What is hydrosphere?

The hydrosphere is the combined mass of water found on, under, and above the surface of the earth. It has been estimated that there are 1386 million cubic kilometres of water on earth. This includes water in liquid and frozen forms in ground water, oceans, lakes and streams.pproximately 75% of Earth’s surface, an area of some 361 million square kilometers is covered by ocean.

Hydrological cycle

The hydrological cycle transfers water from one state or reservoir to another. Reservoirs include atmospheric moisture including snow, rain and clouds, streams, oceans, rivers lakes, groundwater, subterranean aquifers, polar icecaps and saturated soil.


Solar energy is the source of heat and light and gravity causes the transfer from one state to another over periods from hours to thousands of years. Most evaporation comes from the oceans and is returned to the earth as snow or rain.

Importance of Hydrosphere

It consists of all bodies of water, icebergs and water vapor in the earth’s atmosphere. Oceans contain 97 percent of water in the hydrosphere, while rivers, lakes and other water bodies on land and underground water contains a small percentage of total water in the hydrosphere.

Here are the importance of the layer-

  • Helps to maintain the hydrological cycle.
  • Good means of transport of water
  • Plays a vital role in the earth’s climate.

Practise This Question

If the power of two lenses and P1 and P2; when they are combined; the effective power is: