Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz
The presence of contourite drifts in the southern Gulf of Cadiz (GoC) along the Moroccan margin raises questions about the (re)circulation of Mediterranean Outflow Water (MOW) in the GoC and the origin of the currents depositing them. Here, we compare two cores representative of Iberian and Moroccan...
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ftcsic:oai:digital.csic.es:10261/277063 2024-02-11T10:06:24+01:00 Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz Martín Lebreiro, Susana Antón López, Laura Ángela Reguera García, M. Isabel Marzocchi, Alice Ministerio de Ciencia e Innovación (España) European Science Foundation Golfo de Cádiz, Mar Mediterráneo 2018 http://hdl.handle.net/10261/277063 https://doi.org/10.1016/j.quascirev.2018.07.036 https://doi.org/10.13039/501100000782 https://doi.org/10.13039/501100004837 en eng Elsevier #PLACEHOLDER_PARENT_METADATA_VALUE# CTM2008-06399-CO4-02/MAR Euromargins project 01-LEC-EMA24F/CYCIT REN2002-11669-E/MAR https://www.sciencedirect.com/science/article/pii/S027737911730999X Quaternary Science Reviews (2018), 197, p.92-111 0277-3791 http://hdl.handle.net/10261/277063 https://doi.org/10.1016/j.quascirev.2018.07.036 http://dx.doi.org/10.13039/501100000782 http://dx.doi.org/10.13039/501100004837 open Quaternary paleoceanography climate modelling North Atlantic foraminifers stable isotopes sortable silt Mediterranean outflow Morocco contourite drift Gulf of Cadiz Golfo de Cádiz artículo 2018 ftcsic https://doi.org/10.1016/j.quascirev.2018.07.03610.13039/50110000078210.13039/501100004837 2024-01-16T11:27:50Z The presence of contourite drifts in the southern Gulf of Cadiz (GoC) along the Moroccan margin raises questions about the (re)circulation of Mediterranean Outflow Water (MOW) in the GoC and the origin of the currents depositing them. Here, we compare two cores representative of Iberian and Moroccan contourite drifts, covering the last 22 kyr. Although the whole sequence is contouritic in character, it reflects the interaction of distinctive silty-contourite facies (high flow velocity periods) imbedded in muddy-contourite facies (low flow velocity periods). Evidence from benthic foraminifera d13C, sortable silt grain-size, oceanographic CTD profiles and numerical simulations, indicate the Mediterranean water mass as the source of the southern contourite deposits. Our data, therefore, suggests an additional branch of upper-MOW veering southwards off the Straits of Gibraltar along the Moroccan margin. During MIS-(Marine Isotope Stage) 2, upper-MOW was a sluggish current while in the Holocene upper-MOW dominated as a fast, semi-steady flow. Throughout the deglaciation, silty contourites associated with higher flow speeds were deposited in the northern and southern GoC during cold events such as Heinrich Stadial 1 (HS1) and the Younger Dryas, forced by global millennial-scale climate variability. Millennial variability also appears to drive the deposition of silty-contourites in the Holocene. We estimated an average duration of 1 ka for the process of depositing a fast contourite unit. The case of silty-contourite I6 (within HS1) allows us to illustrate with extremely high resolution a “rapid” sequential change in circulation, with gradual slow-down of dense Mediterranean water while surface was freshening (HS1), provoking injection of high-salinity intermediate waters (via contour-currents) into the GoC,and hence the North Atlantic. The subsequent brief collapse of dense water formation in the Mediterranean Sea triggered a major increase in sea surface temperatures (10 C/ka) in the GoC, developing into the next ... Article in Journal/Newspaper North Atlantic Digital.CSIC (Spanish National Research Council) Quaternary Science Reviews 197 92 111 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Quaternary paleoceanography climate modelling North Atlantic foraminifers stable isotopes sortable silt Mediterranean outflow Morocco contourite drift Gulf of Cadiz Golfo de Cádiz |
spellingShingle |
Quaternary paleoceanography climate modelling North Atlantic foraminifers stable isotopes sortable silt Mediterranean outflow Morocco contourite drift Gulf of Cadiz Golfo de Cádiz Martín Lebreiro, Susana Antón López, Laura Ángela Reguera García, M. Isabel Marzocchi, Alice Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz |
