Related topics: climate change , rivers , ice , soil , hydrogen
Water
hideWater is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many 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 or steam. Water covers 71% of the Earth's surface. On Earth, it is found 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. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.
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. Over land, evaporation and transpiration contribute to the precipitation over land.
Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.
For more information about Water, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with water
Light-Driven Nanorod Could Roll on Water
Dec 18, 2009 |
4 / 5 (9) |
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(PhysOrg.com) -- In a recent study, researchers have examined the possibility of rolling a nanorod on the surface of water. On the macroscale, perhaps the closest analogy might be the sport of logrolling, ...
Water droplets shape graphene nanostructures
Dec 17, 2009 |
4.6 / 5 (7) |
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A single-atom-thick sheet of carbon, like those seen in pencil marks -- offers great potential for new types of nanoscale devices, if a good way can be found to mold the material into desired shapes.
Study sheds light on microscopic flower petal ridges
10 hours ago |
4 / 5 (2) |
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(PhysOrg.com) -- Microscopic ridges contouring the surface of flower petals might play a role in flashing that come-hither look pollinating insects can't resist. Michigan State University scientists and colleagues ...
Global warming likely to be amplified by slow changes to Earth systems
Space & Earth / Earth Sciences
Dec 20, 2009 |
2.6 / 5 (38) |
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Researchers studying a period of high carbon dioxide levels and warm climate several million years ago have concluded that slow changes such as melting ice sheets amplified the initial warming caused by greenhouse ...
How water forms where Earth-like planets are born
Dec 17, 2009 |
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(PhysOrg.com) -- In a study that helps to explain the origins of water on Earth, University of Michigan astronomers have found that water vapor can form spontaneously in habitable zones of solar systems, and that it develops ...
Chemistry makes the natural 'wonder fabric' -- wool -- more wonderful
Nanotechnology / Nanomaterials
15 hours ago |
not rated yet |
0
Scientists in China are reporting an advance that may improve the natural wonders of wool — already regarded as the "wonder fabric" for its lightness, softness, warmth even when wet, and other qualities. They ...
Mexico's conch shells yield clues into effects of warming
18 hours ago |
3 / 5 (1) |
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Divers plumb the turquoise depths of ocean waters some 100 kilometers south of this vacation paradise, in search of the distinctive queen conch shell prized by vacationers and souvenir-seekers.
Graphite oxide at high pressure opens a road to new amazing nano-materials
Nanotechnology / Nanomaterials
Dec 21, 2009 |
5 / 5 (2) |
1
(PhysOrg.com) -- New results by scientists at Umeľ University, Sweden, show that not only water but also alcohol solvents can be inserted to expand the structure of graphite oxide under high pressure conditions. The ...
Study on Great Lakes erosion dredges up controversy
Dec 17, 2009 |
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The Great Lakes aren't as great as they once were. A U.S.-Canadian study released Tuesday reveals that unexpected erosion in the St. Clair River following a 1962 dredging project has permanently lowered Lakes Michigan and ...
Lost water of the Napa Valley vineyards
Space & Earth / Earth Sciences
Dec 16, 2009 |
4.3 / 5 (3) |
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Getting the most out of every drop of water is a high priority for grape growers in the southern Napa Valley, where summers are hot and dry and vines have to be irrigated to make it through the growing season. But Stanford ...
New research may help to clean drainage from abandoned mines
Dec 16, 2009 |
4.8 / 5 (4) |
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(PhysOrg.com) -- In a quiet green glen near Ashville, Pa., lies a rust-colored pond. A deep, rectangular hole in the ground, it somewhat resembles an Olympic-sized pool. Few people, however, would make the ...
Feds mull regulating drugs in water
12 hours ago |
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(AP) -- Federal regulators under President Barack Obama have sharply shifted course on long-standing policy toward pharmaceutical residues in the nation's drinking water, taking a critical first step toward regulating some ...
