What is the Hydrosphere?
The hydrosphere refers to all water found on, under, or over the surface of a planet. In physical geography, it usually refers to the hydrosphere of the planet Earth, although the Jovian moon Europa is thought to have a subsurface ocean. Sometimes the hydrosphere is inclusive of the cryosphere, or all ice on the surface, in which case that would include Mars, which has ice caps. About 70.8% of the Earth’s surface is covered by water. 97% of the Earth’s surface is sea water while 3% is fresh water. Water can also be found in significant portions in the atmosphere, which is thought to consist of about 1% water vapor. The oceans, with an average depth of 3,794 m (12,447 ft) (five times deeper than the average height of the continents), are thought to have a total weight of about 1.35 × 1018 tonnes, or about 1/4400 of Earth’s total mass. The Earth’s life (biosphere) is heavily interdependent on the hydrosphere. Where there is little water, only certain extremophile microbes can survive. Wh
The hydrosphere is the liquid water component of the Earth. It includes the oceans, seas, lakes, ponds, rivers and streams. The hydrosphere covers about 70% of the surface of the Earth and is the home for many plants and animals. (U.S. Fish and Wildlife Service/Craig Blacklock) The hydrosphere, like the atmosphere, is always in motion. The motion of rivers and streams can be easily seen, while the motion of the water within lakes and ponds is less obvious. Some of the motion of the oceans and seas can be easily seen while the large scale motions that move water great distances such as between the tropics and poles or between continents are more difficult to see. These types of motions are in the form of currents that move the warm waters in the tropics toward the poles, and colder water from the polar regions toward the tropics. These currents exist on the surface of the ocean and at great depths in the ocean (up to about 4km). (NOAA Photo Collection/Commander John Bortniak, NOAA Corps
