Data/hora: 14/06/2024 08:46:16

Provedor de dados: | 5
País: | France
Título: | South Atlantic intermediate water advances into the North-east Atlantic with reduced Atlantic meridional overturning circulation during the last glacial period
Autores: | Dubois-dauphin, Quentin; Bonneau, Lucile; Colin, Christophe; Montero-serrano, Jean-carlos; Montagna, Paolo; Blamart, Dominique; Hebbeln, Dierk; Van Rooij, David; Pons-branchu, Edwige; Hemsing, Freya; Wefing, Anne-marie; Frank, Norbert.
Data: | 2016-06
Ano: | 2016
Palavras-chave: | Neodymium isotopes; Cold-water corals; Mediterranean outflow water; East Antarctic intermediate water; Mediterranean sea water; Gulf of Cadiz.
Resumo: | The Nd isotopic composition (εNd) of seawater and cold-water coral (CWC) samples from the Gulf of Cádiz and the Alboran Sea, at a depth of 280-827 m were investigated in order to constrain mid-depth water mass dynamics within the Gulf of Cádiz over the past 40 ka. εNd of glacial and Holocene CWC from the Alboran Sea and the northern Gulf of Cádiz reveals relatively constant values (-8.6 to -9.0 and -9.5 to -10.4, respectively). Such values are similar to those of the surrounding present-day mid-depth waters from the Mediterranean Outflow Water (MOW; εNd ∼ -9.4) and Mediterranean Sea Water (MSW; εNd ∼ -9.9). In contrast, glacial εNd values for CWC collected at thermocline depth (550-827 m) in the southern Gulf of Cádiz display a higher average value (-8.9±0.4) compared to the present-day value (-11.7±0.3). This implies a higher relative contribution of water masses of Mediterranean (MSW) or South Atlantic origin (East Antarctic Intermediate Water, EAAIW). Our study has produced the first evidence of significant radiogenic εNd values (∼ -8) at 19, 23-24 and 27 ka, which are coeval with increasing iceberg discharges and a weakening of Atlantic Meridional Overturning Circulation (AMOC). Since MOW εNd values remained stable during the last glacial period, it is suggested that these radiogenic εNd values most likely reflect an enhanced northward propagation of glacial EAAIW into the eastern Atlantic Basin.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00339/45047/44446.pdf

DOI:10.1002/2016GC006281

https://archimer.ifremer.fr/doc/00339/45047/

Editor: | Amer Geophysical Union
Relação: | info:eu-repo/grantAgreement/EC/FP7/228344/EU//EUROFLEETS
Formato: | application/pdf
Fonte: | Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2016-06 , Vol. 17 , N. 6 , P. 2336-2353

Fonte:

2016 American Geophysical Union

info:eu-repo/semantics/openAccess

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