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
Tipping Pointedly Colder
TL;DR: Data from multiple ocean basins elucidate an ancient climate transition from greenhouse to icehouse and suggest a new strategy for addressing climate change in the Anthropocene.
Dissertation
Impacts of Revised Geologic Forcing Factors on the Phanerozoic Carbon Cycle
TL;DR: In this article, the main geologic forcings; tectonic uplift, degassing, and basaltic area, of the COPSE biogeochemical model are revised following recent updates to the geologic record.
Journal ArticleDOI
A sedimentação em uma abordagem sistêmica
TL;DR: A sedimentacao pode ser vista como um sistema na superficie da Terra as mentioned in this paper, which possui entrada e saida de massa e energia e transferencia interna of massa.
Estimating Three‐Dimensional Carbon‐To‐Phosphorus Stoichiometry of Exported Marine Organic Matter
TL;DR: In this article , a global steady-state inverse ocean biogeochemistry model and annual mean observed tracers were used to estimate optimal parameters for both linear and power law representations of rC:P in suspended particulate organic matter (POM).
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
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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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