Spectral Emissivity of Phonolite Lava at High Temperature

International audience The rheology and thermodynamical evolution of magma, either in reservoirs, conduits or at the surface, are governed by temperature. To determine the field temperature, remote sensing methods based on measuring the infrared radiance are widely applied, but they are subject to a...

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Bibliographic Details
Published in:IEEE Transactions on Geoscience and Remote Sensing
Main Authors: Li, Hao, Andujar, Joan, Slodczyk, Aneta, De Sousa Meneses, Domingos, Scaillet, Bruno, Echegut, Patrick, Biren, Jonas, Oppenheimer, Clive
Other Authors: Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Magma - UMR7327, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), University of Cambridge UK (CAM), TelluS program of CNRS/INSU with RADIABAR project, ANR-10-LABX-0100,VOLTAIRE,Geofluids and Volatil elements – Earth, Atmosphere, Interfaces – Resources and Environment(2010), ANR-11-EQPX-0036,PLANEX,Planète Expérimentation: simulation et analyse in-situ en conditions extrêmes(2011)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2021
Subjects:
Online Access:https://hal-insu.archives-ouvertes.fr/insu-03433900
https://hal-insu.archives-ouvertes.fr/insu-03433900/document
https://hal-insu.archives-ouvertes.fr/insu-03433900/file/FINAL_VERSION-IEEE-2021.pdf
https://doi.org/10.1109/TGRS.2021.3104657
Description
Summary:International audience The rheology and thermodynamical evolution of magma, either in reservoirs, conduits or at the surface, are governed by temperature. To determine the field temperature, remote sensing methods based on measuring the infrared radiance are widely applied, but they are subject to assumptions and caveats that can propagate into large uncertainties. This is related to the poor knowledge of one of the most critical parameters, namely the spectral emissivity. In this work we aim at filling this gap through in situ spectral emissivity measurements performed over wide temperature (700-1600 K) and spectral ranges (1.25-25 µm) on two representative phonolitic compositions from Erebus (Antartica) and Teide (Spain) volcanoes. The laboratory spectra allow to determine precisely spectral emissivity in the thermal infrared (TIR), middle infrared (MIR), and shortwave infrared (SWIR) ranges. The results reveal the complexity and contrasted behavior of the radiative properties of the two rocks melts, despite their broadly similar composition. The spectral emissivity varies significantly as a function of temperature, composition, crystallinity, thickness, and thermal history. Altogether, the data reveal that emissivity cannot be considered as a constant value and question previous arguments that active lava always has lower emissivity than frozen lava. Finally, the laboratory-measured values of spectral emissivity were used to refine the temperature of Erebus lava lake gathered from previous remote sensing methods.