Natural sites around us, to whom we are extremely attached, sometimes through affective ties, also offer numerous scientific questions. What is happening in front of us? What is going to happen after a perturbation? These questions we are asking outselves, but also the persons around us ask, society asks, companies ask, are not trifle questions. While generally these questions are considered applied problems, related for example to economical resources or polluted sites, the underlying problems and the understanding of the processes taking place are fundamental and delicate questions, and, to be able to provide tentative answers, it is necessary to mobilize the latest concepts and the most refined technologies.
The group "Physics of Natural Sites", established in September 2014, and lead since then by Frédéric Perrier is endowed with the mission, in the context of the Institut de Physique du Globe de Paris, of putting into practice in natural sites the techniques of applied geosciences and the tools developed by the fundamental researches of the institute. Thus, this team proposes natural sites as the living supports contributing to the general intellectual scientific creativity of the institute, and as living supports for higher courses combining fundamental and applied skills. Conversely, natural sites provide examples of processes and situations which are real intellectual and technical challenges leading to the development of new knowledge.
Our group relies on intensive experimental practice, both in the laboratory and in the field to nurture modelling tools and a theoretical physical approach adapted, in the case of natural sites, from out of equilibrium thermodynamics. Rather than proposing an independent subject, the team relies on the competence and knowledge of the other teams of the institute working in natural sites, and to create a common working context together with teams from fundamental physics.
The research of the team is organized around a main topic: hydrothermal systems in the context of active tectonics, and five satellite research actions.
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Séminaire de Vladimir Kossobokov le 19 avril 2017: Times of Increased Probabilities for Occurrence of Catastrophic Earthquakes: 25 Years of Hypothesis Testing in Real Time
Earthquake prediction is an uncertain profession. Many methods for earthquake forecast/prediction have been proposed and some of these methods may be reliable. Some of those might be even useful in mitigating seismic risks and reducing losses due to catastrophic earthquakes and associated phenomena. The pattern recognition algorithm M8, designed in 1984 for prediction of great,magnitude 8, earthquakes, was originally conceived for application targeting other magnitude ranges, so that by 1986 it was already tested in retrospective applications aimed at earthquakes, down to magnitude 5. After successful early forecasts of the 1988 Spitak (Armenia) and the 1989 Loma Prieta (California) earthquakes, a rigid test to evaluate the efficiency of the reproducible intermediate-term middle-range earthquake prediction technique has been designed. Since 1991 every 6 months the algorithm M8, along and in combination with its refinement MSc, has been applied in a real-time prediction mode to seismicity of the entire Earth to outline the areas where magnitude 8.0+ and 7.5+ earthquakes are most likely to occur before the next update. Each of the four statistics achieved to date in the Global Test proves with confidence above 99 percent rather high efficiency of the M8 and M8-MSc predictions limited to intermediate-term middle- and narrow-range accuracy. After 50 semiannual updates in the real-time prediction mode, we (1) confirm statistically approved high confidence of the M8–MSc predictions and (2) conclude a possibility of expanding the territory of the Global Test of the algorithms M8 and MSc.
Séminaire général IPGP de Steve Ingebritsen le 20 avril 2017: HYDROTHERMAL MONITORING OF RESTLESS VOLCANOES IN THE US
The United States has ~170 young volcanoes capable of erupting. From 1980-2015, 44 different U.S. volcanoes produced 115 eruptions and 51 episodes of notable volcanic unrest. Earthquake swarms, sequences of sustained seismic activity, represent the most broadly used indicator of volcanic unrest, yet the vast majority of earthquake swarms do not culminate in an eruption. Hydrothermal systems, more difficult to monitor remotely, are also sensitive to underlying unrest and can provide a critical complement to the seismic and geodetic data streams that are the backbone of most volcano-monitoring efforts. A November 2014 earthquake swarm at Lassen, California, which included the largest earthquake in the area in more than 60 years,was accompanied by a rarely observed outburst of hydrothermal fluids. Long-term, multiparametric monitoring at Lassen and other well-instrumented volcanoes enhances interpretation of unrest and can provide a basis for detailed physical modeling.
Recent student research projects:
- Janvier-Février 2017: Marie Bouih L3 Caractérisation des émissions de CO2 métamorphique sur le système hydrothermal de Bahundanda au Népal central (encadrant Frédéric Girault)
- Avril-Septembre 2016: Bastien Joly M1 Caractérisation pédologique et structurale pour l’interprétation de données d’émanométrie : synthèse de données satellitaires et mesures en laboratoire (encadrant Frédéric Girault, stage en partie en entreprise)
- Juin 2016: Roxane Ferry et Maud Watkinson L1 Etude du radon dans les eaux d'un torrent du Mont Lozère (encadrant Frédéric Perrier)
- Juin 2016: Roxane Ferry L1 Préparation et mesures magnétiques dans des échantillons de sols et de plantes du Pech Merle (encadrants Frédéric Girault et Aude Isambert, stage en collaboration avec l'équipe de Paléomagnétisme)
- Janvier-Février 2016: Etienne Marti L3 Magnétisme environnemental: Etude de la grotte ornée de Pech Merle (encadrante Aude Isambert, stage en collaboration avec l'équipe de Paléomagnétisme)
- Janvier-Février 2015: Marina Bernard L3 Etude du radon dans diverses eaux de la région parisienne (encadrant Frédéric Perrier)
Recent publications :
- Girault, F., F. Perrier, M. Moreira, B. Zanda, P. Rochette, Y. Teitler, Effective radium-226 concentration in meteorites, Geochimica Cosmochimica Acta, 208, 198-219, 2017.
