Oceans major

Residue Disposal. The major environmental problem in the Bayer process is disposal of bauxite residue which is effected by marine disposal, lagooning, use of underdrain lakes, or semidry disposal. Marine disposal in oceans or rivers, diluting the alkaline residue by large quantities of water, is environmentally unacceptable. Lagooning behind retaining dikes built around clay-sealed ground is commonly used, but there have been isolated leaks into aquifers. This has motivated installation of underdrains between the residue and clay-sealed, plastic-lined, lake bottom. This design removes the hydraulic head from the lake bottom and improves consoHdation of the residue. 

Chlorine. Nearly all chlorine compounds are readily soluble in water. As a result, the major reservoir for this element in Figure 1 is the ocean (5). Chloride, as noted earHer, is naturally present at low levels in rain and snow, especially over and near the oceans. Widespread increases in chloride concentration in mnoff in much of the United States can be attributed to the extensive use of sodium chloride and calcium chloride for deicing of streets and highways. Ref. 19 points out the importance of the increased use of deicing salt as a cause of increased chloride concentrations in streams of the northeastern United States and the role of this factor in the chloride trends in Lake Ontario. Increases in chloride concentration also can occur as a result of disposal of sewage, oil field brines, and various kinds of industrial waste. Thus, chloride concentration trends also can be considered as an index of the alternation of streamwater chemistry by human development in the industrialized sections of the world. Although chlorine is an essential element for animal nutrition, it is of less importance for other life forms. 

The basic reason for the ocean being a major sink for COj lies in the reaction of the gas with water, and subsequent anion breakdown ... 

The majority of published °Pb reports address the utility of °Pb as a geochronological tool rather than as an element that is involved in complex biogeochemical cycles. Nonetheless, some of these studies do provide insight into the geochemical behavior of °Pb and °Po. Nearly all of the lead in the world s surface oceans is believed to be of anthropogenic origin—derived from combustion... 

The outer shell of the earth, consisting of the upper mantle and the crust (Figure I4. lO), is formed of a number of rigid plates. These plates are 20 in number and are shown in Figure 14.1 I. Of these, six or seven are major plates, as can be seen in the map. The edges of these plates define their boundaries and the arrows indicate the direction of their movement. These plates contain the continents, oceans and mountains. They almost float on the partially molten rock and metal of the mantle. The outer shell, known as the lithosphere, is about 70 to 1,50 km thick. It has already moved great distances below the etirth s surface, ever since the earth was formed and is believed to be in slow and continuous motion all the time. The plates slide on the molten mantle and move about lO to 100 mm a year in the direction shown by the arrows. The movement of plates is believed to be the cause of continental drifts, the formation of ocean basins and mountains and also the consequent earthquakes and volcanic eruptions. 

Oil Spills. Oil spills occur from oil pipeline leaks, oil tanker accidents, or submarine oil drilling operations. The two major ocean drilling accidents—oil wells blowing out—were the 1969 Santa Barbara Channel spill and the 1979 Yucatan Peninsula spill, in Mexico. The Yucatan spill spewed out more than three million barrels before being capped in 1980. Both caused damage to beaches and marine life, but the smaller Santa Barbara spill was far more devastating because of unfavorable winds following the accident. 

Another major function of the DOC is the management of energy-related research through the National Institute of Standards and Technologies Laboratories in Gaithersburg, Mainland and Boulder, Colorado and the research laboratories of the National Oceanic and Atmospheric Administration. 

Ocean sea water is roughly equivalent in strength to a 3 j % w/v solution of sodium chloride, but it has a much more complex composition, embodying a number of major constituents, and traces at least of almost all naturally occurring elements. For convenience, however, the concentration of salts in any sample of sea water is expressed in terms of the chloride content, either as chlorinity or as salinity. Both these units are again subject to arbitrary definition and do not conform simply to the chemical composition. 

Variations of salinity In the major oceans the salinity of sea water does not vary widely, lying in general between 33 and 37 parts per thousand, a figure of 35 parts per thousand, equivalent to 19-4 parts per thousand chlorinity is commonly taken as the average for open-sea water. 

One of the major problems facing our civilization is the availability of pure water. The largest source of water located near many cities is the ocean, but the ocean is filled with large amounts of dissolved salts. To recover water from the sea by any of the conventional distillation processes is to date extremely wasteful of energy and costly. However in... 

A circumnavigation of the world s oceans between 1978-1980 (18), further indicated that broad expanses of the Atlantic, Pacific, and Indian Oceans away from major tanker lanes and shipping routes contained little or no tar, whereas tar pollution was prevalent in the Mediterranean, Java Sea and Red Sea, and in western European and Northwest African coastal areas. 

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