Consulta: creatorFacets:"Mazaud, Alain"
Registros recuperados: 3
Data/hora: 26/07/2024 22:47:15

A 27 kyr terrestrial biomarker record in the southern Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Sicre, Marie-alexandrine; Labeyrie, Laurent; Ezat, Ullah; Mazaud, Alain; Turon, Jean-louis.
Terrestrial inputs were reconstructed using high molecular weight n-alkane concentrations recorded in the sub-Antarctic Indian Ocean core MD94-103 (45 degrees 35'S, 86 degrees 31'E, 3560 m) to examine regional changes in the atmospheric circulation over the last 27 kyr. This record was compared to the dust content of EPICA-Dome C ice and continental data from South Africa ( e. g., pollen sequences and isotope records in speleothems) to get a comprehensive understanding of atmospheric links between low and midlatitudes of the Indian Ocean. Terrestrial n-alkanes indicate higher glacial than Holocene inputs and marked glacial oscillations. Minimum values during the Last Glacial Maximum (LGM) are consistent with colder and drier climate and presumably caused...
Tipo: Text
Palavras-chave: Biomarker; Glacial; Indian Ocean; Marine sediments; Paleoclimate; Terrestrial.
Ano: 2006
URL: https://archimer.ifremer.fr/doc/00234/34547/33355.pdf

Glacial heterogeneity in Southern Ocean carbon storage abated by fast South Indian deglacial carbon release
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Gottschalk, Julia; Michel, Elisabeth; Thöle, Lena M.; Studer, Anja S.; Hasenfratz, Adam P.; Schmid, Nicole; Butzin, Martin; Mazaud, Alain; Martínez-garcía, Alfredo; Szidat, Sönke; Jaccard, Samuel L.
Past changes in ocean 14C disequilibria have been suggested to reflect the Southern Ocean control on global exogenic carbon cycling. Yet, the volumetric extent of the glacial carbon pool and the deglacial mechanisms contributing to release remineralized carbon, particularly from regions with enhanced mixing today, remain insufficiently constrained. Here, we reconstruct the deglacial ventilation history of the South Indian upwelling hotspot near Kerguelen Island, using high-resolution 14C-dating of smaller-than-conventional foraminiferal samples and multi-proxy deep-ocean oxygen estimates. We find marked regional differences in Southern Ocean overturning with distinct South Indian fingerprints on (early de-)glacial atmospheric CO2 change. The dissipation of...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00662/77418/79081.pdf

The influence of high-latitude flux lobes on the Holocene paleomagnetic record of IODP Site U1305 and the northern North Atlantic
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Stoner, Joseph S.; Channell, James E. T.; Mazaud, Alain; Strano, Sarah E.; Xuan, Chuang.
Paleomagnetic analysis and radiocarbon dating of an expanded Holocene deep-sea sediment sequence recovered by Integrated Ocean Drilling Program (IODP) Expedition 303 from Labrador Sea Site U1305 (Lat.: 57 degrees 28.5 N, Long.: 48 degrees 31.8 W, water depth 3459 m) provides insights into mechanisms that drive both paleomagnetic secular variation (PSV) and magnetization acquisition in deep-sea sediments. Seventeen radiocarbon dates on planktonic foraminifera define postglacial (ca. 8 ka) sedimentation rates as ranging from 35 to &gt; 90 cm/kyr. Alternating field (AF) demagnetization of u-channel samples show that these homogeneous sediments preserve a strong, stable, and consistently well-defined component magnetization. Normalized remanence records pass...
Tipo: Text
Palavras-chave: Paleomagnetism; North Atlantic; Paleointensity.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00264/37480/36500.pdf