|
|
DIFFERENT

Water
is a common chemical substance that is essential to all known forms of
life. In typical usage, water refers only to its liquid form or state,
but the substance also has a solid state, ice, and a gaseous state, water
vapor. About 1,460 teratonnes (Tt) of water covers 71% of the Earth's
surface, mostly in oceans and other large water bodies, with 1.6% of water
below ground in aquifers and 0.001% in the air as vapor, clouds (formed
of solid and liquid water particles suspended in air), and precipitation.
Some of the Earth's water is contained within man-made and natural objects
near the Earth's surface such as water towers, animal and plant bodies,
manufactured products, and food stores.Saltwater oceans
hold 97% of surface water, glaciers and polar ice caps 2.4%, and other
land surface water such as rivers and lakes 0.6%. Water moves continually
through a cycle of evaporation or transpiration (evapotranspiration),
precipitation, and runoff, usually reaching the sea. Winds carry water
vapor over land at the same rate as runoff into the sea, about 36 Tt per
year.
|
|