The thermal properties of hydrothermally altered andesites from La Soufrière de Guadeloupe (Eastern Caribbean)

Autor: Michael J. Heap, David E. Jessop, Fabian B. Wadsworth, Marina Rosas-Carbajal, Jean-Christophe Komorowski, H. Albert Gilg, Nadège Aron, Margaux Buscetti, Laura Gential, Margaux Goupil, Mathilde Masson, Lucie Hervieu, Alexandra R.L. Kushnir, Patrick Baud, Lucille Carbillet, Amy G. Ryan, Roberto Moretti
Přispěvatelé: Ecole et Observatoire des Sciences de la Terre (EOST), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), University of British Columbia (UBC), Heap, M. J., Jessop, D. E., Wadsworth, F. B., Rosas-Carbajal, M., Komorowski, J. -C., Gilg, H. A., Aron, N., Buscetti, M., Gential, L., Goupil, M., Masson, M., Hervieu, L., Kushnir, A. R. L., Baud, P., Carbillet, L., Ryan, A. G., Moretti, R., Institut Terre Environnement Strasbourg (ITES), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Durham University, Engineering Geology, TUM School of Engineering and Design, Technical University of Munich, Department of Earth and Environmental Sciences, University of Minnesota, ANR-21-CE49-0010,MYGALE,Modélisation phYsico-chimique des Gradients de l'ALtération hydrothermale: sentinelle de la dynamique d'instabilité gravitaire des volcans Explosifs(2021)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal of Volcanology and Geothermal Research
Journal of Volcanology and Geothermal Research, Elsevier, 2021, 421, ⟨10.1016/j.jvolgeores.2021.107444⟩
Journal of Volcanology and Geothermal Research, 2022, 421, ⟨10.1016/j.jvolgeores.2021.107444⟩
ISSN: 0377-0273
Popis: International audience; The heat flux of an active volcano provides crucial information on volcanic unrest. The hydrothermal activity often responsible for volcanic unrest can be accompanied by an increase in the extent and intensity of hydrothermal alteration, which could influence the thermal properties of the volcanic edifice. Therefore, an understanding of the influence of alteration on the thermal properties of rocks is required to better interpret volcano heat flux data. We provide laboratory measurements of thermal conductivity, thermal diffusivity, and specific heat capacity for variably altered (intermediate to advanced argillic alteration) andesites from La Soufrière de Guadeloupe (Eastern Caribbean). We complement these data with previously published data for altered basaltic-andesites from Merapi (Indonesia) and new data for altered rhyodacites from Chaos Crags (USA). Our data show that thermal conductivity and thermal diffusivity decrease as a function of increasing porosity, whereas the specific heat capacity does not change systematically. Thermal conductivity decreases as a function of alteration (the percentage of secondary minerals) for the rocks from La Soufrière and Merapi (from ~1.6 to ~0.6 W·m−1·K−1 as alteration increases from ~1.5 to >75 wt%), but increases for the rocks from Chaos Crags (from ~1.1 to ~1.5 W·m−1·K−1 as alteration increases from ~6 to ~15 wt%). Although the thermal diffusivity of the rocks from Chaos Crags increases from ~0.65 to ~0.75–0.95 mm2·s−1 as alteration increases from ~6 to ~15 wt%, the thermal diffusivity of the rocks from La Soufrière and Merapi does not appear to be greatly influenced by alteration. The specific heat capacity is not significantly affected by alteration, although there is a slight trend of increasing specific heat capacity with alteration for the rocks from La Soufrière. We conclude that the decrease in thermal conductivity as a function of alteration in the rocks from La Soufrière and Merapi is the result of the low conductivity of the secondary mineral assemblage, and that a combination of the high thermal conductivity of cristobalite and the reduction in porosity as a result of the void-filling mineral precipitation can explain the increase in thermal conductivity in the rocks from Chaos Crags. Calculations show that an increase in alteration of a dome or edifice can result in decreases and increases in heat flow density, depending on the type of alteration. Therefore, alteration-induced changes in the thermal properties of dome or edifice rocks should be considered when interpreting volcano heat flux data. We conclude that it is important not only to monitor the extent and evolution of alteration at active volcanoes, but also the spatial distribution of alteration type.
Databáze: OpenAIRE
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