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| Registros recuperados: 13 | |
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| Caley, Thibaut; Extier, Thomas; Collins, James A.; Schefuss, Enno; Dupont, Lydie; Malaize, Bruno; Rossignol, Linda; Souron, Antoine; Mcclymont, Erin L.; Jimenez-espejo, Francisco J.; Garcia-comas, Carmen; Eynaud, Frederique; Martinez, Philippe; Roche, Didier M.; Jorry, Stephan; Charlier, Karine; Wary, Melanie; Gourves, Pierre-yves; Billy, Isabelle; Giraudeau, Jacques. |
| The past two million years of eastern African climate variability is currently poorly constrained, despite interest in understanding its assumed role in early human evolution1,2,3,4. Rare palaeoclimate records from northeastern Africa suggest progressively drier conditions2,5 or a stable hydroclimate6. By contrast, records from Lake Malawi in tropical southeastern Africa reveal a trend of a progressively wetter climate over the past 1.3 million years7,8. The climatic forcings that controlled these past hydrological changes are also a matter of debate. Some studies suggest a dominant local insolation forcing on hydrological changes9,10,11, whereas others infer a potential influence of sea surface temperature changes in the Indian Ocean8,12,13. Here we show... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00449/56059/57581.pdf |
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| Zumaque, J.; Eynaud, Frederique; Zaragosi, S.; Marret, F.; Matsuzaki, K. M.; Kissel, C.; Roche, D. M.; Malaize, B.; Michel, E.; Billy, I.; Richter, T.; Palis, E.. |
| The rapid climatic variability characterising the Marine Isotopic Stage (MIS) 3 (similar to 60-30 cal ka BP) provides key issues to understand the atmosphere-ocean-cryosphere dynamics. Here we investigate the response of sea-surface paleoenvironments to the MIS3 climatic variability through the study of a high resolution oceanic sedimentological archive (core MD99-2281, 60 degrees 21' N; 09 degrees 27' W; 1197m water depth), retrieved during the MD114-IMAGES (International Marine Global Change Study) cruise from the southern part of the Faeroe Bank. This sector was under the proximal influence of European ice sheets (Fennoscandian Ice Sheet to the East, British Irish Ice Sheet to the South) during the last glacial and thus probably responded to the MIS3... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00139/25060/23168.pdf |
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| Mary, Yannick; Eynaud, Frederique; Colin, Christophe; Rossignol, Linda; Brocheray, Sandra; Mojtahid, Meryem; Garcia, Jennifer; Peral, Marion; Howa, Helene; Zaragosi, Sebastien; Cremer, Michel. |
| This paper documents the evolution over the last 10 kyr of one of the key parameters of climate: sea-surface temperatures (SSTs) in the North Atlantic. We focus on the southern Bay of Biscay, a highly sensitive oceanographic area regarding the dynamics of the North Atlantic subpolar and subtropical gyres (SPG and STG respectively). This site furthermore offers unique sedimentary environments characterized by exceptional accumulation rates, enabling the study of Holocene archives at (infra) centennial scales. Our results mainly derive from planktonic foraminiferal association analysis on two cores from the southern Landes Plateau. These associations are used as the basis of modern analogue technique transfer functions to track past hydrographical changes.... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53177/55077.pdf |
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| Lambert, Clement; Penaud, Aurelie; Vidal, Muriel; Klouch, Khadidja; Gregoire, Gwendoline; Ehrhold, Axel; Eynaud, Frederique; Schmidt, Sabine; Ragueneau, Olivier; Siano, Raffaele. |
| For the first time a very high resolution palynological study (mean resolution of 1 to 5 years) was carried out over the last 150 years in a French estuarine environment (Bay of Brest; NW France), allowing direct comparison between the evolution of landscapes, surface water, and human practices on Bay of Brest watersheds, through continental (especially pollen grains) and marine (phytoplanktonic microalgae: cysts of dinoflagellates or dinocysts) microfossils. Thanks to the small size of the watersheds and the close proximity of the depositional environment to the mainland, the Bay of Brest represents an ideal case study for palynological investigations. Palynological data were then compared to published palaeo-genetic analyses conducted on the same core... |
| Tipo: Text |
Palavras-chave: Pollen grains; Dinoflagellate cysts; Estuarine dynamics; River runoff; Climate variability. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00410/52110/52813.pdf |
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| Toucanne, Samuel; Soulet, Guillaume; Freslon, Nicolas; Jacinto, Ricardo Silva; Dennielou, Bernard; Zaragosi, Sebastien; Eynaud, Frederique; Bourillet, Jean-francois; Bayon, Germain. |
