NCERT Class 6 Geography Chapter 5 Notes. The Earth’s surface is a complex zone in which three main components of the environment meet, overlap, and interact. (1) Lithosphere (2) Hydrosphere and (3) Atmosphere. And the Biosphere is the narrow zone where land, water, and air interact and all forms of life are found on the Earth.
The upper solid layer of the earth is called the Lithosphere. It comprises the rocks and soil that contain nutrients and minerals to support life on the Earth.
There are two main divisions of the earth’s surface.
(1) Continents – Large landmasses
(2) Ocean Basins – Bottom of the huge water bodies
> Largest continent. (one-third of the total land area of the earth).
> lies in the Eastern Hemisphere.
> The Tropic of Cancer passes through this continent.
> Separated from Europe by the Ural mountains on the west.
> Europe+Asia = Eurasia
> Lies to the west of Asia.
> The Arctic circle passes through it.
> Bound by water bodies on three sides.
> second largest continent after Asia.
> The Equator passes through the middle of the continent.
> A large part of Africa lies in the Northern Hemisphere.
> Only continent through which the Tropic of Cancer, the Equator, and the Tropic of Capricorn pass.
> Bound on all sides by oceans and seas.
> Home to the world’s largest hot desert (Sahara Desert) and the world’s longest river (Nile River).
> Third-largest continent in the world.
> Linked to South America by Isthmus of Panama.
> Lies completely in the Northern and Western Hemisphere.
> Lies mostly in the Southern Hemisphere.
> The world’s longest mountain range (Andes Range) runs through its length from north to south.
> The world’s largest river (Amazon River) flows through this continent.
> Smallest continent.
> Lies entirely in the Southern Hemisphere.
> Island continent.
> Lies completely in the Southern Hemisphere.
> It is a large continent.
> The South Pole lies almost at the center of this continent.
> Permanently covered with thick ice sheets because of the South Polar region.
> No permanent human settlement.
More than 71% of the earth is covered with water. Hence, it is called a blue planet. It consists of water in all its forms. (Running Water, frozen water, water vapor)
The Pacific Ocean
> largest ocean. Covers over one-third of the earth.
> The deepest part of the Earth (Mariana Trench) lies in the Pacific Ocean.
> Circular in shape.
> Surrounded by Asia, Australia, North America, and South America.
> second largest ocean in the world.
> Surrounded by North America and the South Americas on the Western side and Europe and Africa on the eastern side.
> Highly indented coastline which is an ideal location for natural harbors and ports.
> Commercially, it is the busiest ocean.
> Only ocean named after a country (India).
> The shape of the ocean is triangular.
> Bound by Asia in the north, Africa in the west, and Australia in the east.
> Located within the Arctic Circle and surrounds the North Pole.
> Connected with the Pacific Ocean by a narrow stretch of shallow water known as Bering Strait.
> Shape of a ring.
> Surrounding Antarctica.
The thin blanket of air around the Earth is called the atmosphere. It provides us with the air we breathe and protects us from the harmful effects of the sun’s rays.
The atmosphere is divided into 5 layers and it is extended up to 1600 km.
Important Gases of the Atmosphere
> Nitrogen (78%)
> Oxygen (21%)
> Carbon Dioxide (0.03%)
> Argon and remaining other gases.
The density, Pressure, and Temperature of the gases decrease as we go up in the atmosphere.
Importance of Carbon Dioxide
Carbon dioxide, though present in very small but it is very important as it absorbs heat radiated by the earth and keeps it warm. It is also
essential for the growth of plants.
An increase in the amount of CO2 leads to an increase in global temperatures. This is called global warming.