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
LCROSS Impact Finds Water on the Moon
Space & Earth / Space Exploration
Nov 13, 2009 |
4.9 / 5 (31) |
15
(PhysOrg.com) -- The argument that the moon is a dry, desolate place no longer holds water. Secrets the moon has been holding, for perhaps billions of years, are now being revealed to the delight of scientists ...
H1N1 Virus Can Be Killed by Acidic Ozone Water
Nov 09, 2009 |
4.5 / 5 (44) |
16
(PhysOrg.com) -- Scientists have found that acidic ozone water can deactivate H1N1 viruses very effectively, offering a promising disinfectant for the millions of people trying to avoid the disease. Acidic ...
Renewable Energy Made by Mixing Salt and Fresh Water
Sep 02, 2009 |
4.3 / 5 (27) |
6
(PhysOrg.com) -- When a river flows into the sea, the location is more than just a haven for water commerce. The mixing of fresh and salt water that occurs at an estuary also dissipates energy, as the different ...
Japanese researchers film rare baby fish 'fossil'
Nov 17, 2009 |
4.7 / 5 (7) |
4
Japanese marine researchers said Tuesday they had found and successfully filmed a young coelacanth -- a rare type of fish known as "a living fossil" -- in deep water off Indonesia.
Scientists pinpoint origin of dissolved arsenic in Bangladesh drinking water
Nov 15, 2009 |
4.8 / 5 (21) |
1
Researchers in MIT's Department of Civil and Environmental Engineering believe they have pinpointed a pathway by which arsenic may be contaminating the drinking water in Bangladesh, a phenomenon that has puzzled ...
New explanation for nature's hardiest life form
Nov 12, 2009 |
4.3 / 5 (8) |
0
Got food poisoning? The cause might be bacterial spores, en extremely hardy survival form of bacteria, a nightmare for health care and the food industry and an enigma for scientists. Spore-forming bacteria, present almost ...
Earth's early ocean cooled more than a billion years earlier than thought (w/ Video)
Space & Earth / Earth Sciences
Nov 11, 2009 |
4.3 / 5 (12) |
1
(PhysOrg.com) -- The scalding-hot sea that supposedly covered the early Earth may in fact never have existed, according to a new study by Stanford University researchers who analyzed isotope ratios in 3.4 ...
Mom was right: Why nice guys usually get the girls
Nov 05, 2009 |
4.6 / 5 (9) |
1
(PhysOrg.com) -- Female water striders often reject their most persistent and aggressive suitors and prefer the males who aren't so grabby, according to new research. Water striders are insects commonly seen ...
Metal-Air Battery Could Store 11 Times More Energy than Lithium-Ion
Nov 05, 2009 |
4.4 / 5 (49) |
12
(PhysOrg.com) -- A spinoff company from Arizona State University plans to build a new battery with an energy density 11 times greater than that of lithium-ion batteries for just one-third the cost. With a ...
Jupiter's Moon Europa Has Enough Oxygen For Life
Space & Earth / Earth Sciences
Oct 16, 2009 |
4.8 / 5 (94) |
42
New research suggests that there is plenty of oxygen available in the subsurface ocean of Europa to support oxygen-based metabolic processes for life similar to that on Earth. In fact, there may be enough ...
Scientists discover protein receptor for carbonation taste
Oct 15, 2009 |
4.5 / 5 (4) |
0
(PhysOrg.com) -- In 1767, chemist Joseph Priestley stood in his laboratory one day with an idea to help English mariners stay healthy on long ocean voyages. He infused water with carbon dioxide to create an effervescent ...
Water Bears to Travel to Martian Moon, Test Theory of Transpermia
Space & Earth / Space Exploration
Oct 13, 2009 |
3.9 / 5 (14) |
22
(PhysOrg.com) -- Tiny microscopic creatures commonly known as water bears (also called Tardigrades), along with a few other life forms, will be sent to the Martian moon Phobos to test whether organisms can ...
Researchers go underground to reveal 850 new species
Sep 28, 2009 |
4.6 / 5 (5) |
0
Australian researchers have discovered a huge number of new species of invertebrate animals living in underground water, caves and "micro-caverns" amid the harsh conditions of the Australian outback.
Scientists see water ice in fresh meteorite craters on Mars
Space & Earth / Space Exploration
Sep 24, 2009 |
4.8 / 5 (16) |
3
(PhysOrg.com) -- Scientists are seeing sub-surface water ice that may be 99 percent pure halfway between the north pole and the equator on Mars, thanks to quick-turnaround observations from orbit of fresh ...
Mice Levitated for Space Research
Sep 11, 2009 |
4.1 / 5 (11) |
21
(PhysOrg.com) -- Scientists have managed to levitate young mice in research carried out for NASA. Levitated mice may help research on bone density loss during long exposures to low gravity, such as in space ...