topic_facet |
Quaternary paleoceanography climate modelling North Atlantic foraminifers stable isotopes sortable silt Mediterranean outflow Morocco contourite drift Gulf of Cadiz Golfo de Cádiz |
description |
The presence of contourite drifts in the southern Gulf of Cadiz (GoC) along the Moroccan margin raises questions about the (re)circulation of Mediterranean Outflow Water (MOW) in the GoC and the origin of the currents depositing them. Here, we compare two cores representative of Iberian and Moroccan contourite drifts, covering the last 22 kyr. Although the whole sequence is contouritic in character, it reflects the interaction of distinctive silty-contourite facies (high flow velocity periods) imbedded in muddy-contourite facies (low flow velocity periods). Evidence from benthic foraminifera d13C, sortable silt grain-size, oceanographic CTD profiles and numerical simulations, indicate the Mediterranean water mass as the source of the southern contourite deposits. Our data, therefore, suggests an additional branch of upper-MOW veering southwards off the Straits of Gibraltar along the Moroccan margin. During MIS-(Marine Isotope Stage) 2, upper-MOW was a sluggish current while in the Holocene upper-MOW dominated as a fast, semi-steady flow. Throughout the deglaciation, silty contourites associated with higher flow speeds were deposited in the northern and southern GoC during cold events such as Heinrich Stadial 1 (HS1) and the Younger Dryas, forced by global millennial-scale climate variability. Millennial variability also appears to drive the deposition of silty-contourites in the Holocene. We estimated an average duration of 1 ka for the process of depositing a fast contourite unit. The case of silty-contourite I6 (within HS1) allows us to illustrate with extremely high resolution a “rapid” sequential change in circulation, with gradual slow-down of dense Mediterranean water while surface was freshening (HS1), provoking injection of high-salinity intermediate waters (via contour-currents) into the GoC,and hence the North Atlantic. The subsequent brief collapse of dense water formation in the Mediterranean Sea triggered a major increase in sea surface temperatures (10 C/ka) in the GoC, developing into the next ... |
author2 |
Ministerio de Ciencia e Innovación (España) European Science Foundation |
format |
Article in Journal/Newspaper |
author |
Martín Lebreiro, Susana Antón López, Laura Ángela Reguera García, M. Isabel Marzocchi, Alice |
author_facet |
Martín Lebreiro, Susana Antón López, Laura Ángela Reguera García, M. Isabel Marzocchi, Alice |
author_sort |
Martín Lebreiro, Susana |
title |
Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz |
title_short |
Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz |
title_full |
Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz |
title_fullStr |
Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz |
title_full_unstemmed |
Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz |
title_sort |
paleoceanographic and climatic implications of a new mediterranean outflow branch in the southern gulf of cadiz |
publisher |
Elsevier |
publishDate |
2018 |
url |
http://hdl.handle.net/10261/277063 https://doi.org/10.1016/j.quascirev.2018.07.036 https://doi.org/10.13039/501100000782 https://doi.org/10.13039/501100004837 |
op_coverage |
Golfo de Cádiz, Mar Mediterráneo |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
#PLACEHOLDER_PARENT_METADATA_VALUE# CTM2008-06399-CO4-02/MAR Euromargins project 01-LEC-EMA24F/CYCIT REN2002-11669-E/MAR https://www.sciencedirect.com/science/article/pii/S027737911730999X Quaternary Science Reviews (2018), 197, p.92-111 0277-3791 http://hdl.handle.net/10261/277063 https://doi.org/10.1016/j.quascirev.2018.07.036 http://dx.doi.org/10.13039/501100000782 http://dx.doi.org/10.13039/501100004837 |
op_rights |
open |
op_doi |
https://doi.org/10.1016/j.quascirev.2018.07.03610.13039/50110000078210.13039/501100004837 |
container_title |
Quaternary Science Reviews |
container_volume |
197 |
container_start_page |
92 |
op_container_end_page |
111 |
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1790604089014353920 |