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
Coccolithophore export in three deep-sea sites of the Aegean and Ionian Seas (Eastern Mediterranean): Biogeographical patterns and biogenic carbonate fluxes
Elisavet Skampa,Maria Triantaphyllou,Margarita D. Dimiza,Alexandra Gogou,Elisa Malinverno,S. Stavrakakis,Constantine Parinos,Ioannis P. Panagiotopoulos,D Tselenti,O. Archontikis,Karl-Heinz Baumann +10 more
TL;DR: In this article, the authors investigated the spatial, temporal and seasonal variability in coccolithophore fluxes, as well as to estimate the coccoith biogenic carbonate contribution to sedimentation process.
Journal ArticleDOI
Ocean colour opportunities from Meteosat Second and Third Generation geostationary platforms
Ewa Kwiatkowska,Kevin Ruddick,Didier Ramon,Quinten Vanhellemont,Carsten Brockmann,Carole Lebreton,Hans Bonekamp +6 more
TL;DR: In this article, the authors describe the ongoing effort to develop operational ocean colour water turbidity and related products and user services from SEVIRI, which can benefit users requiring improved local-area coverage and frequent diurnal observations.
Journal ArticleDOI
Aragonite dissolution protects calcite at the seafloor
Olivier Sulpis,Priyanka Agrawal,Mariette Wolthers,Guy Munhoven,Matthew C. Walker,Jack J. Middelburg +5 more
TL;DR: The authors investigated the role of aragonite dissolution on the early diagenesis of calcite-rich sediments using a novel 3D, micrometric-scale reactive-transport model combined with 3D X-ray tomography structures of natural aragonites and calcite shells.
Journal ArticleDOI
Short-term dissolution response of pelagic carbonate sediments to the invasion of anthropogenic CO2: A model study
TL;DR: In this article, a model experiment is carried out according to the standard CMIP scenario of atmospheric pCO2 increasing at a rate of 1% per year from 286 to 1144 ppm over a 140 year time period.
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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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
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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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