HYDROSPHERE
The earth is called the blue planet. More than 71 percent of the earth is covered with water and 29 percent is with the land. Hydrosphere consists of water in all its forms. As running water in oceans and rivers and in lakes, ice in glaciers, underground water, and the water vapor in the atmosphere, all comprise the hydrosphere.
More than 97% of the Earth’s water is found in the oceans and is too salty for human use. A large proportion of the rest of the water is in the form of ice sheets and glaciers or under the ground and a very small percentage is available as freshwater for human use. Hence, despite being a ‘blue planet’ we face a shortage of water!!
Source: This Topic is taken from NCERT TEXTBOOK
OCEAN
Oceans are a major part of the hydrosphere. They are all interconnected. The ocean waters are always moving. The three chief movements of ocean waters are the waves, the tides, and the ocean currents. The five major oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean, in order of their size (Figure 5.1).
The Pacific Ocean is the largest ocean. It is spread over one-third of the earth. Mariana Trench, the deepest part of the earth, lies in the Pacific Ocean. The Pacific Ocean is almost circular in shape. Asia, Australia, North, and South America surround it. Look at the map and find out the location of the continents around the Pacific Ocean.
The Atlantic Ocean is the second-largest ocean in the world. It is ‘S’ shaped. It is flanked by the North and South Americas on the western side, and Europe and Africa on the eastern side. The coastline of the Atlantic Ocean is highly indented. This irregular and indented coastline provide an ideal location for natural harbors and ports. From the point of view of commerce, it is the busiest Ocean.
The Indian Ocean is the only ocean named after a country, that is, India. The shape of the ocean is almost triangular. In the north, it is bound by Asia, in the west by Africa, and in the east by Australia.
The Southern Ocean encircles the continent of Antarctica and extends northward to 60 degrees south latitude.
The Arctic Ocean is located within the Arctic Circle and surrounds the North Pole. It is connected with the Pacific Ocean by a narrow stretch of shallow water known as Berring strait. It is bound by the northern coasts of North America and Eurasia.
Source: This Topic is taken from NCERT TEXTBOOK