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Personnes associées (49)
Wolf Hendrik Huwald
Dr. Hendrik Huwald is a scientist at the Laboratory of Cryospheric Sciences (CRYOS) and a lecturer at the Environmental Sciences and Engineering Section (SSIE) of the Swiss Federal Institute of Technology in Lausanne (EPFL). He completed his PhD in 2003 at the Swiss Federal Institute of Technology in Zürich (ETHZ), developing a numerical model for sea ice and studying energy transfer processes in the Arctic. Between 2005 and 2012 he was a post-doctoral fellow and scientist at the Laboratory of Environmental Fluid Mechanics and Hydrology (EFLUM) of EPFL working on Alpine snow-atmosphere interaction, and energy balance-related research mainly in mountain regions. During this time, he designed, led and participated in numerous large field experiments in different environments. In 2013 he joined the newly founded CRYOS laboratory where he conducted research in the domains of snow science, hydrology, boundary layer meteorology and environmental sensing. He has extensive experience with project management both on national and international level.
Johan Alexandre Philippe Gaume
I started my scientific career in 2008 at the Grenoble University in the IRSTEA laboratory where I did my master's thesis on the rheology of dense granular materials using the discrete element method. In the same lab, I followed with a PhD on the numerical modeling of the release depth of extreme avalanches using a combined mechanical-statistical approach and spatial extreme statistics. In 2013 I obtained a postdoc position at the WSL Institute for Snow and Avalanche Research SLF in Davos where I was in charge of developing and applying numerical models to improve the evaluation of avalanche release conditions and thus avalanche forecasting. While my PhD was mostly theoretical and numerical, my postdoc in Davos allowed me to gain a practical expertise by participating in laboratory and field experiments which helped to validate the models I develop. In 2016, I was awarded a SNF grant to work as a research and teaching associate in CRYOS at EPFL on the multiscale modeling of snow and avalanche processes. I developed discrete approaches to model snow micro-structure deformation and failure in order to evaluate constitutive snow models to be used at a larger scale in continuum models. I also developed numerical models for wind-driven snow transport. In 2017, I was a Visiting Scholar at UCLA to work on a Material Point Method (MPM) to simulate both the initiation and propagation of snow avalanches in a unified manner. The UCLA MPM model was initially developed for the Disney movie "Frozen" and has been modified and enriched based on Critical State Soil Mechanics to model the release and flow of slab avalanches. The results of this collaboration have been published in Nature Communications. In 2018, I was awarded the SNF Eccellenza Professorial Fellowship and became professor at EPFL and head of SLAB, the Snow and Avalanche Simulation Laboratory. At SLAB, we study micro-mechanical failure and fracture propagation of porous brittle solids, with applications in snow slab avalanche release. We also simulate avalanche dynamics and flow regime transitions over complex 3D terrain through the development of new models (depth-resolved and depth-averaged) based on MPM.In 2020, I obtained a SPARK grant to develop a new approach to simulate and better understand complex process chains in gravitational mass movements, including permafrost instabilities, rock, snow and ice avalanches and transitions to debris flows.
Philippe Gillet
Philippe GILLET est entré à lEcole normale supérieure de la rue dUlm (Paris) pour y mener des études en sciences de la Terre. En 1983, il obtient un PhD en géophysique à luniversité de Paris VII et rejoint luniversité de Rennes I comme assistant. En 1988, titulaire dun doctorat dEtat, il devient professeur dans cette même université et la quitte en 1992 pour rejoindre Ecole normale supérieure de Lyon.
La formation des chaînes de montagnes, et des Alpes en particuliers, est lobjet de la première partie de sa carrière scientifique. En parallèle, il développe des techniques expérimentales (cellules à enclumes de diamants)qui permettent de simuler en laboratoire les conditions de pression et de température qui règnent au sein des planètes. Lobjectif de ces expériences est de comprendre de quels matériaux sont constituées les profondeurs inatteignables des planètes du système solaire.
En 1997, il commence à travailler sur la matière extraterrestre. Il participe à la description de météorites venant de Mars, de la Lune ou de planètes aujourdhui disparues et explique comment celles-ci ont été expulsées de leur planète dorigine par des chocs titanesques avant darriver sur Terre. Il a aussi participé au programme STARDUST de la NASA et contribué à lidentification de grains de comète ramenés sur Terre après avoir été capturés au voisinage de la comète Wild-II. Ces grains représentent les premiers minéraux de notre système solaire, formés il y a plus de 4,5 milliards dannées. Il a aussi travaillé sur les sujets suivants :
interactions entre bacteries et minéraux;
amorphisation sous pression;
techniques expérimentales: cellule à enclumes de diamant, spectroscopie Raman,diffraction des RX sur source synchrotron, microscopie électronique.
Philippe Gillet a aussi une activité de management de la science et de lenseignement. Il a ainsi dirigé lInstitut National des Sciences de lUnivers du CNRS (France), présidé le synchrotron français SOLEIL, lAgence Nationale de la Recherche française(2007) et lEcole normale supérieure de Lyon. Avant de rejoindre lEPFL il a été le directeur de cabinet du Ministre français de la Recherche et de lEnseignement Supérieur.
Quelques publications :
Ferroir, T., L. Dubrovinsky, A. El Goresy, A. Simionovici, T. Nakamura, and P. Gillet (2010), Carbon polymorphism in shocked meteorites: Evidence for new natural ultrahard phases, Earth and Planetary Science Letters, 290(1-2), 150-154
Barrat J.A., Bohn M., Gillet Ph., Yamaguchi A. (2009) Evidence for K-rich terranes on Vesta from impact spherules. Meteoritics & Planetary Science, 44, 359374.
Brownlee D, Tsou P, Aleon J, et al. (2006) Comet 81P/Wild 2 under a microscope. Science, 314, 1711-1716.
Beck P., Gillet Ph., El Goresy A., and Mostefaoui S. (2005) Timescales of shock processes in chondrites and Martian meteorites. Nature 435, 1071-1074.
Blase X., Gillet Ph., San Miguel A. and Mélinon P. (2004) Exceptional ideal strength of carbon clathrates. Phys. Rev. Lett. 92, 215505-215509.
Gillet Ph. (2002) Application of vibrational spectroscopy to geology. In Handbook of vibrational spectroscopy, Vol. 4 (ed. J. M. Chalmers and P. R. Griffiths), pp. 1-23. John Wiley & Sons.
Gillet Ph., Chen C., Dubrovinsky L., and El Goresy A. (2000) Natural NaAlSi3O8 -hollandite in the shocked Sixiangkou meteorite. Science 287, 1633-1636.