Journal ArticleDOI
Deepwater source variations during the last climatic cycle and their impact on the global deepwater circulation
J.-C. Duplessy,N.J. Shackleton,Richard G. Fairbanks,Laurent Labeyrie,Delia W Oppo,Nejib Kallel +5 more
TLDR
In this paper, a detailed reconstruction of the geographic distribution of ∂13C in benthic foraminifera in the Atlantic Ocean during the last glacial maximum was presented.Abstract:
The degree of similarity of the ∂13C records of the planktonic foraminiferal species N. pachyderma and of the benthic foraminiferal genus Cibicides in the high-latitude basins of the world ocean is used as an indicator of the presence of deepwater sources during the last climatic cycle. Whereas continuous formation of deep water is recognized in the southern ocean, the Norwegian Sea stopped acting as a sink for surface water during isotope stage 4 and the remainder of the last glaciation. However, deep water formed in the north Atlantic south of the Norwegian Sea during the last climatic cycle as early as isotope substage 5d, and this area was also the only active northern source during stages 4–2. A detailed reconstruction of the geographic distribution of ∂13C in benthic foraminifera in the Atlantic Ocean during the last glacial maximum shows that the most important deepwater mass originated from the southern ocean, whereas the Glacial North Atlantic Deep Water cannot be traced south of 40°N. At shallower depth an oxygenated 13C rich Intermediate Water mass extended from 45°N to 15°S. In the Pacific Ocean a ventilation higher than the modern one was also found in open ocean in the depth range 700–2600 m and is best explained by stronger formation of Intermediate Water in high northern latitudes.read more
Citations
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Journal ArticleDOI
Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records
Claire Waelbroeck,Laurent Labeyrie,Laurent Labeyrie,Elisabeth Michel,Jean-Claude Duplessy,Jerry F. McManus,Kurt Lambeck,Estelle Balbon,Monique Labracherie +8 more
TL;DR: In this paper, robust regressions were established between relative sea-level (RSL) data and benthic foraminifera oxygen isotopic ratios from the North Atlantic and Equatorial Pacific Ocean over the last climatic cycle.
Journal ArticleDOI
Glacial/interglacial variations in atmospheric carbon dioxide
Daniel M. Sigman,Edward A. Boyle +1 more
TL;DR: A version of the hypothesis that the whole-ocean reservoir of algal nutrients was larger during glacial times, strengthening the biological pump at low latitudes, where these nutrients are currently limiting is presented.
Journal ArticleDOI
Abrupt climate change
Richard B. Alley,Jochem Marotzke,William D. Nordhaus,Jonathan T. Overpeck,Dorothy M. Peteet,Roger A. Pielke,Raymond T. Pierrehumbert,Peter B. Rhines,Thomas F. Stocker,Lynne D. Talley,John M. Wallace +10 more
TL;DR: Policy-makers should consider expanding research into abrupt climate change, improving monitoring systems, and taking actions designed to enhance the adaptability and resilience of ecosystems and economies.
Journal ArticleDOI
On the Structure and Origin of Major Glaciation Cycles 1. Linear Responses to Milankovitch Forcing
John Imbrie,Edward A. Boyle,Steven C. Clemens,A. Duffy,William R Howard,George Kukla,John E. Kutzbach,Douglas G. Martinson,Andrew McIntyre,Alan C. Mix,B. Molfino,Joseph J. Morley,Larry C. Peterson,Nicklas G Pisias,Warren L. Prell,Maureen E. Raymo,N.J. Shackleton,J. R. Toggweiler +17 more
TL;DR: Starr et al. as mentioned in this paper showed that the 23,000 and 41,000-year cycles of glaciation are continuous, linear responses to orbitally driven changes in the Arctic radiation budget, and used the phase progression in each climatic cycle to identify the main pathways along which the initial, local responses to radiation are propagated by the atmosphere and ocean.
Journal ArticleDOI
The role of ocean-atmosphere reorganizations in glacial cycles
TL;DR: In this paper, a case is made that glacial-to-interglacial transitions involve major reorganizations of the ocean-atmosphere system, and that these reorganizations constitute jumps between stable modes of operation which cause changes in the greenhouse gas content and albedo of the atmosphere.
References
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Journal ArticleDOI
Deep-sea carbonates; Pleistocene dissolution cycles
TL;DR: Foraminiferal evidence has been used for interpretation of calcareous fossil assemblages near and below lysocline in the Pacific Ocean during interglacials as mentioned in this paper.
Journal ArticleDOI
Paleocirculation of the deep north atlantic: 150,000-year record of benthic foraminifera and oxygen-18.
TL;DR: Benthic foraminiferal faunas in a piston core from 3331 meters at 44�N on the Mid-Atlantic Ridge show striking variations in the relative abundance of species, suggesting that North Atlantic deepwater production was much reduced or eliminated at times of Uvigerina peregrina abundance.
Journal ArticleDOI
Geochemical studies of the Weddell sea
TL;DR: In this article, the origin of the Weddell Sea bottom water is discussed in terms of the distributions of a number of geochemical tracers in the major water masses of the sea.
Journal Article
Geochemical studies of the weddell sea
TL;DR: In this article, the origin of the Weddell Sea bottom water is discussed in terms of the distributions of a number of geochemical tracers in the major water masses of the sea.
Journal ArticleDOI
Carbon isotopic changes in benthic foraminifera from the western South Atlantic: Reconstruction of glacial abyssal circulation patterns
William B Curry,G P Lohmann +1 more
TL;DR: Oxygen and carbon-isotopic analyses have been performed on the benthic foraminifer Planulina wuellerstorfi in seven Late Quaternary cores from the Vema Channel-Rio Grande Rise region as discussed by the authors.
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