Hydrogen emissions from Erebus volcano, Antarctica

• Published in: Bulletin of Volcanology
• Main Authors: Moussallam, Yves, Oppenheimer, Clive, Aiuppa, Alessandro, Giudice, Gaetano, Moussallam, Manuel, Kyle, Philip R.
• Other Authors: Department of Geography Cambridge, UK, University of Cambridge UK (CAM), Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Dipartimento DiSTeM, Università di Palermo, Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom Paris (IMT)-Centre National de la Recherche Scientifique (CNRS), New Mexico Institute of Mining and Technology New Mexico Tech (NMT), ANT-0838817 from the Office of Polar Programs (National Science Foundation), European Project: 202844,EC:FP7:ERC,ERC-2007-StG,DEMONS(2008)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: Volcanic degassing; Lava lake; Magma redox conditions; Hydrogen; Erebus volcano; [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology; [SDE.MCG]Environmental Sciences/Global Changes; Lava Lake; Antarc*; Antarctica
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00782326; https://hal-insu.archives-ouvertes.fr/insu-00782326/document; https://hal-insu.archives-ouvertes.fr/insu-00782326/file/Moussallam-BulVol-2012.pdf; https://doi.org/10.1007/s00445-012-0649-2

International audience The continuous measurement of molecular hydrogen (H2) emissions from passively degassing volcanoes has recently been made possible using a new generation of low-cost electrochemical sensors. We have used such sensors to measure H2, along with SO2, H2O and CO2, in the gas and aerosol plume emitted from the phonolite lava lake at Erebus volcano, Antarctica. The measurements were made at the crater rim between December 2010 and January 2011. Combined with measurements of the long-term SO2 emission rate for Erebus, they indicate a characteristic H2 flux of 0.03 kg s-1 (2.8 Mg day-1). The observed H2 content in the plume is consistent with previous estimates of redox conditions in the lava lake inferred from mineral compositions and the observed CO2/CO ratio in the gas plume (∼0.9 log units below the quartz-fayalite-magnetite buffer). These measurements suggest that H2 does not combust at the surface of the lake, and that H2 is kinetically inert in the gas/aerosol plume, retaining the signature of the high-temperature chemical equilibrium reached in the lava lake. We also observe a cyclical variation in the H2/SO2 ratio with a period of ∼10 min. These cycles correspond to oscillatory patterns of surface motion of the lava lake that have been interpreted as signs of a pulsatory magma supply at the top of the magmatic conduit.