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2. hyDroSPhere

The domain of water on the earth’s surface is called hydrosphere. Water bodies cover
about 71% of total area of the earth. Water is found in oceans, seas, rivers, lakes, ponds,
etc. Oceans and seas have about 97% of total water present on the earth, but it is useless
for human consumption because it is salty.

Continents and Oceans of the world

• The earth looks blue from space due to presence of too much water on it so it is also called blue
planet.
• A large part of the fresh water is in the form of glaciers and ice. Only a very small (0.03 %)
amount of water is available for human beings and animals.
• The Arctic ocean is connected with the pacific ocean by a narrow stretch of shallow water known
as Berring Strait.
• Australia, New Zealand and other nearby islands together are called Australasia.

imPortanCe of oCeanS

• They maintain the temperature of the earth.

• They provide a very good transport route and link many countries.
• They are source of mineral oil.
• They are home of aquatic animals.

• Their water is used to make salt.
There are four major oceans:

1. The Pacific Ocean 2. The Atlantic Ocean
3. The Indian Ocean 4. The Arctic Ocean

1. The PaCifiC oCean :

It is the largest ocean. It is spread over one-third of the earth. Mariana Trench, the deepest
part of the earth lies under the Pacific ocean. The Pacific Ocean is circular in shape. Asia,
Australia, North and South America surround it.

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