- Girault, F., B. Koirala, M. Bhattarai, F. Perrier, Radon and carbon dioxide around remote Himalayan thermal springs, In Gillmore, G.K., Perrier, F.E., Crockett, R.G.M. (eds) Radon, Health and Natural Hazards. Geological Society, London, Special Publications, 451, SPA451.6, 2016.
- Girault, F., F. Perrier, T. Przylibski, Radon-222 and radium-226 occurrence in water: A review, In Gillmore, G.K., Perrier, F.E., Crockett, R.G.M. (eds) Radon, Health and Natural Hazards. Geological Society, London, Special Publications, 451, SPA451.3, 2016.
- Perrier, F., F. Girault, H. Bouquerel, Effective radium-226 concentration in rocks, soils, plants, and bones, In Gillmore, G.K., Perrier, F.E., Crockett, R.G.M. (eds) Radon, Health and Natural Hazards. Geological Society, London, Special Publications, 451, SPA451.8, 2016.
- Le Mouël, J.-L., V. Kossobokov, F. Perrier, P. Morat, Intermittent heat instabilities in an air plume, Non-Linear Processes in Geophysics, 23, 319-330, 2016.
- Girault, F., F. Perrier, C. Poitou, A. Isambert, H. Théveniaut, V. Laperche, B. Clozel-Leloup, F. Douay, Effective radium concentration in topsoils contaminated by lead and zinc smelters, Science of the Total Environment, 566-567, 865-876, 2016.
- Perrier, F., F. Girault, H. Bouquerel, L. Bollinger, Effective radium concentration in agricultural versus forest topsoils, Journal of Environmental Radioactivity, 160, 123-134, 2016.
- Perrier, F., J. Aupiais, F. Girault, T. Przylibski, H. Bouquerel, Optimized measurement of radium-226 concentration in liquid samples with radon-222 emanation, Journal of Environmental Radioactivity, 157, 52-59, 2016.
- Sapkota, S.N., L. Bollinger, F. Perrier, Fatality rates of the Mw~8.2, 1934, Bihar-Nepal earthquake and comparison with the April 2015 Gorkha earthquake, Earth, Planets Space, 68, 40, 2016.
- Perrier, F., J.-L. Le Mouël, Stationary and transient thermal states of barometric pumping in the access pit of an underground quarry, Science of the Total Environment, 550, 1044-1056, 2016.
- Girault, F., L. Bollinger, M. Bhattarai, B.P. Koirala, C. France-Lanord, S. Rajaure, J. Gaillardet, M. Fort, S.N. Sapkota, F. Perrier, Large-scale organization of carbon dioxide discharge in the Nepal Himalayas, Geophysical Research Letters, 41, 6358-6366, 2014.
- Girault, F., F. Perrier, The Syabru-Bensi hydrothermal system in central Nepal: 2. Modeling and significance of the radon signature, J. Geophysical Research, 119, 4056-4089, 2014.
- Girault, F., F. Perrier, R. Crockett, M. Bhattarai, B.P. Koirala, C. France-Lanord, P. Agrinier, M. Ader, F. Fluteau, C. Gréau, M. Moreira, The Syabru-Bensi hydrothermal system in central Nepal: 1. Characterization of carbon dioxide and radon fluxes, J. Geophysical Research, 119, 4017-4055, 2014.
- Costa, A., Y.J. Suzuki, M. Cerminara, B.J. Devenish, T. Esposti Ongaro, M. Herzog, .R. Van Eaton, L.C. Denby, M. Bursik, M. de Michieli Vitturi, S. Engwell, A. Neri, S. Barsotti, A. Folch, G.Macedonio, F. Girault, G. Carazzo, S. Tait, E. Kaminski, L.G. Mastin, M.J.Woodhouse, J.C. Phillips, A.J. Hogg, W. Degruyter, C. Bonadonna, Results of the eruptive column model inter-comparison study, Journal of Volcanology and Geothermal Research, 326, 2-25, 2016.
- Girault, F., G. Carazzo, S. Tait, E. Kaminski, Combined effects of total grain-size distribution and crosswind on the rise of eruptive volcanic columns, Journal of Volcanology and Geothermal Research, 326, 103-113, 2016.
National Seismological Center, Department of Mines and Geology, Kathmandu
Dr. Soma Nath Sapkota, Deputy Director General
The programs and the developement of the team are supervised by a steering committe including recognized French scientists :
- Yves Caristan, Président, former Director at the French Atomic Energy Commission (CEA), founding chief of CEA/DASE
- Christian Fouillac, former Research Director at BRGM
- Jean-Philippe Avouac, Professor, California Institute of Technology
- Marc Chaussidon, Director of IPGP
- Gauthier Hulot, Deputy Director of IPGP in charge of Research