Brine micro-droplets and solid inclusions in accreted ice from Lake Vostok (East Antarctica)

• Published in: Geophysical Research Letters
• Main Authors: de Angelis, Martine, Morel-Fourcade, Marie-Christine, Barnola, Jean-Marc, Susini, Jean, Duval, Paul
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Joint program involving Russia, France, USA
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Antarctic; East Antarctica; Glacial Lake; Lake Vostok; Antarc*; Antarctica
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00374142; https://hal-insu.archives-ouvertes.fr/insu-00374142/document; https://hal-insu.archives-ouvertes.fr/insu-00374142/file/2005GL022460.pdf; https://doi.org/10.1029/2005GL022460

International audience Lake Vostok, the largest Antarctic sub-glacial lake (14,000 km2), lies beneath nearly 4 km of ice. Sub-glacial geophysical observations and studies of ice accreting at the lake-glacier interface are the only means available to obtain information on the environment and dynamics of this huge water body formed several million years ago. Accretion ice has been studied using high-resolution synchrotron X-Ray micro-fluorescence. For the first time, liquid brine micro-droplets (3-10 μm) are observed, coexisting with large irregular sulfur-rich aggregates (10-800 μm) containing gases and a mixture of very fine particles. Most of these objects are sequestered inside large crystals that grew slowly after ice formation. Their structure and composition support the existence of hydrothermal activity at the lake bottom and the occurrence of haline water pulses carrying fine solid debris and eventually biota from a deeper evaporitic reservoir into the lake.