Major Domains of Earth: Hydrosphere

Availability of water on Earth
Five Oceans

All the water present on the earth makes the hydrosphere.

More than 71% of the earth’s surface is covered with water. But 97% of the total water on earth is available as saline water in oceans and seas. Saline water is not fit for human consumption.

Out of the remaining 3% water; most of the water is in the form of ice in glaciers and icebergs. This leaves less than 1% of total water on earth available for human consumption. Hence, in spite of living on the Blue Planet we often face scarcity of water.

Oceans

The large continuous body of saline water is called ocean.

All oceans are interconnected and water in the oceans is always on move. Waves, tides and ocean currents are the three main movements of ocean water. There are five major oceans, viz. Pacific, Atlantic, Indian, Arctic and Southern oceans.

Image Ref: Encyclopaedia Brittanica

Pacific Ocean

This is the largest ocean. It is almost circular in shape. The Pacific Ocean is surrounded by Asia, Australia, North America and South America. Mariana Trench; the deepest place on the earth is in this ocean.

Atlantic Ocean

This is the second largest ocean. It is S-shaped. North America and South America are to the west of this ocean. Europe and Africa are on the east of this ocean. The coastline of this ocean is highly indented. The irregular and indented coastline provides ideal place for natural harbours and ports. Hence, this is the busiest ocean from commercial perspective.

Indian Ocean

Indian Ocean is the only ocean to be named after a country. This ocean is almost triangular in shape. Asia is towards north, Africa is towards west and Australia is towards east of this ocean.

Southern Ocean

This ocean encircles Antarctica. It extends northwards up to 60^oS latitude.

Arctic Ocean

This ocean is within the Arctic Circle. It surrounds the North Pole. It is bound by the northern coasts of North America and Eurasia. The Arctic Ocean is connected to the Pacific Ocean by a narrow stretch of water called Berring Strait.