| Reconstructing Northern Hemisphere ice-sheet oscillations and meltwater routing to the ocean is important to better understand the mechanisms behind abrupt climate changes. To date, research efforts have mainly focused on the North American (Laurentide) ice-sheets (LIS), leaving the potential role of the European Ice Sheet (EIS), and of the Scandinavian ice-sheet (SIS) in particular, largely unexplored. Using neodymium isotopes in detrital sediments deposited off the Channel River, we provide a continuous and well-dated record for the evolution of the EIS southern margin through the end of the last glacial period and during the deglaciation. Our results reveal that the evolution of EIS margins was accompanied with substantial ice recession (especially of... |
| Tipo: Text |
Palavras-chave: European ice-sheet; Channel River; Meltwater; Deglaciation; Neodymium; Termination. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00272/38346/36675.pdf |
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| Kaboth-bahr, Stefanie; Bahr, Andre; Zeeden, Christian; Toucanne, Samuel; Eynaud, Frederique; Jimenez-espejo, Francisco; Rohl, Ursula; Friedrich, Oliver; Pross, Joerg; Lowemark, Ludvig; Lourens, Lucas J.. |
| The dynamics of Northern Hemisphere ice sheets during Late Quaternary glacials have yet been dominantly examined from a Laurentide Ice Sheet perspective, which helped shaping the idea of moisture-starved glacials and small-scale ice volume variability. However, the waxing and waning of the European Ice Sheet (EIS) casts doubt on this perception. Understanding EIS dynamics under glacial boundary conditions is crucial because its meltwater pulses influence global climate by weakening deepwater formation in the North Atlantic Ocean. Here we show that the advection of subtropical water toward the continental margin of western Europe lead to enhanced moisture availability on the continent and fueled the growth of EIS lobes during glacials. This warm-water... |
| Tipo: Text |
Palavras-chave: Mediterranean Outflow variability; European Ice Sheet dynamics; Marine‐terrestrial feedback in the Euro‐Mediterranean realm; Glacial climate variability; Low‐latitude forcing of high‐latitude glaciations. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00457/56831/58657.pdf |
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| Eynaud, Frederique; Malaize, Bruno; Zaragosi, Sebastien; De Vernal, Anne; Scourse, James; Pujol, Claude; Cortijo, Elsa; Grousset, Francis E.; Penaud, Aurelie; Toucanne, Samuel; Turon, Jean-louis; Auffret, Gerard. |
| During the late Quaternary, both external and internal forcings have driven major climatic shifts from glacial to interglacial conditions. Nonlinear climatic steps characterized the transitions leading to these extrema, with intermediate excursions particularly well expressed in the dynamics of the Northern Hemisphere cryosphere. Here we document the impact of these dynamics on the north-eastern North Atlantic Ocean, focussing on the 35-10 ka interval. Sea-surface salinities have been reconstructed quantitatively based on two independent methods from core MD95-2002, recovered from the northern Bay of Biscay adjacent to the axis of the Manche paleoriver outlet and thus in connection with proximal European ice sheets and glaciers. Quantitative... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19762/20100.pdf |
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| Dylmer, C. V.; Giraudeau, J.; Eynaud, Frederique; Husum, K.; De Vernal, A.. |
| Three marine sediment cores distributed along the Norwegian (MD95-2011), Barents Sea (JM09-KA11-GC), and Svalbard (HH11-134-BC) continental margins have been investigated in order to reconstruct changes in the poleward flow of Atlantic waters (AW) and in the nature of upper surface water masses within the eastern Nordic Seas over the last 3000 yr. These reconstructions are based on a limited set of coccolith proxies: the abundance ratio between Emiliania huxleyi and Coccolithus pelagicus, an index of Atlantic vs. Polar/Arctic surface water masses; and Gephyrocapsa muellerae, a drifted coccolith species from the temperate North Atlantic, whose abundance changes are related to variations in the strength of the North Atlantic Current. The entire investigated... |
| Tipo: Text |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00181/29239/27636.pdf |
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| Penaud, Aurelie; Eynaud, Frederique; Luise Voelker, Antje Helga; Turon, Jean-louis. |
| New dinoflagellate cyst (dinocyst) analyses were carried out at high resolution in core MD99-2339, retrieved from a contouritic field in the central part of the Gulf of Cadiz, for the Marine Isotope Stage (MIS) 3 interval, allowing for discussion of palaeohydrological changes over the last 50 ky in the subtropical NE Atlantic Ocean. Some index dinocyst taxa, according to their (palaeo) ecological significance, shed light on significant sea-surface changes. Superimposed on the general decreasing pattern of dinocyst export to the seafloor over the last 50 ky, paralleling the general context of decreasing aeolian dust fertilization, a complex variability in dinocyst assemblages was detected at the millennial timescale. Enhanced fluvial discharges occurred... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53220/54807.pdf |
