Consulta: creatorFacets:"Debret, Maxime"
Registros recuperados: 6
Data/hora: 13/06/2024 05:28:46

Lake Bourget regional erosion patterns reconstruction reveals Holocene NW European Alps soil evolution and paleohydrology
Provedor de dados: 5
Autores: Arnaud, Fabien; Revillon, Sidonie; Debret, Maxime; Revel, Marie; Chapron, Emmanuel; Jacob, Jeremy; Giguet-covex, Charline; Poulenard, Jerome; Magny, Michel.
Two well-dated ca Holocene-long sedimentary sequences from deepest parts of Lake Bourget provide new insights onto the evolution of erosion patterns at a regional scale in NW European Alps. The combination of high resolution geochemistry - XRF core scanning, calibrated by 150 punctual measurements - and isotope geochemistry (epsilon Nd) of the terrigenous fraction permitted the reconstruction not only of the intensity, but also the type (physical erosion vs. chemical weathering) and the location (Prealpine massifs vs. High Crystalline massifs) of dominant erosion processes. Those data point the persistency of weak erosion fluxes from 9600 to 5500 cal. BP due both to a dry climate and the growing sheltering effect of soils that rapidly progressed between...
Tipo: Text
Palavras-chave: Holocene; Alps; Erosion; Soil dynamics; Paleohydrology.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00106/21723/20064.pdf

High-resolution prediction of organic matter concentration with hyperspectral imaging on a sediment core
Provedor de dados: 5
Autores: Jacq, Kévin; Perrette, Yves; Fanget, Bernard; Sabatier, Pierre; Coquin, Didier; Martinez-lamas, Ruth; Debret, Maxime; Arnaud, Fabien.
In the case of environmental samples, the use of a chemometrics-based prediction model is highly challenging because of the difficulty in experimentally creating a well-ranged reference sample set. In this study, we present a methodology using short wave infrared hyperspectral imaging to create a partial least squares regression model on a cored sediment sample. It was applied to a sediment core of the well-known Lake Bourget (Western Alps, France) to develop and validate a model for downcore high resolution LOI550 measurements used as a proxy of the organic matter. In lake and marine sediment, the organic matter content is widely used, for example, to reconstruct carbon flux variations through time. Organic matter analysis through routine analysis methods...
Tipo: Text
Palavras-chave: Hyperspectral imaging; Chemometrics; Near-infrared spectroscopy; High resolution analysis; Organic matter.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00478/59018/61636.pdf

High-resolution sea surface reconstructions off Cape Hatteras over the last 10 ka
Provedor de dados: 5
Autores: Cleroux, Caroline; Debret, Maxime; Cortijo, Elsa; Duplessy, Jean-claude; Dewilde, Fabien; Reijmer, John; Massei, Nicolas.
This study presents high-resolution foraminiferal-based sea surface temperature, sea surface salinity and upper water column stratification reconstructions off Cape Hatteras, a region sensitive to atmospheric and thermohaline circulation changes associated with the Gulf Stream. We focus on the last 10,000 years (10 ka) to study the surface hydrology changes under our current climate conditions and discuss the centennial to millennial time scale variability. We observed opposite evolutions between the conditions off Cape Hatteras and those south of Iceland, known today for the North Atlantic Oscillation pattern. We interpret the temperature and salinity changes in both regions as co-variation of activities of the subtropical and subpolar gyres. Around 8.3...
Tipo: Text
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00266/37681/36613.pdf

