hydrosphere is the combined name (for the study purpose) given to all the water bodies found on the earth’s surface, for example, oceans, rivers, lakes, etc.
about 71% of the earth’s surface is covered by water and rest is covered by landmass.
about 97.5% (of total hydrosphere) is saline water and rest 2.5% is fresh water.
about 68.7% of the fresh water is available in the form of permanent snow found in the regions of arctic, antarctic, and other mountain glaciers.
about 29.9% fresh water is available in the form of (fresh) groundwater.
only about 0.26% fresh water is easily accessible for the use, available in the form of rivers, lakes, reservoirs, etc.
oceans
there are five oceans namely −
pacific ocean
atlantic ocean
indian ocean
arctic ocean &
southern ocean
the following table describes the major facts of all the five oceans −
| ocean | area (sq. km) | % of total | avg. depth (in meter) | deepest point |
|---|---|---|---|---|
| pacific ocean | 168,723,000 | 46.6 | 3,970 | mariana trench (10,994 m deep) |
| atlantic ocean | 85,133,000 | 23.5 | 3,646 | puerto rico trench (8,648 m) |
| indian ocean | 70,560,000 | 19.5 | 3,741 | diamantina trench (8,047 m) sunda trench (7,725 m) |
| arctic ocean | 15,558,000 | 15,558,000 | 1,205 | eurasian basin (5,450 m) |
| southern ocean | 21,960,000 | 6.1 | 3,270 | south sandwich trench (7,236 m) |