Water on earth

Human Appropriation of Renewable Freshwater. Freshwater constitutes about 2.5% of the total volume of water on earth and two-thirds of this freshwater is locked in glaciers and ice caps. 

Ear from being just the processing of water on Earth, this cycle is the basis for a wide range of meteorologic, geochemical, and biological systems. Water is the transport medium for all nutrients in the biosphere. Water vapor condensed into clouds is the chief control on planetary albedo. The cycling of water is also one of the major mechanisms for the transportation of sensible heat (e.g. in oceanic circulation) and latent heat that is released when water falls from the air. 

The major reservoirs of water on Earth are the oceans. The hydrologic cycle is driven primarily by evaporation of water from the oceans, lakes. 

Fig. 2.7 The distribution of the ratio of the two hydrogen isotopes (D/H) in carbonaceous meteorites compared with that on Earth and in the comets. According to this distribution, most of the water on Earth must have had its origin in meteorites. From Robert (2001)...

The landlocked Caspian Sea is the largest inland body of water on Earth. Surrounded by Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan, the Caspian Sea is home to myriad ecosystems. At the meeting point of the Middle East, Europe, and Asia, the Caspian region includes steppe land in the north, cold, continental deserts and semi-deserts in the northeast and east, and warmer mountain and highland systems in the south and southwest. The coastal wetlands of the Caspian basin include many shallow, saline pools, which attract a variety of bird life and biodiversity over 400 species are unique to the Caspian. In addition, the sea s native sturgeon is famous the world around for the roe it produces sturgeon from the Caspian Sea accounts for approximately 90% of the world s caviar industry. 

Most of the water on Earth s surfece is in the ocean relatively little is present in the atmosphere or on land. Because of its chemical and physical properties, this water has had a great influence on the continuing biogeochemical evolution of our planet. Most notably, water is an excellent solvent. As such, the oceans contain at least a little bit of almost every substance present on this planet. Reaction probability is enhanced if the reactants are in dissolved fitrm as compared with their gaseous or solid phases. Many of the chemical changes that occur in seawater and the sediments are mediated by marine organisms. In some cases, marine organisms have developed unique biosynthetic pathways to help them survive the environmental conditions fitimd only in the oceans. Some of their metabolic products have proven useful to humans as pharmaceuticals, nutraceuticals, food additives, and cosmeceuticals. 

As shown in Figure 2.1, the free water on Earth s surface is now transported between the land, atmosphere, ocean, and mantle through a global hydrological cycle. From... 

The global heat cycle drives the hydrological cycle, which in turn controls the salinity of seawater. The most important contributor of heat to the crustal-ocean-fectory is solar radiation. The flux of solar radiation that reaches Earth is termed insolation. Only a fraction of the incoming solar radiation reaches Earth s surfece, because a large portion is either reflected or absorbed by the atmosphere. That which reaches Earth s surface is also either reflected or absorbed. In the end, about half of the incoming radiation is absorbed by the rocks and water on Earth s surfece. (A detailed heat budget is provided... 

D/H ratios in carbonaceons chondrites may hint on the origin of water on Earth. Robert (2001) suggested that since the contribntion of cometary water to terrestrial water should be less than 10%, most of the water on Earth should derive from a meteoritic source. 

Ripley EM, Li C (2003) Sulfur isotope exchange and metal enrichment in the formation of magmatic Cu-Ni-(PGE)-deposits. Econ Geol 98 635-641 Robert F (2001) The origin of water on Earth. Science 293 1056-1058... 

Water is among the most important compounds on earth. It is the main constituent of the hydrosphere, which along with the mantle, crust, and the atmosphere are the four components of our planet. It is present everywhere on earth and is essential for sustenance of life. Water also determines climate, weather pattern, and energy balance on earth. It also is one of the most abundant compounds. The mass of all water on earth is l.dxlO i kg and the total volume is about l.dxlO km, which includes 97.20% of salt water of oceans, 2.15% of fresh water in polar ice caps and glaciers, 0.009% in freshwater lakes, 0.008% in saline lakes, 0.62% as ground waters, 0.005% in soil moisture 0.0001% in stream channels and 0.001% as vapors and moisture in the atmosphere. 