North-south palaeohydrological contrasts in the central Mediterranean during the Holocene: tentative synthesis and working hypotheses
Provedor de dados: 5
Autores: Magny, Michel; Combourieu Nebout, Nathalie; De Beaulieu, Jacques-louis; Bout-roumazeilles, Viviane; Colombaroli, D.; Desprat, Stephanie; Francke, A.; Joannin, Sebastien; Ortu, Elena; Peyron, Odile; Revel, Marie; Sadori, Laura; Siani, Giuseppe; Sicre, Marie-alexandrine; Samartin, S.; Simonneau, A.; Tinner, Willy; Vanniere, Boris; Wagner, B.; Zanchetta, Giovanni; Anselmetti, Flavio S.; Brugiapaglia, E.; Chapron, Emmanuel; Debret, Maxime; Desmet, Marc; Didier, Jean; Essallami, Latifa; Galop, D.; Gilli, A.; Haas, J.n.; Kallel, Nejib; Millet, L.; Stock, Andy; Turon, Jean-louis; Wirth, S.
On the basis of a multi-proxy approach and a strategy combining lacustrine and marine records along a north-south transect, data collected in the central Mediterranean within the framework of a collaborative project have led to reconstruction of high-resolution and well-dated palaeohydrological records and to assessment of their spatial and temporal coherency. Contrasting patterns of palaeohydrological changes have been evidenced in the central Mediterranean: south (north) of around 40 degrees N of latitude, the middle part of the Holocene was characterised by lake-level maxima (minima), during an interval dated to ca. 10 300-4500 cal BP to the south and 9000-4500 cal BP to the north. Available data suggest that these contrasting palaeohydrological...
Tipo: Text
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00264/37570/36902.pdf

Linking Danube River Activity to Alpine Ice-Sheet Fluctuations during the Last Glacial (ca. 33-17 ka BP): insights into the continental signature of Heinrich Stadials
Provedor de dados: 5
Autores: Martinez-lamas, Ruth; Toucanne, Samuel; Debret, Maxime; Riboulot, Vincent; Deloffre, Julien; Boissier, Audrey; Cheron, Sandrine; Pitel, Mathilde; Bayon, Germain; Giosan, Liviu; Soulet, Guillaume.
Offshore archives retrieved from marine/lacustrine environments receiving sediment from large river systems are valuable Quaternary continental records. In the present study, we reconstruct the Danube River activity at the end of the last glacial period based on sedimentological, mineralogical and geochemical analyses performed on long-piston cores from the north-west Black Sea margin. Our data suggest that the Danube River produced hyperpycnal floods throughout the ca. 33-17 ka period. Four main periods of enhanced Danube flood frequency, each of 1.5-3 kyr duration, are recorded at ca. 32.5 30.5 ka (equivalent to the first part of Heinrich Stadial HS 3), at ca. 29-27.5 ka (equivalent to Greenland Stadial 4), at ca. 25.3-23.8 ka (equivalent to HS 2) and at...
Tipo: Text
Palavras-chave: Danube river; Floods; Hyperpycnites; Alpine ice sheet; Heinrich stadials; Seasonality; Black sea.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00613/72556/71612.pdf

Flux estimation, temporal trends and source determination of trace metal contamination in a major tributary of the Seine estuary, France
Provedor de dados: 5
Autores: Gardes, Thomas; Debret, Maxime; Copard, Yoann; Coynel, Alexandra; Deloffre, Julien; Fournier, Matthieu; Revillon, Sidonie; Nizou, Jean; Develle, Anne-lise; Sabatier, Pierre; Marcotte, Stéphane; Patault, Edouard; Faivre, Quentin; Portet-koltalo, Florence.
Anthropogenic impacts on rivers have increased significantly over the past ~150 years, particularly at the beginning of the industrial revolution. Among other signs, this impact is manifested through the addition of trace metals and metalloid elements to rivers. The Eure River watershed in France covers an area of 6017 km2 and is a major tributary of the Seine estuary. It is not exempt from anthropogenic pressures and has been exposed to significant metal discharges over the last 80 years. The average concentrations of metals (i.e., Cr, Co, Ni, Cu, Zn, Ag, Cd, Sb, and Pb), in suspended particulate matter currently transported by the river are high compared to the local geochemical background. Moreover, the lack of correlation between concentration...
Tipo: Text
Palavras-chave: Anthropogenic impacts; Trace metals and metalloids; Eure River watershed; Temporal trends; Particulate metal flux; Pb isotopes.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00618/73046/72159.pdf