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| Wilhelm, B.; Arnaud, Fabien; Enters, D.; Allignol, F.; Legaz, Aurelie; Magand, Olivier; Revillon, Sidonie; Giguet-covex, C.; Malet, E.. |
| Flood hazard is expected to increase in the context of global warming. However, long time-series of climate and gauge data at high-elevation are too sparse to assess reliably the rate of recurrence of such events in mountain areas. Here paleolimnological techniques were used to assess the evolution of frequency and magnitude of flash flood events in the North-western European Alps since the Little Ice Age (LIA). The aim was to document a possible effect of the post-19(th) century global warming on torrential floods frequency and magnitude. Altogether 56 flood deposits were detected from grain size and geochemical measurements performed on gravity cores taken in the proglacial Lake Blanc (2170 m a.s.l., Belledonne Massif, NW French Alps). The age model... |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00089/20011/17837.pdf |
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| 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 |
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| 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 |
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