Stable isotope record of planktonic foraminifera of the South Atlantic

DOI

The central problem of late Quaternary circulation in the South Atlantic is its role in transfer of heat to the North Atlantic, as this modifies amplitude, and perhaps phase, of glacialinterglacial fluctuations. Here we attempt to define the problem and establish ways to attack it. We identify several crucial elements in the dynamics of heat export: (1) warm-water pile-up (and lack thereof) in the Western equatorial Atlantic, (2) general spin-up (or spin-down) of central gyre, tied to SE trades, (3) opening and closing of Cape Valve (Agulhas retroflection), (4) deepwater E-W asymmetry. Means for reconstruction are biogeography, stable isotopes, and productivity proxies. Main results concern overall glacial-interglacial contrast (less pile-up, more spin-up, Cape Valve closed, less NADW during glacial time), dominance of precessional signal in tropics, phase shifts in precessional response. To generate working hypotheses about the dynamics of surface water circulation in the South Atlantic we employ Croll's paradigm that glacial - interglacial fluctuations are analogous to seasonal fluctuations. Our general picture for the last 300 kyrs is that, as concerns the South Atlantic, intensity of surface water (heat) transport depends on the strength of the SE trades. From various lines of evidence it appears that strenger SE trades appeared during glacials and cold substages during interglacials, analogous to conditions in southern winter (August).

Supplement to: Wefer, Gerold; Berger, Wolfgang H; Bickert, Torsten; Donner, Barbara; Fischer, Gerhard; Kemle-von Mücke, Sylvia; Pätzold, Jürgen; Meinecke, Gerrit; Müller, Peter J; Mulitza, Stefan; Niebler, Hans-Stefan; Schmidt, Heike; Schneider, Ralph R; Segl, Monika (1996): Late Quaternary surface circulation of the South Atlantic: The stable isotope record and implications for heat transport and productivity. In: Wefer, G; Berger, W H; Siedler, G & Webb, D (eds.), The South Atlantic: Present and Past Circulation, Springer, Berlin, Heidelberg, 461-502

Identifier
DOI https://doi.org/10.1594/PANGAEA.738529
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.738529
Provenance
Creator Wefer, Gerold ORCID logo; Berger, Wolfgang H; Bickert, Torsten ORCID logo; Donner, Barbara; Fischer, Gerhard ORCID logo; Kemle-von Mücke, Sylvia; Pätzold, Jürgen ORCID logo; Meinecke, Gerrit (ORCID: 0000-0003-4394-088X); Müller, Peter J; Mulitza, Stefan ORCID logo; Niebler, Hans-Stefan; Schmidt, Heike; Schneider, Ralph R ORCID logo; Segl, Monika
Publisher PANGAEA
Publication Year 1996
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 10 datasets
Discipline Geosciences; Natural Sciences
Spatial Coverage (-41.622W, -24.033S, 9.186E, 3.832N); Walvis Ridge; Walvis Ridge, Southeast Atlantic Ocean; Angola Basin; Equatorial Atlantic; West Angola Basin; Amazon Fan
Temporal Coverage Begin 1988-03-02T00:00:00Z
Temporal Coverage End 1991-05-17T00:00:00Z