Deep radiostratigraphy of the East Antarctic plateau: connecting the Dome C and Vostok ice core sites

• Published in: Journal of Glaciology
• Main Authors: Cavitte, Marie, Blankenship, Donald, Young, Duncan, Schroeder, Dustin, Parrenin, Frédéric, Lemeur, Emmanuel, Macgregor, Joseph, Siegert, Martin
• Other Authors: Institute for Geophysics, University of Texas at Dallas Richardson (UT Dallas), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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 Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-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 Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Imperial College London
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: radio-echo sounding; airborne electromagnetic soundings; ice chronology/dating; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Antarctic; East Antarctic Ice Sheet; Byrd; Totten Glacier; Antarc*; Antarctica; ice core; Ice Sheet; Journal of Glaciology
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01387958; https://hal-insu.archives-ouvertes.fr/insu-01387958/document; https://hal-insu.archives-ouvertes.fr/insu-01387958/file/JOURNAL%20OF%20GLACIOLOGY%20-%20Deep%20radiostratigraphy%20of%20the%20East%20Antarctic%20plateau%20connecting%20the%20Dome%20C%20and%20Vostok%20ice%20core%20sites.pdf; https://doi.org/10.1017/jog.2016.11

International audience Several airborne radar-sounding surveys are used to trace internal reflections around the European Project for Ice Coring in Antarctica Dome C and Vostok ice core sites. Thirteen reflections, spanning the last two glacial cycles, are traced within 200 km of Dome C, a promising region for million-year-old ice, using the University of Texas Institute for Geophysics High-Capacity Radar Sounder. This provides a dated stratigraphy to 2318 m depth at Dome C. Reflection age uncertainties are calculated from the radar range precision and signal-to-noise ratio of the internal reflections. The radar stratigraphy matches well with the Multichannel Coherent Radar Depth Sounder (MCoRDS) radar stratigraphy obtained independently. We show that radar sounding enables the extension of ice core ages through the ice sheet with an additional radar-related age uncertainty of ∼1/3–1/2 that of the ice cores. Reflections are extended along the Byrd-Totten Glacier divide, using University of Texas/Technical University of Denmark and MCoRDS surveys. However, core-to-core connection is impeded by pervasive aeolian terranes, and Lake Vostok's influence on reflection geometry. Poor radar connection of the two ice cores is attributed to these effects and suboptimal survey design in affected areas. We demonstrate that, while ice sheet internal radar reflections are generally isochronal and can be mapped over large distances, careful survey planning is necessary to extend ice core chronologies to distant regions of the East Antarctic ice sheet.