Stable isotope ratios of foraminifera from sediment cores off northeastern Brazil

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Autores principales: Arz, Helge Wolfgang, Pätzold, Jürgen, Wefer, Gerold
Formato: Dataset Open Access
Lenguaje:en
Publicado: PANGAEA 1999
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author Arz, Helge Wolfgang
Pätzold, Jürgen
Wefer, Gerold
author_facet Arz, Helge Wolfgang
Pätzold, Jürgen
Wefer, Gerold
collection Datos científicos de ciencias marinas y ambientales
contents The western South Atlantic boundary currents represent a sensitive system within the global thermohaline circulation (THC). We investigated the impact of deglacial THC changes on the western tropical Atlantic studied in six high resolution sediment cores from the upper continental slope of Brazil. The stratigraphy of the cores is mainly based on 14C AMS dating of monospecific foraminiferal samples. Changes in the upper layer tropical ocean during the deglaciation are inferred from stable oxygen isotope measurements on planktic and benthic foraminifera. Variations in the delta18O residuals are assumed to be mainly temperature related. During the Oldest and Younger Dryas cooling periods, two major deglacial THC disturbances are reported from North Atlantic sediment cores. Concomitant to the repeated THC slowdown, we observe an upper layer warming in the tropical ocean. A reduced northward heat export from the tropical areas during these periods (weak North Brazil Current) is additionally reflected by low meridional gradients in the stable oxygen records. This generally agrees with results from coupled ocean atmosphere models.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_711760
institution PANGAEA
language en
publishDate 1999
publisher PANGAEA
record_format pangaea
spellingShingle Stable isotope ratios of foraminifera from sediment cores off northeastern Brazil
Arz, Helge Wolfgang
Pätzold, Jürgen
Wefer, Gerold
GeoB3104-1; GeoB3202-1; GeoB3229-2; Gravity corer (Kiel type); JOPSII-6; JOPSII-8; NE-Brazilian continental margin; off Rio Paraiba do Sul; SFB261; SL; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents; south of Abrolhos Bank; Victor Hensen
The western South Atlantic boundary currents represent a sensitive system within the global thermohaline circulation (THC). We investigated the impact of deglacial THC changes on the western tropical Atlantic studied in six high resolution sediment cores from the upper continental slope of Brazil. The stratigraphy of the cores is mainly based on 14C AMS dating of monospecific foraminiferal samples. Changes in the upper layer tropical ocean during the deglaciation are inferred from stable oxygen isotope measurements on planktic and benthic foraminifera. Variations in the delta18O residuals are assumed to be mainly temperature related. During the Oldest and Younger Dryas cooling periods, two major deglacial THC disturbances are reported from North Atlantic sediment cores. Concomitant to the repeated THC slowdown, we observe an upper layer warming in the tropical ocean. A reduced northward heat export from the tropical areas during these periods (weak North Brazil Current) is additionally reflected by low meridional gradients in the stable oxygen records. This generally agrees with results from coupled ocean atmosphere models.
title Stable isotope ratios of foraminifera from sediment cores off northeastern Brazil
topic GeoB3104-1; GeoB3202-1; GeoB3229-2; Gravity corer (Kiel type); JOPSII-6; JOPSII-8; NE-Brazilian continental margin; off Rio Paraiba do Sul; SFB261; SL; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents; south of Abrolhos Bank; Victor Hensen
url https://doi.org/10.1594/PANGAEA.711760