ice and sediment records; automated microscopy and image analysis; lacustrine sediments; heavy metal pollution; microbial activity; Antibiotic resistant bacteria; Trace elements; Climate changes; Switzerland
Thevenon Florian, Regier Nicole, Benagli Cinzia, Tonolla Mauro, Adatte Thierry, Wildi Walter, Poté John (2012), Characterization of fecal indicator bacteria in sediments cores from the largest freshwater lake of Western Europe (Lake Geneva, Switzerland)., in Ecotoxicology and environmental safety
, 78, 50-6.
Thevenon F, Adatte T, Wildi W, Pote J (2012), Antibiotic resistant bacteria/genes dissemination in lacustrine sediments highly increased following cultural eutrophication of Lake Geneva (Switzerland), in CHEMOSPHERE
, 86(5), 468-476.
Thevenon F, Graham ND, Chiaradia M, Arpagaus P, Wildi W, Pote J (2011), Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries, in SCIENCE OF THE TOTAL ENVIRONMENT
, 412, 239-247.
Thevenon F, Guedron S, Chiaradia M, Loizeau JL, Pote J (2011), (Pre-) historic changes in natural and anthropogenic heavy metals deposition inferred from two contrasting Swiss Alpine lakes, in QUATERNARY SCIENCE REVIEWS
, 30(1-2), 224-233.
Thevenon Florian (2011), Ancient versus modern mineral dust transported to high-altitude alpine glaciers evidences saharan sources and atmospheric circulation changes, in Atmos. Chem. Phys. Discuss.
, 11, 859-884.
Thevenon F, Williamson D, Bard E, Anselmetti FS, Beaufort L, Cachier H (2010), Combining charcoal and elemental black carbon analysis in sedimentary archives: Implications for past fire regimes, the pyrogenic carbon cycle, and the human-climate interactions, in GLOBAL AND PLANETARY CHANGE
, 72(4), 381-389.
Thevenon F, Anselmetti FS, Bernasconi SM, Schwikowski M (2009), Mineral dust and elemental black carbon records from an Alpine ice core (Colle Gnifetti glacier) over the last millennium, in JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
, 114, 1-11.
Florian Thevenon, Massimo Chiaradia, Thierry Adatte, Christoph Hueglin, John Poté, Characterization ofModern and FossilMineral Dust Transported to High Altitude in theWestern Alps: Saharan Sources and Transport Patterns, in Advances in Meteorology
Florian Thevenon, Thierry Adatte, Jorge E Spangenberg, Flavio S Anselmetti, Elemental (C/N ratios) and isotopic (δ15Norg, δ13Corg) compositions of sedimentary organic matter from a high-altitude mountain lake (Meidsee, 2661 m a.s.l., Switzerland): Implications for Lateglacial, in The Holocene
Thevenon F, Graham ND, Herbez A, Wildi W, Pote J, Spatio-temporal distribution of organic and inorganic pollutants from Lake Geneva (Switzerland) reveals strong interacting effects of sewage treatment plant and eutrophication on microbial abundance, in CHEMOSPHERE
, 84(5), 609-617.
Although many progresses have been made during the last decade for reconstructing the European climate, there is no clear agreement among the existing reconstructions for the pre-instrumental period and this lack of knowledge hinders reliable climatic predictions (IPCC 2007). The original scientific approach in the frame of this project will address the issues of 1) The calibration of the data measured from different climatic archives (sediment and ice cores), 2) The cross-fertilization of new environmental markers providing precise tools for dating those archives, and 3) The physical and chemical characterization of the airborne minerals that were transported to Europe, in regards to past atmospheric circulation changes and anthropogenic human disturbances.This research project aims to analyze an Alpine ice core (Glacier Colle Gnifetti) and two lacustrine sediment cores (Lake Lucerne and Lake Schwaerze) with the same analytical methods. The reconstruction of the natural (aeolian dust) and anthropogenic (fossil fuel combustion) mineral aerosols emissions will provide valuable data for reconstructing the atmospheric (climatic) changes that occurred in Central Europe over the last two millennia on seasonal to decadal time scale. In fact, the transport of mineral aerosols toward the Alps is primarily influenced by the southwesterly dust laden winds from the Sahara, i.e., by the large-scale atmospheric circulation through the North Atlantic Oscillation (NAO)-like variability. The characterization of the airborne minerals entrapped in European climatic archives therefore offers a unique possibility for 1) reconstructing past atmospheric circulation changes, but also for 2) understanding the recent increase in the continental dust flux recorded at high altitude in the Alps, and the possible relationships with the unusual positive phases of NAO observed during the last decades; and for 3) estimating the proportion of the fossil fuel combustion material in the total mineral aerosol emissions supplied to the atmosphere.In order to identify the origin of the mineral dust, sophisticated mineral analyses will be performed using the state-of-the-art material available at the Section of Earth Sciences of the University of Geneva: Raman spectroscopy, ICP-MS, X-ray diffraction (XRD), X-ray micro-fluorescence (uXRF), mass spectrometer (Sr and Nd isotopes), electronic microscope, and automated transmitted light microscope. The characterization of the dust horizons in the high-altitude (Glacier Colle Gnifetti, 4450 m asl) ice-core will allow to decipher the same aeolian events in the low (Lake Lucerne, 434 m asl) and middle (Lake Schwaerze, 2780 m asl) altitudes sediment cores, and to further extend the dust record to the last millennia and to the last decades, respectively. The mineral study of Lake Lucerne sediments will be also used for reconstructing the paleohydrological regional changes (periods of drought and overflow of Lake Lucerne) that occurred in Central Switzerland during the Medieval Warm Period, the Little Ice Age, and the Modern Period on decadal resolution; and for identifying some differences in the crystalline phases produced by the successive high temperature combustion of wood, coal and oil during the steamboat navigation. Finally, this study will provide a new automated image analysis technique, calibrated with geochemical and mineral data, for analyzing/characterizing natural and anthropogenic aerosol emissions/sources in the modern environment and in climatic archives.