Unfortunately, despite the fact that most of the planet is covered by water, only a small amount of this water is available as fresh water. Almost 97.5% of the total is in oceans in the form of salty water and is not suitable for drinking, watering, or industrial use as is. The remaining 2.5% is fresh water. However, not even that small amount is easily accessible or exploited, because it is stored as ice on the poles and on mountaintops. Furthermore, a significant amount of the rest lies so deep in the ground that it is very difficult to extract. In Figure 1.3, the distribution of water on Earth is presented. According... 

If you have ever stood on the shore of one of the Great Lakes or experienced the power of a waterfall or been caught in a rainstorm, it may seem to you that the supply of fresh water on Earth is inexhaustible. From the perspective of one person, it is. Our population, however, has grown to more than 6 billion people. If we were to spread ourselves evenly across all habitable lands, there would be about 50 of us in every square kilometer. Thus it should come as no surprise that collectively we have a significant impact on Earth s relatively limited resources, such as fresh water. 

In contemplating the possible use of icebergs as a future source of fresh water, it is interesting to note that although there are about 1.4 billion cubic kilometers of water on Earth, only about 9 million cubic kilometers (six-tenths of one per cent) of the total is both liquid and fresh. The useful supply tends to be about 10-20% of the total precipitation per year, or about 10,000-20,000 cubic kilometers. 

As seawater is the most available water on earth, the possibility of application of sonophotocatalytic reaction system to seawater cleavage is also examined. It is known that sodium chloride (NaCl) is the principal mineral constituent of seawater and chloride ion (Cl ) concentration is nearly 2%.29) When the desired amount of NaCl is added into the system, effects of NaCl on the reaction of each process are assumed to occur. 

Our view of water on earth was incorrect until our journey into space. Our journey into space gave us the correct view of water on earth. 

The water on earth (above the surface, under the surface as well as in the oceans) is called the hydrosphere. 

Water is not distributed evenly over the surface of the earth. The total amount of water on land is 2.7% of the total water on earth (7.3% of the total area) Of this 2.7%... 

If all the water on earth is evenly spread on the surface of the earth, it will cover the entire earth to a depth of 3.2 kms ... 

Water exists as water, ice and water vapour at the same time only on our planet. It has the unique ability to change from solid to liquid, liquid to solid, liquid to gas or gas to liquid. This unique property of water is responsible for the amount of water on earth not diminishing significantly. 

The water vapour content in the atmosphere is only 0.001% of the total volume of water on earth. This minute amount is responsible for all the forms of precipitation. If we condense this amount of water vapour and uniformly spread it over the earth, it would form a 2.5 cm thick layer The content of water vapour in the atmosphere is not uniform. It varies from place to place. It also decreases with increase in the height of the atmosphere. 

This is the final leg of the never ending journey of water on earth. Not all the clouds are part of the precipitation process. When the condensed water droplets... 

Melting is the process by which a solid changes into a liquid, and is the phase change that allows frozen water on Earth to be taken out of storage. In this case, a stored water particle is one that stays... 

One of the great virtues of the FREZCHEM model is its ability to examine complex chemistries. The number of independent components for the systems examined in this chapter range from four to eight. Earth seawater consisting of Na+, K+, Mg2+, Ca2+, Cl-, SO4-, and alkalinity has seven independent components (six salts and water). The most complex system evaluated is the snowball Earth seawater (eight independent components), which in addition to the above seven components also includes Fe2+. This ability to cope with complexity makes models like FREZCHEM more realistic in describing natural systems than simpler binary and ternary diagrams we demonstrate this point with data from Don Juan Pond, the most saline body of water on Earth. 

Q O Write a brief report that lists the different methods used to clean water on Earth. Explain how each method works. Remember to include diagrams and any relevant balanced chemical equations. 

Surface water is that contained in streams, rivers, ponds, lakes, swamps, marshes, and springs. Approximately 0.014% of the water on Earth is found on continental land, while the rest is contained in the oceans and ice caps, glaciers, permanent snow, groundwater, and as water vapor in the atmosphere. 

Approximately0.007% of the total water on Earth is contained in freshwater lakes, 0.006% in saline lakes, 0.002% in rivers, and 0.0008% forms part of swamp water. The rest of the surface water (approximately 0.0011%) is present as soil moisture or as a part of biological matter (see Figure 6.1). 

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