Data/hora: 02/06/2024 18:11:23

Provedor de dados: | 5
País: | France
Título: | The timing of deglacial circulation changes in the Atlantic
Autores: | Waelbroeck, C.; Skinner, L. C.; Labeyrie, L.; Duplessy, J. -c.; Michel, E.; Vazquez Riveiros, Natalia; Gherardi, J. M.; Dewilde, F.
Data: | 2011-08
Ano: | 2011
Palavras-chave: | Atlantic Ocean; Benthic oxygen isotope; Last deglaciation; Ocean circulation.
Resumo: | Well-dated benthic foraminifer oxygen isotopic records (delta O-18) from different water depths and locations within the Atlantic Ocean exhibit distinct patterns and significant differences in timing over the last deglaciation. This has two implications: on the one hand, it confirms that benthic delta O-18 cannot be used as a global correlation tool with millennial-scale precision, but on the other hand, the combination of benthic isotopic records with independent dating provides a wealth of information on past circulation changes. Comparing new South Atlantic benthic isotopic data with published benthic isotopic records, we show that (1) circulation changes first affected benthic delta O-18 in the 1000-2200 m range, with marked decreases in benthic delta O-18 taking place at similar to 17.5 cal. kyr B.P. (ka) due to the southward propagation of brine waters generated in the Nordic Seas during Heinrich Stadial 1 (HS1) cold period; (2) the arrival of delta O-18-depleted deglacial meltwater took place later at deeper North Atlantic sites; (3) hydrographic changes recorded in North Atlantic cores below 3000 m during HS1 do not correspond to simple alternations between northern-and southern-sourced water but likely reflect instead the incursion of brine-generated deep water of northern as well as southern origin; and (4) South Atlantic waters at similar to 44 degrees S and similar to 3800 m depth remained isolated from better-ventilated northern-sourced water masses until after the resumption of North Atlantic Deep Water (NADW) formation at the onset of the Bolling-Allerod, which led to the propagation of NADW into the South Atlantic.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00214/32517/31003.pdf

DOI:10.1029/2010PA002007

https://archimer.ifremer.fr/doc/00214/32517/

Editor: | Amer Geophysical Union
Formato: | application/pdf
Fonte: | Paleoceanography (0883-8305) (Amer Geophysical Union), 2011-08 , Vol. 26 , N. PA3213 , P. 1-10

Fonte:

Copyright 2011 by the American Geophysical Union.

info:eu-repo/semantics/openAccess

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