L. R. & S. M. VISSANJI ACADEMY
SECONDARY SECTION - 2016-17
GEOGRAPHY - GRADE: VI
OUR ENVIRONMENT
Four Realms of the Earth’s Environment
 Lithosphere: The outer solid layer of the earth is called Lithosphere. It is made of rocks and layers of
soil.
 Hydrosphere: All the water bodies such as oceans, seas, rivers and lakes together make up the
hydrosphere.
 Atmosphere: The layer of air surrounding the Earth.
 Biosphere: The layer which contains all forms of life. (Broadly classified into plant kingdom and
animal kingdom.
The continents
Asia
Africa
North
America
South
America
Australia
Europe
Antarctica
















Largest continent
It occupies one third total land area .Asia and Europe together called Eurasia.
Asia is separated from Europe by the Ural Mountains.
The second largest continent of the world.
Tropic of cancer, the equator and Tropic of Capricorn passes through this
Continent.
Asia and Europe are collectively called Afro-Asia.
Third largest continent of the world.
Panama is considered southern boundary.
Fourth largest continent.
Isthmus of Panama links North America and South America.
It is smallest continent.
Known as island continent.
It lies in the west of Asia.
Continent is bounded by water bodies on three sides.
Located in the South Polar Region.
Permanently covered with thick ice sheets, known as the ‘White Continent’.
Major Landforms
Mountains
Mountains is a large mass of land that
rises to great height, above the
surrounding area
 The glaciers in the mountains give
rise to many perennial rivers, which
provide water through the year.
 Provides minerals.
 Home to a variety of wildlife.
 Ideal tourist spots.
 Provide water for irrigation,
generation of electricity and
navigation.
Plateaus
Extensive areas of upland bounded
by steep slopes on one or more sides.
It is also called table land.
 Rich in mineral deposits e.g.
Chota Nagpur plateau of India.
 Volcanic plateaus are extremely
fertile.
 Attractive tourist spots.
 Sites are ideal for hydro- electric
power generation.
Plains
Plains: Vast extent of flat area
of land formed by deposition
of alluvium.
 Fertile Soil provides ideal
condition for agriculture.
 Coastal plains help in
navigation.
 Flat surface helps in the
construction of transport
network, building and
industries.
Hydrosphere:
Oceans: Vast bodies of water surrounding the continents.
The Four major oceans:
1. Pacific Ocean
 Largest and deepest ocean
 Surrounded by the continents of North America and South America towards east Asia and
Australia towards west.
2. The Indian Ocean
 It is named after India.
 Africa lies to the west, Asia lies to its north and Australia to its east.
3. The Arctic Ocean
 The smallest ocean located in the polar region.
 Water remains frozen throughout the year.
4. Atlantic Ocean
 Second largest Ocean. It is shaped like the letter ‘S’
Importance of Hydrosphere
 Maintains the hydrological cycle.
 Store houses of minerals ,fishes and energy
 Oceans link the continents through shipping routes.
 Rivers and other water bodies provide fresh water for our requirements.
Atmosphere
 The Atmosphere consists of a mixture of gases (Nitrogen 78%, oxygen 21%, carbon dioxide,
argon and others 1%).
 Nitrogen and oxygen are the two abundant gases in the atmosphere.
 Carbon dioxide is absorbed by plants.
 Increase in level of carbon dioxide in the air is harmful for human beings.
Importance of Atmosphere
 Prevents the escape of heat from the Earth.
 Prevents us from harmful effects of sun’s rays.
 Acts as a blanket to maintain an optimum temperature on the Earth.
Biosphere
 The organisms in the biosphere can be broadly divided into plant kingdom and animal
kingdom.
 It is the narrow zone of contact between land, water and air.