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
Projected reversal of oceanic stable carbon isotope ratio depth gradient with continued anthropogenic carbon emissions
TL;DR: In this paper , the authors present simulations from an observationally constrained ocean model under various greenhouse gas emissions scenarios, and conclude that the Paleocene-Eocene Thermal Maximum is a geologic analogue of future global carbon cycle perturbations under continued rapid anthropogenic carbon emissions.
Journal ArticleDOI
Phytoplankton Dynamics and Biogeochemistry of the Black Sea
V. A. Silkin,L. A. Pautova,O. I. Podymov,V. K. Chasovnikov,Anna V. Lifanchuk,Alexey V. Fedorov +5 more
TL;DR: In this paper , the authors investigated the seasonal dynamics of phytoplankton and the nutrient concentrations and their ratios in the northeastern Black Sea in 2017-2021 and found that large diatoms dominated in summer with a biomass exceeding 1000 mg m−3 annually, except in 2019.
Journal ArticleDOI
Interannual variability (2000–2013) of mesopelagic and bathypelagic particle fluxes in relation to variable sea ice cover in the eastern Fram Strait
Ian Salter,Eduard Bauerfeind,Kirsten Fahl,Morten Hvitfeldt Iversen,Catherine Lalande,Simon Ramondenc,Wilken-Jon von Appen,Claudia Wekerle,Eva-Maria Nöthig +8 more
TL;DR: In this article , the authors present long-term sediment trap records (2000-2013) from mesopelagic (200 m) and bathypelagic (2,300 m) depths at two locations (HGIV and HGN) in the Fram Strait subjected to variable ice conditions.
DissertationDOI
Chemical Controls on the Dissolution Kinetics of Calcite in Seawater
TL;DR: In this article, it is shown that carbon-13-labeled calcite is dissolved in underaturated seawater, and the dissolution rate is a highly nonlinear function of calcite saturation state, which can be used to constrain mass fluxes due to precipitation and dissolution as a function of saturation state.
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
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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.
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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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