the largest salt lake lies in this region. The Murray–Darling River system lies in the south-eastern part of the central lowlands. Beneath the central lowlands, huge artesian basins are found.
The Eastern Highlands
The eastern highlands extend for about 3860 km along the eastern edge of Australia. It stretches from Cape York in the north to Tasmania in the south. They are also known as the 'Great Dividing Range' as it separates the west and east flowing rivers. Australian Alps mountain range is the highest mountain range of Australia. It is covered with ice. The highest peak of this range is Mt. Kosciuszko (2230m) and is located in the New South Wales.
Australia has two important natural features that have enriched the country. They are 1. The Artesian Basin 2. The Great Barrier Reef.
The Great Artesian Basin
The Artesian Basins are regions on the earth's surface where water gushes out like a fountain. The great artesian basin in Australia is the largest and deepest basin in the world. The artesian basin is located in the west of the Great Dividing Range. It is found in the arid and semi-arid parts of Queensland, New South Wales, South Australia and Northern Territory. It extends for 1.7 million square km and it is also a major source of water in this region.
Great Barrier Reef
Great Barrier Reef is located in the North East of Australia along the East Coast of Queensland in the Pacific Ocean. It is formed by the tiny coral polyps. It is about 2300 kilometers long. It is one of the natural wonders of the world.
Drainage
Australia receives low average rainfall. Being a hot dry country, the rate of evaporation is high in this country. So, there is a very little amount of water left to flow as river to the seas. The River Murray and its tributary are the main rivers and a major drainage basin of Australia. This drainage basin is found in the interior part of the lowlands of Australia. It covers more than one million sq km which is about 14 per cent of area of Australia.
Do You Know?
Bourke is the place in Australia where the highest temperature is recorded (53 degree celsius). It is located in the central low lands. The lowest temperature of the country is recorded in Canberra, the capital of Australia (minus22 degree celsius).
River Murray is the longest river in Australia. It runs 2508 kilometer from Australian Alps to the Indian Ocean. Darling, Alexandria, Murrumbidgee, Lachlan and Swan are the other important rivers of this continent.
Climate
Australia contains the second largest area of extremely arid land in the world. The Tropic of Capricorn divides the Australia into two equal parts. The Northern half is in the warm tropical zone and the southern half is in the cool temperate zone. The north coastal region experiences monsoon type of climate and there is a heavy rainfall during summer. The east coastal region receives good rainfall from south east trade wind. The hot desert climate extends from central lowlands to western shores. The rainfall in this region is less than 25centimeter per annual. Mediterranean type of climate prevails in the southern tip of Australia in the region around Perth and Adelaide. Tasmania gets rain throughout the year from westerly winds.
Flora and Fauna
Australia is a semi-arid region. Hence, the vegetative cover is not mainly composed of trees but of scattered shrubs and herbs. Bird's eye view of Australia would reveal a very simple vegetation pattern. The plants and trees in Australia are adapted to dry conditions and can survive for long period without water. They are called Xerophytes. Eucalyptus is the most common tree in the west as it can withstand long period of drought. Forests and woodlands together represent about 16 per cent of the area of Australian continent. Eucalyptus, Acacia and Melaleuca (swamp forests) are the major trees of Australia. About 80 percent of animals in this country are not found in the other parts of the world. Australia has almost 400 mammal species and about 140 species of marsupials. These are the animals that carry their young ones in their pouches. Kangaroo is the national animal of Australia. Koala, platypus Wallaby and Dingo are the other important animals of Australia. The bird species like the laughing kookaburra, emu, and rainbow lorikeet are the major birds of Australia.
Do You Know?
The people who work in the sheep stations in Australia are known as Jackaroos. Aborigines are the indigenous people of the Australia.
