Major domains of the Earth

Cbse class 6, Social Studies

MAJOR DOMAINS OF THE EARTH

Life in Earth is possible because of land, water and air
Environment is divided into Physical and biological environment
Physical environment is made up of Land, air and water
It is essential for existence of different life forms
Biological environment is made up of Plants, animals
It is essential for survival, and it provides food
Our Environment consist of four realms. They are

Lithosphere
Hydrosphere
Atmosphere
Biosphere

Lithosphere

Lithosphere is a solid surface of Earth, living things exist here
Innermost and hottest layer of Earth is called as Core
Layer of molten rock that surrounds core is called as Mantle
Solid, rocky, uppermost part of Earth is Crust
Crust and rigid upper layers of mantle together form Lithosphere

Two types of Lithosphere:

Continental and Oceanic Lithosphere
Lithosphere is made up of fragments called as Lithosphere Plates
Lithosphere plate float on molten part of Mantle and often keep colliding

Importance of Lithosphere:

Life exists in Lithosphere
Lithosphere consist of rocks, minerals, precious stones, minerals and materials used in the production of energy

CONTINENTS:

Huge Landmasses on the Earth is called as Continents.

There are totally seven continents. They are

Asia
Africa
Australia
Antarctica
North America
South America
Europe

ASIA:

One third of Earth surface, the largest and most populous (populated ) continent is Asia
Asia lies in Northern Hemisphere. Asia is located in East of Prime meridian and in Eastern hemisphere

Borders of Asia are:

North – Arctic Ocean
East – Pacific Ocean
West – Europe
South – Africa

Tropic of cancer passes through Asia Continent
Asia is separated from Europe by Ural Mountains, Black sea and Caspian sea
Main Geographical feature in Asia is Ural Mountains, Europe

EUROPE:

Europe is the sixth largest continent
Peninsula is a narrow strip of land projecting into sea/lake from mainland
Europe is a Peninsula with water bodies surrounding it on three sides

Europe is surrounded by

North – Arctic Ocean
West – Atlantic Ocean
South – Mediterranean Sea and Africa

Prime Meridian, Arctic circle passes through Europe
Highest Mountain range in Europe is Alps
Mount Blanc is the highest peak of Alps

AFRICA:

Africa is the second largest continent in the World

Africa is separated by

Suez canal from Asia
Strait of Gibraltar from Europe
Equator passes through the Centre of Africa

Africa lies partly in Northern and Southern Hemisphere
Tropic of Cancer passes through Northern Africa
Tropic of Capricorn passes through Southern Africa
Sahara is the largest and hottest desert in Africa

NORTH AMERICA:

North America is the Third largest continent
North America lies in Northern Hemisphere

Borders of North America:

East – Atlantic Ocean
West – Pacific Ocean
South – South America (Isthmus of Panama)

75% of North America is Canada, USA
Rest is Greenland, Caribbean island (West Indies)
Geographical feature of North America is Desert, Temperate forest, Taiga vegetation, grassland

SOUTH AMERICA:

South America is fourth largest continent and fifth populated continent
Most of the South America lies in Southern and in Western hemisphere
Equator passes through the Northern most part of South America

Borders of South America is

East – Atlantic Ocean
West – Pacific Ocean

South America has largest mountain range Andes and World largest river Amazon

AUSTRALIA:

Australia is smallest and island continent
Australia lies in Southern hemisphere
Australia located in South East Asia
Australia is border by Indian Ocean and Pacific Ocean
New Zealand, New Guinea and several other island altogether form the Australasia
Australia has Rainforest, Desert, Savannah, Vegetation and Temperate forest

Geographical feature of Australia is

Great dividing range
Central lowland
Western Desert
Great Barrier reef

ANTARTICA:

Fifth largest continent is Antarctica.
It is also called as White and Frozen continent
Antarctica is windiest, iciest, driest place on Earth
Antarctica is surrounded by Pacific Ocean, Atlantic Ocean, Indian Ocean
Research stations of various countries are set up in Antarctica for various studies
India’s two research station in Antarctica are Maitri and Dakshin Gangotri

HYDROSPHERE

Earth’s ocean, lakes, glaciers, water vapour and clouds comprise Hydrosphere
Two third of Earth is covered with water in the form of Seas and Oceans
Oceans are larger than seas

Five major oceans are

Pacific Ocean
Atlantic Ocean
Indian Ocean
Arctic Ocean
Southern Ocean

World’s largest sea are

South China Sea
Caribbean Sea
Mediterranean Sea
Bering Sea
Deepest and largest ocean of the world is Pacific Ocean
Pacific Ocean bounded on
West – Asia and Australia
East – North and South America
Pacific Ocean covers one third of Earth surface
Ferdinand Magellan named Pacific Ocean meaning Calm or Tranquil
International Date line passes through Pacific Ocean
Deepest part of World Ocean is Mariana Trench is present in Pacific Ocean
Second largest, S shaped Ocean is Atlantic Ocean
Atlantic Ocean is busiest ocean for Trade and commerce
Atlantic Ocean coastline is Intended provides good site for Sheltered harbour

What is Intended? What is the benefit for coastline indented?

Intended means uneven edges/ surface with parts worn away
When the coastline is intended, deep water come close to harbour and provide large entrance for ships
Harboured sheltered in indented coast is protected from
Strong winds
Dangerous currents
Only ocean named after a country is Indian Ocean

Indian Ocean bordered by

West – Africa
North – Asia
East – Australia

Smallest ocean in the world is Arctic Ocean
Bering Strait connect Arctic Ocean with Pacific Ocean
For most of the year, Arctic Ocean remains Frozen
Southern Ocean encircles the continent of Antarctica
Southern Ocean comprises Southern portion of Pacific, Atlantic, Indian Ocean

ATMOSPHERE

Surface of Earth is surrounded by a blanket of gases called Atmosphere

There are 5 distinct layers in the atmosphere

They are

Troposphere
Stratosphere
Mesosphere
Thermosphere
Exosphere

Layers of atmosphere are result of Temperature changes, occurring in various altitudes

Lowest layer of atmosphere is Troposphere
Temperature in this layer decreases by 1 degree for every 165 Km elevation
Clouds, lightening occur in Troposphere
Atmospheres contain Ozone
Ozone shield from UV radiation of the Sun
Ozone helps to maintain even temperature

Ozone is a thin layer that helps to

Allow warmth of sunrays to reach us
Prevents internal heat from escaping Earth surface
Atmosphere contain 21% oxygen which is essential for respiration
Atmosphere contain 78% Nitrogen, source of Proteins for all living organism
Carbon di oxide present in air used by green plants to make carbohydrates (Food)
Water vapour present in air prevent from
Body drying
Act as a source of drinking water
Near surface of Earth, atmosphere densest and air pressure is maximum
When altitude increases, Density of air decreases

Temperature decreases

Air pressure decreases

BIOSPHERE

The region between the surface and atmosphere of Earth is Biosphere
Biosphere is occupied by living organism
Vegetation and animal life varies in different part of Earth due to different climate
The distinct zones of the biosphere each with its own climate, plant, animal life are called as Ecosystem
Animals with thick fur found in cold regions
Cactus plant grow in deserts
Rice grows in tropical regions
Reasons behind rapid loss of natural resources is
Deforestation
Converting agricultural land into industries and settlements
Pollution
150 government leaders signed the convection of biological diversity in 1992 at Rio Earth submit