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
Modelling δ13C in benthic foraminifera: Insights from model sensitivity experiments
Tilman Hesse,Dieter Wolf-Gladrow,Gerrit Lohmann,Jelle Bijma,Andreas Mackensen,Richard E. Zeebe +5 more
TL;DR: This article used a reaction diffusion model to quantify the effects of different physical, chemical, and biological processes on δ13Cforam of an idealised benthic foraminiferal shell.
Book ChapterDOI
Age Screening of Deep-Sea Corals and the Record of Deep North Atlantic Circulation Change at 15.4KA
Jess F. Adkins,Edward A. Boyle +1 more
TL;DR: In this article, a large number of samples were screened for their ages using an Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) technique and 300 samples were sorted into 5,000 year age bins and several dozen of these are useful for coupled precise uranium series and radiocarbon dating.
Journal ArticleDOI
Similar mid-depth Atlantic water mass provenance during the Last Glacial Maximum and Heinrich Stadial 1
Jacob N W Howe,Jacob N W Howe,Kuo-Fang Huang,Kuo-Fang Huang,Delia W Oppo,Cristiano Mazur Chiessi,Stefan Mulitza,Jurek Blusztajn,Alexander M Piotrowski +8 more
TL;DR: The authors found no change in neodymium isotopic composition, and thus water mass proportions, between the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS1), despite large decreases in carbon isotope values at the onset of HS1 in the same cores.
Book ChapterDOI
Tracer-Nutrient Correlations in the Upper Ocean: Observational and Box Model Constraints on the Use of Benthic Foraminiferal δ13C And Cd/Ca As Paleo-Proxies for the Intermediate-Depth Ocean
Rainer Zahn,Robin Keir +1 more
TL;DR: In this article, the authors show that tracer concentrations seem to be decoupled from nutrient concentrations in high latitudes, presumably because of the effects of gas exchange and varying recycling depths for tracers and nutrients.
References
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Journal ArticleDOI
Smoothing and Differentiation of Data by Simplified Least Squares Procedures.
Journal ArticleDOI
The distribution of 13C of ΣCO2 in the world oceans
TL;DR: In this article, the results from 2252 samples from 107 hydrographic stations are presented as north-south vertical (depth) sections with δ13C contoured at intervals of 0.5−0.0075·AOU.
Journal ArticleDOI
North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature
Edward A. Boyle,Lloyd D Keigwin +1 more
TL;DR: In this paper, the authors show that during a surface cooling event 10,000 to 12,000 years ago, higher Cd/Ca and lower 13C/12C ratios are observed in benthic foraminifera shells from rapidly accumulating western North Atlantic sediments.
Journal ArticleDOI
Comparison of Atlantic and Pacific paleochemical records for the last 215,000 years : changes in deep ocean circulation and chemical inventories
Edward A. Boyle,Lloyd D Keigwin +1 more
TL;DR: In this article, detailed Cd/Ca and δ 13 C data have been obtained for benthic foraminifera from western North Atlantic and Equatorial Pacific sediment cores, which indicate that bottom waters overlying the Atlantic site have been nutrient depleted relative to those at the Pacific site over the last 215,000 years.
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North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature
Edward A. Boyle,Lloyd D Keigwin +1 more