Economic Activities
Agriculture, forestry, fishing, mining, manufacturing, trade and services are the major economic activities of Australia. Wheat is the chief grain crop of Australia. Rice, sugarcane Mediterranean fruit like grapes, oranges and apricots are produced around Perth, Adelaide and Melbourne. Tasmania is known as the Apple Island. Rice, tobacco and cotton are grown in the northern parts of Tasmania. Sheep rearing is carried out along with cultivation in the regions of warm climate. Oats, maize and barley are also cultivated to some extent. Australia is well known for Vineyards and Orchards. Cattle rearing is common in the tropical savannas and sheep farming in the temperate grassland. Merino sheep are rearing in southern Australia, Tasmania, Victoria and New South Wales. Dairy cattle are reared in farms close to the cities of east and south coast. Among dairy cows Illawarra, Jersey and Ayrshire are the most popular in Australia. Fishing is also a major economic activity of Australia. Marine fishing is popular in the entire coastal regions of the country. Inland fishing is very limited. Forest resources are also very limited in the country.
Do You Know?
The sheep industry is well developed in Australia. The wool is described as the 'Cash Crop' of Australia.
Mineral Resources
Minerals are the largest export item of Australia. It contributes about 10 percent of country's GDP. Australia is the world's leading producer of bauxite, limonite, rutile and zircon, the second largest producer of gold, lead, lithium, manganese ore and zinc, the third largest producer of iron ore and uranium and the fourth largest producer of black coal. The coal belts of the country stretches from New Castle to Sydney on the south eastern coast. Iron ores are found mainly in southern and Western Australia. Bauxite is mined around the gulf of Carpentaria, perth and Tasmania. Petroleum and natural gas is obtained from Bass Strait and west of Brisbane. Uranium is mined in northern territory at Ram jungle and Queensland. Gold is mined in the western desert at Kalgoorlie and Koolgarlie. Lead, Zinc, Silver, Manganese, Tungsten, Nickel and copper are also mined in parts of Australia.
Industries
Food and beverage manufacturing industry is the primary industry in Australia. Finance, ship building, information and technology, mining, aviation and telecommunication industries are the other important industries.
ACTIVITYThere are eight deserts in Australia. List them out with the help of Atlas. Do You Know?
The temperate grass land of Australia is known as Downs
Transport
Many forms of transports are available in Australia. This country is highly dependent on road transport. There are more than 30 airports with paved runways. Passenger rail transport includes widespread commuter networks in the major cities with limited intercity and interstate networks.
Population
As of 2019 the population of Australia is about 25.2 million. It constitutes only 0.33 Percentage of the total world's population. The population density of Australia is 3 persons per sq km. Urban population of the country is about 85.7 percent. Southeastern part of Australia is the densely populated region.
Antarctica
Location and Size
Antarctica is a unique continent but it does not have a native population. There is no country in Antarctica. Antarctica is the southernmost and fifth-largest continent in the world. Since it is located in the polar region, it is the coldest continent with a permanent cover of ice. It is separated from the rest of the world by the icy water of the southern portions of the Indian, Atlantic and Pacific Oceans. It covers about 9.3% of the earth surface with an area of over 14 million sq km. This continents landform consists of some mountain ranges, peaks, valleys, glaciers plateau, ice shelf, lakes and volcanoes. The length of the Trans-Antarctic mountain is 3200 km which divides the entire continent into two halves: 1. West Antarctica 2. East Antarctica The West Antarctica faces the Pacific Ocean. The Antarctic Peninsula which points towards the South America shows that it is the continuation of the Andes mountain range. The East Antarctica faces the Atlantic and the Indian Oceans. The Mt. Erebus in this region is an active volcano. It is located in the Ross Island. It is the only continent called white continent. In some places its ice cap is 4,000 meters deep.
Do You Know?
Scientist of any country are free to conduct experiments and collect data from antartica. Hence it is called continent of Science
Climate
The climate of Antarctica is freezing cold, because of its distance from the Equator. During the months of May, June and July (winter period of Antarctica) the sun never rises in this region. So, the temperature at the South Pole falls to minus 90 degree Celcius. In the summer months of December, January and February, the sun never sets and there is a continuous day light. The summer temperature is about 0 degree Celcius. Extremely Cold and icy winds blow throughout the year.
Do You Know?
Antarctica is the largest piece of ice on the surface of Earth. About 70 Percentage of Earth's fresh water is in the Antarctic ice cap.
Flora and Fauna
Since the temperature is below freezing point almost throughout the year, no major vegetation is found in this continent. Simple plants like algae, mosses, liverworts, lichens and microscopic fungi can survive and grow in Antarctica. Some algae live in the snow, while other plants grow on the coastal rocky land that is ice free. A few species of plants, such as plankton, algae and mosses are seen in and around Antarctica's fresh and saltwater lakes.
