Journal ArticleDOI
Production and accumulation of calcium carbonate in the ocean: Budget of a nonsteady state
TLDR
In this article, it was shown that the oceans are not presently in a steady state, suggesting that outputs have been overestimated or inputs underestimated, that one or more other inputs have not been identified, and/or that one of the missing calcium sources might be groundwater, although its presentday input is probably much smaller than that of rivers.Abstract:
Present-day production of CaCO3 in tne world ocean is calculated to be about 5 billion tons (bt) per year, of which about 3 bt accumulate in sediments; the other 40% is dissolved. Nearly half of the carbonate sediment accumulates on reefs, banks, and tropical shelves, and consists largely of metastable aragonite and magnesian calcite. Deep-sea carbonates, predominantly calcitic coccoliths and planktonic foraminifera, have orders of magnitude lower productivity and accumulation rates than shallow-water carbonates, but they cover orders of magnitude larger basin area. Twice as much calcium is removed from the oceans by present-day carbonate accumulation as is estimated to be brought in by rivers and hydrothermal activity (1.6 bt), suggesting that outputs have been overestimated or inputs underestimated, that one or more other inputs have not been identified, and/or that the oceans are not presently in steady state. One “missing” calcium source might be groundwater, although its present-day input is probably much smaller than that of rivers. If, as seems likely, CaCO3 accumulation presently exceeds terrestial and hydrothermal input, this imbalance presumably is offset by decreased accumulation and increased input during lowered sea level: shallow-water accumulation decreases by an order of magnitude with a 100 m drop in sea level, while groundwater influx increases because of heightened piezometric head and the diagenesis of metastable aragonite and magnesian calcite from subaerially exposed shallow-water carbonates.read more
Citations
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Journal ArticleDOI
Understanding the causes and consequences of past marine carbon cycling variability through models
TL;DR: A comprehensive overview of how marine carbon cycling and the biological carbon pump is treated in available paleoclimate models, with the aim of critically evaluating their ability to help interpret past marine carbon cycle and climate dynamics is provided in this article.
Book ChapterDOI
Carbonate fluxes and calcareous nannoplankton
TL;DR: For example, there appears to be a continuous gradation in the level of susceptibility of coccoliths to dissolution, from forms that dissolve in the near-saturated waters of the surface ocean to those that are among the most dissolution-resistant forms of calcite as mentioned in this paper.
Journal ArticleDOI
Transports and budgets of total inorganic carbon in the subpolar and temperate North Atlantic
TL;DR: In this article, the authors examined the contemporary and pre-industrial TIC budgets in the subpolar and temperate North Atlantic based on two different approximations for the budget definitions.
Journal ArticleDOI
Hierarchically structured scleractinian coral biocrystals.
TL;DR: Results of microscopic and diffraction studies are reconciled within a new, minute-scale model of scleractinian biomineral fibers, finding that the lattice parameters and internal strains of the bio-aragonite are larger than in mineral aragonite, and lattice parameter elongations andinternal strains reveal directional anisotropy with respect to crystallographic axes.
Journal ArticleDOI
Calcium carbonate cycling in future oceans and its influence on future climates
TL;DR: In the last few years, evidence has accumulated that calcifying organisms are likely to be affected by ocean acidification, leading most probably to an almost complete cessation of deep-sea calcium carbonate burial for some centuries as discussed by the authors.
References
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Journal ArticleDOI
A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation
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Journal ArticleDOI
The carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years
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Journal ArticleDOI
Vostok ice core provides 160,000-year record of atmospheric CO2
TL;DR: In this article, direct evidence of past atmospheric CO2 changes has been extended to the past 160,000 years from the Vostok ice core, showing an inherent phenomenon of change between glacial and interglacial periods.
Journal ArticleDOI
Biological communities at the Florida escarpment resemble hydrothermal vent taxa.
Charles K. Paull,Barbara Hecker,R.F. Commeau,R. P. Freeman-Lynde,C. Neumann,W.P. Corso,Stjepko Golubic,J.E. Hook,Elisabeth L. Sikes,Joseph R. Curray +9 more
TL;DR: Dense biological communities of large epifaunal taxa similar to those found along ridge crest vents at the East Pacific Rise were discovered in the abyssal Gulf of Mexico.
Journal ArticleDOI
A biogeochemical study of the coccolithophore, Emiliania huxleyi, in the North Atlantic
Patrick M. Holligan,Emilio Fernández,James Aiken,William M. Balch,Philip W. Boyd,Peter H. Burkill,Miles S. Finch,Stephen B. Groom,Gillian Malin,Kerstin Muller,Duncan A. Purdie,Carol V. Robinson,Charles C. Trees,Suzanne M. Turner,Paul van der Wal +14 more
TL;DR: The biogeochemical properties of an extensive bloom (∼250,000 km2) of the coccolithophore, Emiliania huxleyi, in the north east Atlantic Ocean were investigated in June 1991.
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