NCERT CLASS-6 GEOGRAPHY
CHAPTER-5 [MAJOR DOMAINS OF THE EARTH]
- The solid portion of the earth on which we live is called the Lithosphere.
- The gaseous layer that surround the earth is the Atmosphere.
- Water covers a very big area of the Earth’s surface and this area is called the Hydrosphere.
- The biosphere is the narrow zone where we find land, water and air together, which contains all forms of life.
- Two main divisions of earth’s surface- continents and oceans basins.
- Level of sea water remains the same everywhere.
- Elevation of land is measured from the level of the sea, which is taken as zero.
- The highest mountain peak Mt. Everest is 8848 m above the level.
- The greatest depth of 11,022 m is recorded at Mariana Trench int the Pacific Ocean.
- Edmund Hillary (New Zealand) and Tenzing Norgay Sherpa (India) were the 1st men to climb the Mt. Everest on 29th May 1953.
- Junko Tabei (Japan) was the 1st woman to reach the summit on 16th May 1975.
- The 1st Indian woman to climb the highest peak on 23rd may, 1984 was Bachendri Pal.
- Continents- 7 major- Asia, Europe, Africa, North America, South America, Australia and Antartica.
- Asia, largest continent, covers about of the total land area of the earth.
= lies in eastern hemisphere, Tropic of Cancer passes through Asia.
= Asia is separated from Europe by the Ural Mountains on the west.
= Europe+Asia combined - Eurasia.
- Europe, smaller than Asia, lies to west of Asia.
= Artic circle passes through Europe, bound by water bodies on 3 sides.
- Africa is the second largest continent, equator runs almost through middle of the continent, large part lies in Northern Hemisphere.
= only continent through which Tropic of Cancer, equator, Tropic of Capricorn
pass.
= Sahara desert is located in Africa, bound on all sides by oceans and seas.
= World longest river the Nile, flows through Africa.
- North America is the 3rd largest continent.
= linked to South America by a very narrow strip of land called the Isthmus of
Panama.
= lies completely in Northern & Western Hemisphere, surrounded by 3 oceans.
- South America lies mostly in the Southern Hemisphere.
= The Andes, world’s longest mountain range, runs through its length from north
to south.
= has the world’s largest river, the Amazon.
- Australia, smallest continent, lies in Southern Hemisphere.
= surrounded on all sides by oceans & seas.
= called Island continent.
- Antarctica, completely in the Southern Hemisphere, huge continent.
- South Pole lies almost at the centre of this continent.
= permanently covered with thick ice sheets.
= India research stations in Antarctica - Maitri and Dakshin Gangotri.
- Isthmus- a narrow strip of land joining two landmasses.
- Strait- A narrow passage of water connecting two large water bodies like seas and oceans.
- Earth is called Blue planet.
- More than 71% covered by water and 29% with land.
- More than 97% of the earth’s water is found in the oceans and is too salty for human use.
=large proportion in the form ice sheets and glaciers.
= a very small % is available as fresh water for human use.
- Oceans are all interconnected.
= 3 chief movements of oceans water are the waves, the tides and the ocean
currents.
- 5 major oceans- Pacific Ocean, the Atlantic Ocean, Indian Ocean, the Southern ocean and the Arctic ocean in order of their size.
- Pacific Ocean, the largest ocean, spread over one-third of the earth.
= Mariana Trench, the deepest part of the earth, lies in the Pacific Ocean, ocean
is almost circular in shape.
= Asia, Australia, North and South America’s surround it.
- Atlantic Ocean, 2nd largest ocean, it is ‘S’ shaped.
= The coastline of Atlantic Ocean is highly indented.
= From p.o.v. Of commerce, it is the busiest ocean.
- Indian Ocean shape is almost triangular.
= in north, bound by Asia, west by Africa and east by Australia.
- Southern ocean encircle the continent of Antarctica and extends extends northward to 60° south latitude.
- Arctic Ocean, located within the Arctic circle, surrounds the North Pole.
= connected with Pacific Ocean by a narrow stretch of shallow water known as
Berring Strait.
= bound by northern coasts of North America and Eurasia.
- Earth surrounded by a layer of gas called Atmosphere.
= The atmosphere extends up to 5 layers based on composition, temperature and
Other properties, starting from earth’s surface- Troposphere, Stratosphere,
Mesosphere, Thermosphere, Exosphere.
= atmosphere composed mainly of nitrogen and oxygen, makes 99% of clean,
dry Air.
= Nitrogen 78%, Oxygen 21% and other gases, like carbon dioxide, argon, ….,
1% by volume.
- CO2 is important as it absorbs the heat radiated by the earth.
= essential for the growth of plants.
- The density of atmosphere varies with height, maximum at sea level and decreases as we go up.
- Atmosphere also exerts pressure on thr earth, varies from place to place.
= Air moves from high pressure to low pressure.
= Moving air is known as wind.
- Biosphere is the narrow zone of contact between the land, water and air.
- CO2 is an important constituent of air, but increase in the amount of CO2 leads to global warming.