Do You Know?
Vinson Massif (5140 m) is the highest peak in Antarctica. It is located in the southern part of Sentinel Range. Lambert glacier of this continent is the largest glacier in the world.
Small red fish called krill are found in large shoals. It is the food for many warm blooded sea animals. The living creatures of this region are include whales, seals, walrus and sea birds like penguins, albatross, polar Skua and Stout. The blue whale is the largest animal which feeds on plankton. All these animals and birds have a thick layer of fat called blubber which helps them to withstand the cold condition. Penguin birds in Antarctica cannot fly. They have webbed feet and flipper instead of wings. Small invertebrates are the only land animals which lives in the continent.
Minerals
Scientific studies show that the Antarctic continent is to be rich in gold, platinum, nickel, copper and petroleum. Traces of chromium, lead, molybdenum, tin, uranium, and zinc are also seen. The possible resources of this region also include silver, platinum, iron ore, cobalt, manganese and titanium. Coal and hydrocarbons have been explored in minimal non-commercial quantities.
Do You Know?
1. Mcmurdo is the largest research station in Antarctica. It was set up by the United States of America.
2. Dakshin Gangotri was the first Indian Scientific research base station in Antarctica.
The international agreement on this continent does not permit the extraction of minerals. So, the extraction of minerals does not take place.
Expedition to Antarctica
In 1912, British and Norwegian teams reached the South Pole. Indian expedition team to Antarctica had 21 members with Dr. S. Z. Quasim as its leader. The team left Goa on 6th December 1981 and landed in Antarctica on 9th January 1982. Dakshin Gangotri, the first Indian scientific research station was established in this continent. Maitri and Bharathi are the other research stations of India in Antarctica.
Aurora
A natural Curtain of combination of bright pink, red and green colour light that appears in the sky near the north and south magnetic poles is called Aurora. The effect is caused by the interaction of charged particles from the sun with atoms in the upper atmosphere. It is also called Aurora Australis or Southern Lights in the South Pole and Aurora Borealis or Northern Lights in the North Pole. These amazing colours appear in the earth's sky, especially in the high latitudinal countries like Alaska in the north and New Zealand of Falkland in the south.
Recap
1. Africa consists of a mixture of landforms such as mountains, plateaues and plains.
2. Australia is the largest island and smallest continent in the world.
3. Antarctica is the southernmost and fifth largest continent in the world.
4. The interaction of charged particles from the sun with atoms in the upper atmosphere is called Aurora.
Glossary
Continent (n) A large land mass கண்டம் Strait (n) A narrow water channel which connect two large water bodies and separates two land masses. நீர்ச்சந்தி Isthmus (n) A narrow strip of land that connects two large land masses and separate two water bodies. நிலச்சந்த Gulf (n) A deep inlet of the sea, surrounded by a narrow mouth. வளைகு்டா Rift Valley (n) A linear shaped low land between the mountains. பிளவு பள்ளத்தாக்கு Reef (n) A thin layer of calcium carbonate. பவளப்பாறை Cataracts (n) A fast flowing water falls over a cliff. சிறு அருவி Pinnacles (n) Pointed limestone pillars found in Australian desert. சுண்ணாம்ப்பாறைத் தூண் Regs (n) These are plains of sand and gravel in the arid regions. மணற்பாங்கான சமவெளி Hamada (n) Elevated plateaus of rock and stones. பாளை மறறும் கற்களால் உயரத்பபட்ட பீ்டபூமி Oasis (n) A hub of water in the desert region. பாலைவனச் சோலை
Evaluation
Exercise 1. Choose the correct answer
1. The southernmost tip of Africa is.
a) Cape Blanca b) Cape Agulhas c) Cape of Good Hope d) Cape Town
2. The manmade canal through an isthmus between Egypt and Sinai Peninsula is
a) Panama Canal b) Aswan Canal c) Suez Canal d) Albert Canel
3. In respect of the Mediterranean climate, consider the following statements and choose the correct answer.
1. The average rainfall is 15cm
2. The summers are hot and dry; winters are rainy.
3. Winters are cool and dry; Summers are hot and wet
4. Citrus fruits are grown
a) 1 is correct b) 2 and 4 are correct c) 3 and 4 are correct d) All are correct
4. The range which separates the west and east flowing rivers in Australia is
a) Great Dividing Range b) Himalayan range c) Flinders range d) Mac Donnell range
5. Kalgoorile is famous for mining.
a) Diamond b) Platinum c) Silver d) Gold Exercise 2. Fill in the blanks
1. Atlas Mountain is located in continent.
2. is the highest peak of Africa.
