Chlorine concentration ocean

Recently Sharp et al. (2007) have questioned the findings of Magenheim et al. (1995). Sharp et al. (2007) found that the large differences between mantle and crustal material do not exist and that the mantle and the crust have very similar isotopic composition. A possible explanation for this apparent discrepancy might be related to analytical artifacts of the TIMS technique (Sharp et al. 2007). Bonifacie et al. (2008) also observed small Cl-isotope variations only in mantle derived rocks. They demonstrated that 5 Cl values correlate with chlorine concentrations Cl-poor basalts have low S Cl values and represent the composition of uncontaminated mantle derived magmas, whereas Cl-rich basalts are enriched in Cl and are contaminated by Cl-rich material such as ocean water. 

Wingenter O. W., Blake D. R., Blake N. J., Sive B. C., Rowland F. S., Atlas E., and Flocke F. (1999) Tropospheric hydroxyl and atomic chlorine concentrations, and mixing timescales determined from hydrocarbon and halocarbon measurements made over the Southern Ocean. J. Geophys. Res. 104, 21819-21828. 

Wingenter, O.W, B.C. Sive, N.J. Blake, D.R. Blake, and F.S. Rowland (2005), Atomic chlorine concentrations derived from ethane and hydroxyl measurements over the equatorial Pacihc Ocean Imphcation for dimethyl sulHde and bromine monoxide, J. Geophys. Res., 110, D20308. 

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. 

Chlorine is the twentieth most abundant element in crustal rocks where it occurs to the extent of 126 ppm (cf. nineteenth V, 136 ppm, and twenty-first Cr, 122 ppm). The vast evaporite deposits of NaCl and other chloride minerals have already been described (pp. 69, 73). Dwarfing these, however, are the inconceivably vast reserves in ocean waters (p. 69) where more than half the total average salinity of 3.4 wt% is due to chloride ions (1.9 wt%). Smaller quantities, though at higher concentrations, occur in certain inland seas and in subterranean brine wells, e.g. the Great Salt Lake, Utah (23% NaCl) and the Dead Sea, Israel (8.0% NaCl, 13.0% MgCU, 3.5% CaCU). 

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. 

SauerTC Jr, Durell GS, Brown JS, et al. 1989. Concentrations of chlorinated pesticides and PCBs in microlayer and seawater samples collected in open-ocean waters off the U.S. East Coast and in the Gulf of Mexico. Mar Chem 27 235-257. 

Concentrated chlorine gas and many chlorine compounds will oxidize powdered metals, hydrogen, and numerous organic materials and release enough heat to generate fires or explosions. Chlorine is constantly evaporating from the oceans and drifting into the atmosphere where it causes a natural depletion of the ozone. 

Culkin F. and Smith N. D. (1980) Determination of the concentration of potassium chloride solution having the same electrical conductivity at 15 °C and infinite frequency as standard seawater of salinity 35.000% (Chlorinity 19.37394). lEEEJ. Ocean. Eng. OE-5, 22-23. 

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