Ocean chemistry

Total Molar Composition of Seawater (Salinity = 35)[1]
Component Concentration (mol/kg)
H
2
O
53.6
Cl
0.546
Na+
0.469
Mg2+
0.0528
SO2−
4
0.0282
Ca2+
0.0103
K+
0.0102
CT 0.00206
Br
0.000844
BT (total boron) 0.000416
Sr2+
0.000091
F
0.000068

Ocean chemistry, also known as marine chemistry, is influenced by turbidity currents, sediments, pH levels, atmospheric constituents, metamorphic activity, and ecology. The field of chemical oceanography studies the chemistry of marine environments including the influences of different variables.

Marine chemistry on earth

Organic compounds in the oceans

Coloured dissolved organic matter is estimated to range 20-70% of carbon content of the oceans, being higher near river outlets and lower in the open ocean.[2]

Marine life is largely similar in biochemistry to terrestrial organisms, except that they inhabit a saline environment. One consequence of their adaptation is that marine organisms are the most prolific source of halogenated organic compounds.[3]

Chemical ecology of extremophiles

The ocean provides special marine environments inhabited by extremophiles that thrive under unusual conditions of temperature, pressure, and darkness. Such environments include black smokers and cold seeps on the ocean floor, with entire ecosystems of organisms that have a symbiotic relationship with bacteria and hydrocarbon compounds that provided energy through a process called chemosynthesis.

A diagram showing ocean chemistry around deep sea vents

Climate change

Increased carbon dioxide levels, resulting from anthropogenic factors or otherwise, have the potential to impact ocean chemistry. Global warming and changes in salinity have significant implications for ecology of marine environments.[4] One proposal suggests dumping massive amounts of lime, a base, to reverse the acidification and "increase the sea's ability to absorb carbon dioxide from the atmosphere".[5][6][7]

Marine chemistry on other planets and their moons

A planetary scientist using data from the Cassini spacecraft has been researching the marine chemistry of Saturn's moon Enceladus using geochemical models to look at changes through time.[8] The presence of salts may indicate a liquid ocean within the moon, raising the possibility of the existence of life, "or at least for the chemical precursors for organic life".[8][9]

References

  1. DOE (1994). A.G. Dickson & C. Goyet, eds. "Handbook of methods for the analysis of the various parameters of the carbon dioxide system in sea water" (PDF). 2. ORNL/CDIAC-74. |chapter= ignored (help)
  2. Coble, Paula G. (2007). "Marine Optical Biogeochemistry:  The Chemistry of Ocean Color". Chemical Reviews 107: 402–418. doi:10.1021/cr050350.
  3. Gribble, Gordon W. (2004). "Natural Organohalogens: A New Frontier for Medicinal Agents?". Journal of Chemical Education 81: 1441. doi:10.1021/ed081p1441.
  4. Millero, Frank J. (2007). "The Marine Inorganic Carbon Cycle". Chemical Reviews 107: 308–341. doi:10.1021/cr0503557.
  5. Duncan Clark Cquestrate: adding lime to the oceans; Putting lime into the oceans has the potential to decrease ocean acidity and reduce atmospheric CO2 levels 13 July 2009 The Guardian (UK)
  6. Ian Katz 20 ideas that could save the world; Dump Billions of Tons of Limestone Into 13 July 2009 The Guardian (UK)
  7. http://www.infrastructurist.com/2009/07/14/from-the-uk-20-bold-schemes-that-could-save-us-from-global-warming/ July 14, 2009 Infrastructurist
  8. 1 2 Pete Spotts Cassini spacecraft finds evidence for liquid water on Enceladus June 25, 2009 Christian Science Monitor
  9. Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus Nature 459, 1098-1101 (25 June 2009) Nature

External links

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