3. is the most common tree in Australia.
4. A temperate grass land of Australia is called .
5. is the first Indian research station in Antarctica.
Exercise 3. Match the following
| 1. Pinnacle | |
| 2. Krill | |
| 3. Ostrich | |
| 4. Lake Eyre | |
| 5. Jewel of the earth | |
Options: Equatorial forest, salt lake, small red fish, flightless bird, pointed limestone pillars
Exercise 4. Let us learn
1. Assertion (A): Aurora is a curtain of colour lights appear in the sky.
Reason (R): They are caused by magnetic storms in the upper atmosphere.
a) Both A and R are individually true and R is the correct explanation for A. b) Both A and R are individually true but R is not the correct explanation for A c) A is true but R is false. d) R is true but A is false
2. Assertion (A): A geological feature of Africa is the Great Rift Valley.
Reason (R): A Rift valley is a large crack in the earth's surface formed by tectonic activity.
a) Both A and R is individually true and R is the correct explanation for A. b) Both A and R are individually true but R is not the correct explanation for A c) A is true but R is false. d) R is true but, A is false Exercise 5. Answer briefly
1. Why Africa is called a "Mother Continent"?
2. What are the important rivers of Africa?
3. Name the physical division of Australia.
4. Write about the nature of Antarctic continent.
5. Mention any four economic activities of Australia.
Exercise 6. Distinguish between
1. Sahel and Sahara
2. Western Antarctica and Eastern Antarctica
3. Great Barrier Reef and Artesian Basin.
Exercise 7. Give reasons
1. Egypt is called the gift of the Nile.
2. Deserts are found in the western margins of continents.
3. Antarctica is called the continent of scientists
Exercise 8. Answer in a paragraph
1. Give an account on mineral wealth of Australia.
2. Describe the flora and fauna of Antarctica
3. Name the physical divisions of Africa and explain any one.
Exercise 9. Map skill
Mark the following on the outline map of Africa and Australia
Africa: Equator, Atlas Mountain, Sahara, Eastern highlands, Mediterranean Sea, Atlantic Ocean, Indian Ocean, Suez Canal, Mount Kilimanjaro
Australia: Great Dividing Range, Great barrier reef, Tasmania, tropic of Capricorn, pacific ocean, Great Australian Sandy Desert, Indian ocean, Sydney, Canberra
Exercise 10. Activities
1. Find out the hemisphere and season during December for the following countries
| Country | Hemisphere | Season |
|---|
| South Africa | | |
| Morocco | | |
| Australia | | |
| Niger | | |
| Egypt | | |
| Tasmania | | |
| India | | |
2. Label the different states of Australia in the following map.
REFERENCE BOOKS
1. Richard G. Boehm (2002), World Geography, Texas Edition McGraw Hill/Glencoe, USA.
2. Jojo Mathew (2017), India and World Geography, Wizard India private limited, New Delhi.
3. Majid Husain (2017) India and World Geography, McGraw Hill education series private India limited, New Delhi.
INTERNET RESOURCES
https//www.gph.gov.an.pups
https//www.worldatlas.com
https//www.blogs.nasa.gov
https//www.worldwildlife.org
https//books.google.com.in.
www.waterencyclopedia.com
www.worldometers.info
www.agriculture.gov.aub.national
https://www.queensland.com
www.dk.com concise atlas of the world
https://www.earthobservatory .nasa.gov.
Book-back Exercises — Questions & Answers
Answers generated strictly from the Samacheer Kalvi textbook content. Attempt each question first, then click "Show Answer" to check.
1. Choose the correct answer
1. The southernmost tip of Africa is.
a) Cape Blanca b) Cape Agulhas c) Cape of Good Hope d) Cape Town
Answer: b) Cape Agulhas
Explanation: Cape Agulhas is the southernmost point of Africa.