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| Eynaud, Frederique; De Abreu, Lucia; Voelker, Antje; Schoenfeld, Joachim; Salgueiro, Emilia; Turon, Jean-louis; Penaud, Aurelie; Toucanne, Samuel; Naughton, Filipa; Goni, Maria Fernanda Sanchez; Malaize, Bruno; Cacho, Isabel. |
| This paper documents the migration of the Polar Front (PF) over the Iberian margin during some of the cold climatic extremes of the last 45 ka. It is based on a compilation of robust and coherent paleohydrological proxies obtained from eleven cores distributed between 36 and 42 degrees N. Planktonic delta O-18 (Globigerina bulloides), ice-rafted detritus concentrations, and the relative abundance of the polar foraminifera Neogloboquadrina pachyderma sinistral were used to track the PF position. These three data sets, compared from core to core, show a consistent evolution of the sea surface paleohydrology along the Iberian margin over the last 45 ka. We focused on five time slices representative of cold periods under distinct paleoenvironmental forcings:... |
| Tipo: Text |
Palavras-chave: Polar Front; LGM; Heinrich events. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00218/32909/31415.pdf |
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| Wary, Melanie; Eynaud, Frederique; Swingedouw, Didier; Masson-delmotte, Valerie; Matthiessen, Jens; Kissel, Catherine; Zumaque, Jena; Rossignol, Linda; Jouzel, Jean. |
| Dansgaard-Oeschger oscillations constitute one of the most enigmatic features of the last glacial cycle. Their cold atmospheric phases have been commonly associated with cold sea-surface temperatures and expansion of sea ice in the North Atlantic and adjacent seas. Here, based on dinocyst analyses from the 48-30 ka interval of four sediment cores from the northern Northeast Atlantic and southern Norwegian Sea, we provide direct and quantitative evidence of a regional paradoxical seesaw pattern: cold Greenland and North Atlantic phases coincide with warmer sea-surface conditions and shorter seasonal sea-ice cover durations in the Norwegian Sea as compared to warm phases. Combined with additional palaeorecords and multi-model hosing simulations, our results... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53149/55328.pdf |
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| Toucanne, Samuel; Zaragosi, Sebastien; Bourillet, Jean-francois; Marieu, Vincent; Cremer, Michel; Kageyama, Masa; Van Vliet-lanoe, Brigitte; Eynaud, Frederique; Turon, Jean-louis; Gibbard, Philip L.. |
| The Fleuve Manche (English Channel) palaeoriver represents the largest river system that drained the European continent during Pleistocene lowstands, particularly during the Elsterian (Marine Isotope Stage 12) and Saalian Drenthe (MIS 6) glaciations when extensive ice advances into the North Sea area forced the central European rivers to flow southwards to the Bay of Biscay (NE Atlantic). Numerous long piston cores and high-resolution acoustic data from the northern Bay of Biscay have been correlated using a well-constrained chronostratigraphical framework, and for the first time allow the estimation of the discharge of the Fleuve Manche palaeoriver at the end of the last glacial period (i.e. Weichselian). Our results, discussed in the light of... |
| Tipo: Text |
Palavras-chave: Fleuve Manche palaeoriver; English Channel; Sediment and meltwater discharge; European ice sheet; Deglaciation; Termination 1; North Sea area; European drainage network. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11310/7858.pdf |
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| Toucanne, Samuel; Zaragosi, S.; Bourillet, Jean-francois; Cremer, M.; Eynaud, Frederique; Van Vliet-lanoe, B.; Penaud, A.; Fontanier, C.; Turon, J. L.; Cortijo, E.; Gibbard, P. L.. |
| Continuous high-resolution mass accumulation rates (MAR) and X-ray fluorescence (XRF) measurements from marine sediment records in the Bay of Biscay (NE Atlantic) have allowed the determination of the timing and the amplitude of the ‘Fleuve Manche’ (Channel River) discharges during glacial stages MIS 10, MIS 8, MIS 6 and MIS 4–2. These results have yielded detailed insight into the Middle and Late Pleistocene glaciations in Europe and the drainage network of the western and central European rivers over the last 350 kyr. This study provides clear evidence that the ‘Fleuve Manche’ connected the southern North Sea basin with the Bay of Biscay during each glacial period and reveals that ‘Fleuve Manche’ activity during the glaciations MIS 10 and MIS 8 was... |
| Tipo: Text |
Palavras-chave: Northern north sea; Late weichselian glaciation; Western iberian margin; Abrupt climate change; C 14 YR BP; Deep sea; Heinrich events; Norwegian margin; Millennial scale; English channel. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00011/12261/9037.pdf |
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| Registros recuperados: 13 | |
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