Canfield ocean

The Canfield Ocean model refers to the Ocean composition theorized by geologist Donald Canfield. In a seminal paper in Nature in 1998, Canfield argued that the Ocean had become partially anoxic and sulfidic during the Proterozoic.[1][2]

Peter Ward studies the effects of ocean hypoxia(anoxic) and sulfidic oceans and climate change. He found warming of the ocean caused by a rise of carbon dioxide levels to about 1000 parts per million as a trigger for mass extinction.[3]

The term Strangelove ocean is a model name coined by a study published in 1985, which found a decrease in the δ13C values of planktic skeletons following the Cretaceous–Paleogene extinction event, causing a homogenous ocean in decades or centuries, visible in the boundary sediment layer as a manifestation of the elimination in the surface-to-bottom carbon isotope gradient in ocean waters, the halt of ocean primary production. During a time when carbon fractionation by a photosynthesis-respiration mechanism became ineffective.[4] It was later shown that the burial rate of terrestrial organic carbon (biological pump) was likely unaffected.[5]

Definition

Euxinic Ocean conditions, a term describing restricted hydrologic circulation, leading to stagnant or anaerobic conditions, are the likely factor leading to sulfidic Oceans.[1] Euxinic describes anoxic conditions in the presence of H
2S hydrogen sulfide.[6]

See also

Further reading

Ward, Peter D. "Impact from the Deep". Scientific American 2006 (October): 64–71. 

External links

"Video: Peter Ward Our Future In a World Without Ice Caps" 2013 (April). 

References

  1. 1 2 Canfield, D.E. (1998). [Abstract PDF "A new model for Proterozoic ocean chemistry"] Check |url= value (help) (PDF). Nature 396: 450–453. doi:10.1038/24839.
  2. ↑ Buick, R. (2007). "Did the Proterozoic 'Canfield Ocean'cause a laughing gas greenhouse?". Geobiology 5.2: 97–100. doi:10.1111/j.1472-4669.2007.00110.x.
  3. ↑ Raymond B. Huey, Peter D. Ward (2005). "Hypoxia, Global Warming, and Terrestrial Late Permian Extinctions". Science (AAAS) 308 (5720): 398–401. doi:10.1126/science.1108019.
  4. ↑ K. J. Hsü and J. A. McKenzie (1985). "A "Strangelove" ocean in the earliest Tertiary, in The Carbon Cycle and Atmospheric CO2: Natural Variations Archean to Present". Geophysical Monograph Series (American Geophysical Union) 32: 487–492. doi:10.1029/GM032p0487. Retrieved 2013-09-16.
  5. ↑ LR Kump (1991). "Interpreting carbon-isotope excursions: Strangelove oceans". Geology (Department of Earth System Science Center) 19: 299–302. doi:10.1130/0091-7613(1991)019<0299:ICIESO>2.3.CO;2.
  6. ↑ Timothy W. Lyons, Ariel D. Anbar, Silke Severmann, Clint Scott, and Benjamin C. Gill (January 19, 2009). "Tracking Euxinia in the Ancient Ocean: A Multiproxy Perspective and Proterozoic Case Study". Annual Review of Earth and Planetary Sciences 37: 507–53. doi:10.1146/annurev.earth.36.031207.124233. Retrieved April 11, 2014.


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