2. The manmade canal through an isthmus between Egypt and Sinai Peninsula is
a) Panama Canal b) Aswan Canal c) Suez Canal d) Albert Canal
Answer: c) Suez Canal
Explanation: The Suez Canal is the manmade canal connecting Egypt and Sinai Peninsula.
3. In respect of the Mediterranean climate, consider the following statements and choose the correct answer. 1. The average rainfall is 15cm 2. The summers are hot and dry; winters are rainy. 3. Winters are cool and dry; Summers are hot and wet 4. Citrus fruits are grown
a) 1 is correct b) 2 and 4 are correct c) 3 and 4 are correct d) All are correct
Answer: b) 2 and 4 are correct
Explanation: Mediterranean climate regions get rainfall in winters while in summers it is hot and dry. Mediterranean fruit like oranges are produced in these regions.
4. The range which separates the west and east flowing rivers in Australia is
a) Great Dividing Range b) Himalayan range c) Flinders range d) Mac Donnell range
Answer: a) Great Dividing Range
Explanation: The eastern highlands are also known as the 'Great Dividing Range' as it separates the west and east flowing rivers.
5. Kalgoorlie is famous for mining.
a) Diamond b) Platinum c) Silver d) Gold
Answer: d) Gold
Explanation: Gold is mined in the western desert at Kalgoorlie and Koolgarlie.
2. Fill in the blanks
1. Atlas Mountain is located in _____ continent.
Answer: Africa
2. _____ is the highest peak of Africa.
Answer: Mt. Kilimanjaro
3. _____ is the most common tree in Australia.
Answer: Eucalyptus
4. A temperate grass land of Australia is called _____.
Answer: Downs
5. _____ is the first Indian research station in Antarctica.
Answer: Dakshin Gangotri
3. Match the following
Match the Following
| 1. Pinnacle | - Equatorial forest |
| 2. Krill | - salt lake |
| 3. Ostrich | - small red fish |
| 4. Lake Eyre | - flightless bird |
| 5. Jewel of the earth | - pointed limestone pillars |
Answers: 1-e, 2-c, 3-d, 4-b, 5-a
4. Let us learn
1. Assertion (A): Aurora is a curtain of colour lights appear in the sky. Reason (R): They are caused by magnetic storms in the upper atmosphere.
a) Both A and R are individually true and R is the correct explanation for A. b) Both A and R are individually true but R is not the correct explanation for A c) A is true but R is false. d) R is true but A is false
Answer: c) A is true but R is false
Explanation: Aurora is a natural curtain of bright colors but is caused by interaction of charged particles from the sun with atoms in the upper atmosphere, not magnetic storms.
2. Assertion (A): A geological feature of Africa is the Great Rift Valley. Reason (R): A Rift valley is a large crack in the earth's surface formed by tectonic activity.
a) Both A and R is individually true and R is the correct explanation for A. b) Both A and R are individually true but R is not the correct explanation for A c) A is true but R is false. d) R is true but, A is false
Answer: a) Both A and R is individually true and R is the correct explanation for A
Explanation: The Great Rift Valley is indeed a major geological feature of Africa, and it is formed by shifting of tectonic plates.
5. Answer briefly
1. Why Africa is called a "Mother Continent"?
Answer: Africa is nicknamed as the "Mother Continent" as it was the oldest inhabited continent on Earth. The sources reveal that the early human ancestors have lived in Africa for more than 5 million years.
2. What are the important rivers of Africa?
Answer: The important rivers of Africa are River Nile (the longest river in the world), River Congo or Zaire, River Niger, River Zambezi, River Limpopo and River Orange.
3. Name the physical division of Australia.
Answer: Based on the nature of topography, Australia can be divided into three physical divisions: 1. The Great Western Plateau 2. The Central Lowlands 3. The Eastern Highlands.
4. Write about the nature of Antarctic continent.
Answer: Antarctica is a unique continent with no native population and no country. It is the southernmost and fifth-largest continent located in the polar region. It is the coldest continent with permanent ice cover and is called the white continent.
5. Mention any four economic activities of Australia.
Answer: Agriculture, forestry, fishing, mining, manufacturing, trade and services are the major economic activities of Australia. Sheep rearing, cattle rearing, wheat cultivation and mining are important activities.
6. Distinguish between
1. Sahel and Sahara
Answer: Sahara is the world's largest hot desert located in northern Africa covering 9.2 million sq km. Sahel is a semi-arid tropical Savanna region that lies between the Sahara Desert in the north and Savanna grassland in the south, acting as a transition zone.
2. Western Antarctica and Eastern Antarctica
Answer: The Trans-Antarctic mountain divides Antarctica into two halves. West Antarctica faces the Pacific Ocean and the Antarctic Peninsula points towards South America. East Antarctica faces the Atlantic and Indian Oceans and contains Mt. Erebus, an active volcano.
3. Great Barrier Reef and Artesian Basin.
Answer: Great Barrier Reef is located along the east coast of Queensland, formed by coral polyps and stretches 2300 km. The Great Artesian Basin is the largest underground water basin in the world, providing water to arid regions and extending over 1.7 million sq km.
7. Give reasons
1. Egypt is called the gift of the Nile.
Answer: Egypt is called the "Gift of the Nile" as it is the lifeline of Egypt. Without Nile, Egypt would have been a desert. The Nile River provides water and fertile soil for agriculture in the otherwise desert region.
2. Deserts are found in the western margins of continents.
Answer: Tropical deserts are located on western margins because trade winds blow from east to west. These winds shed their moisture on the eastern margins of continents and by the time they reach the west, they lose their moisture, creating arid conditions.
3. Antarctica is called the continent of scientists
Answer: Antarctica is called the continent of science because scientists of any country are free to conduct experiments and collect data from Antarctica. It has no native population and serves as a research base for scientific studies.
8. Answer in a paragraph
1. Give an account on mineral wealth of Australia.
Answer: Minerals are the largest export item of Australia, contributing about 10 percent of the country's GDP. Australia is the world's leading producer of bauxite, limonite, rutile and zircon. It is the second largest producer of gold, lead, lithium, manganese ore and zinc. Coal belts stretch from Newcastle to Sydney, iron ores are found in southern and Western Australia. Bauxite is mined around Gulf of Carpentaria, petroleum and natural gas from Bass Strait, uranium in northern territory, and gold at Kalgoorlie.
2. Describe the flora and fauna of Antarctica
Answer: Since temperature is below freezing point throughout the year, no major vegetation is found in Antarctica. Simple plants like algae, mosses, liverworts, lichens and microscopic fungi can survive. The fauna includes whales, seals, walrus, penguins, albatross, polar Skua and blue whales. Small red fish called krill are found in large shoals. All these animals have a thick layer of fat called blubber to withstand cold conditions.
3. Name the physical divisions of Africa and explain any one.
Answer: The eight major physical divisions of Africa are: Sahara, Sahel, Savanna, The Great Rift Valley and Great Lakes, East African Highlands, Swahili Coast, The Congo Basin, and Southern Africa. Sahara is the world's largest hot desert located in northern Africa with an area of 9.2 million sq km. It is bordered by Atlantic Ocean in west, Red Sea in east, Mediterranean Sea in north and Sahel in south. Mount Koussi is the highest point and Qattara Depression is the deepest point.
📝 Summary
- Africa is the second largest and second most populous continent after Asia, covering an area of about 30.36 million square kilometres (20.2% of the world's land area) and stretching from 37°21' North to 34°51' South latitude.
- The continent is unique as it is the only one through which the major latitudes (Tropic of Cancer, Equator, and Tropic of Capricorn) pass, with the equator cutting Africa into two equal halves and making it located in all four hemispheres.
- Africa is nicknamed the "Mother Continent" as it was the oldest inhabited continent on Earth, where early human ancestors have lived for more than 5 million years, and consists of 54 countries grouped into five regions based on geographical location.
- The Sahara Desert, located in northern Africa, is one of the largest hot deserts in the world with an area of 9.2 million sq km, covering 11 countries and containing diverse topographical features including Mount Koussi (3,445 m) as its highest point.
- Africa's diverse geographical conditions include a mixture of landforms such as mountains, plateaus, and plains, with major physical divisions including the Sahara Desert and the Atlas Mountain range, which is a young fold mountain with Mount Toubkal (4167m) as its highest point.