Hydrosphere and Atmosphere

Hydrosphere

The Hydrosphere is made up of all those areas on the surface of earth that are covered in water or ice. Oceans and seas, rivers and lakes, glaciers and underground water, even the water vapor in the atmosphere, all of these constitute the hydrosphere. It covers almost 70% of the earth’s surface. Only 30% is land, or Lithosphere. The rivers and lakes contain Fresh Water while the oceans and seas contain Salt Water.

The hydrosphere is essential for life on earth. It provides water for animals and plants, it wears away rocks to make soil, it controls the earth’s weather and climate.

Constituents of the atmosphere

The Water Cycle

The elements of the hydrosphere are constantly in motion. Water is continuously moving from oceans to air, to land, and back to the oceans. This Water Cycle is driven by the sun. The sun evaporates the water from the oceans, making it rise in the form of water vapor into the atmosphere. The vapor forms clouds which Precipitate to fall back to earth in the form of rain or snow or hail or sleet or some other form of moisture. This distribution and circulation of water ensures that we always have enough water on the planet at all times.

The water cycle does the following –

1. It fills all the water bodies – oceans, lakes, rivers
2. On land, it seeps into the ground to create Ground Water supply, which runs off to fill the rivers and eventually the seas
3. In mountainous areas it forms snow, ice and glaciers, which melt in warm weather to fill rivers and seas