MAJOR DOMAINS OF THE EARTH

1 MAJOR DOMAINS OF THE EARTHAs you have read in the first chapter, the EARTH is theonly planet which has life. Human beings can live herebecause the life sustaining elements of land, water andair are present on the surface of the EARTH is a complex zone in whichthree main components of the environment meet,overlap and interact. The solid portion of the EARTH onwhich we live is called the Lithosphere. The gaseouslayers that surround the EARTH , is the Atmosphere,where oxygen, nitrogen, carbondioxide and other gasesare found. Water covers a very big area of the EARTH ssurface and this area is called the Hydrosphere.

2 TheHydrosphere comprises water in all its forms, that is,ice, water and water Biosphere is the narrow zone where we findland, water and air together, which contains all formsof solid portion of the EARTH is called the comprises the rocks of the EARTH s crust and the thinlayers of soil that contain nutrient elements whichsustain are two main divisions of the EARTH s large landmasses are known as the continentsand the huge water bodies are called the ocean the oceans of the world are connected with oneanother. Look at the map of the world (Figure ). Areall the land masses connected with one another?

3 The level of seawater remains the same of land is measured from the level of the sea,which is taken as OriginIn the Greeklanguage, Lithosmeans Stone; Atmosmeans Vapour;Hudor means Water;and Bios means you make words usingthe above?2022-2331 MAJOR DOMAINS OF THE EARTHF igure : The World : Continents and OceansSOUTHERN OCEAN2022-2332 THE EARTH : OUR HABITATThe highest mountain peak Mt. Everest is 8,848metres above the sea level. The greatest depth of 11,022metres is recorded at Mariana Trench in the PacificOcean. Could you imagine that depth of sea is muchmore than the highest point?

4 ContinentsThere are seven MAJOR continents. These are separatedby large water bodies. These continents are Asia,Europe, Africa, North America, South America,Australia and Antarctica. Look at the map of the world(Figure ) and notice that the greater part of the landmass lies in the Northern is the largest continent. It covers about one-third of the total land area of the EARTH . The continentlies in the Eastern Hemisphere. The Tropic of Cancerpasses through this continent. Asia is separated fromEurope by the Ural mountains on the west ( ). The combined landmass of Europe and Asia iscalled the Eurasia (Europe + Asia).

5 Europe is much smaller than Asia. The continentlies to the west of Asia. The Arctic Circle passes throughit. It is bound by water bodies on three sides. Look atthe map of the world and locate is the second largest continent after Equator or 00 latitude runs almost through themiddle of the continent. A large part of Africa lies inthe Northern Hemisphere. Look at the Figure ; youwill find that it is the only continent through whichthe Tropic of Cancer, the Equator and the Tropic ofCapricorn Sahara Desert, the world s largest hot desert,is located in Africa.

6 The continent is bound on all sidesby oceans and seas. Look at the world map (Figure ).You will notice that the world s longest river the Nile,flows through Africa. Notice where the Equator, theTropic of Cancer and the Tropic of Capricorn pass inthe map of America is the third largest continent of theworld. It is linked to South America by a very narrowstrip of land called the Isthmus of Panama. Thecontinent lies completely in the Northern and WesternHemisphere. Three oceans surround this you name these oceans?Do you know?Edmund Hillary(New Zealand)and Tenzing NorgaySherpa (India) were thefirst men to climb thehighest mountain peak on the planetearth on 29th May, Tabei (Japan)was the first woman toreach the summit on 16thMay, 1975.

7 The firstIndian woman to climb thehighest peak on 23rd May,1984 was Bachendri DOMAINS OF THE EARTHS outh America liesmostly in the SouthernHemisphere. Which twooceans surround it onthe east and the west?The Andes, world slongest mountainrange, runs through itslength from north tosouth (Figure ).South America has theworld s largest river , is thesmallest continent thatlies entirely in theSouthern is surrounded on allsides by the oceans andseas. It is called anisland , completely in the Southern Hemisphere,is a huge continent. The South Pole lies almost at thecentre of this continent.

8 As it is located in the SouthPolar Region, it is permanently covered with thick icesheets. There are no permanent human countries have research stations in also has research stations there. These are namedas Maitri and Dakshin EARTH is called the blue planet. More than 71 percent of the EARTH is covered with water and 29 percent is with land. Hydrosphere consists of water inall its forms. As running water in oceans and riversand in lakes, ice in glaciers, underground water andthe water vapour in atmosphere, all comprise than 97% of the EARTH s water is found in theoceans and is too salty for human use.

9 A largeproportion of the rest of the water is in the form oficesheets and glaciers or under the ground and a verysmall percentage is available as fresh water for humanFigure : Isthmus and StraitName the Straitbetween Indiaand Sri EARTH : OUR HABITATuse. Hence, despite being a blue planet we face ashortage of water!!OceansOceans are the MAJOR part of hydrosphere. They areall ocean waters are always moving. The three chiefmovements of ocean waters are the waves, the tidesand the ocean currents. The five MAJOR oceans are thePacific Ocean, the Atlantic Ocean, the Indian Ocean,the Southern Ocean and the Arctic Ocean, in order oftheir size (Figure ).

10 The Pacific Ocean is the largest ocean. It is spreadover one-third of the EARTH . Mariana Trench, the deepestpart of the EARTH , lies in the Pacific Ocean. The PacificOcean is almost circular in shape. Asia, Australia,Figure : Comparative size of the continentsCount the squares given in Figure and answer the following :(a) Name the largest continent; (b) Which is larger Europe or Australia?2022-2335 MAJOR DOMAINS OF THE EARTHN orth and South Americas surround it. Look at the mapand find out the location of the continents around thePacific Atlantic Ocean is the second largest Ocean inthe world.