Helium and Neon in the Accreted Ice of the Subglacial Antarctic Lake Vostok

• Published in: Geophysical Research Letters
• Main Authors: Jean-Baptiste, P., Fourré, E., Petit, J. R., Lipenkov, V., Bulat, S., Chetverikov, Y., Raynaud, D.
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Observatoire des Sciences de l'Univers de Grenoble (Fédération OSUG)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDU]Sciences of the Universe [physics]; Antarctic; Lake Vostok; Antarc*
• Online Access: https://insu.hal.science/insu-03706507; https://insu.hal.science/insu-03706507v1/document; https://insu.hal.science/insu-03706507v1/file/Geophysical%20Research%20Letters%20-%202018%20-%20Jean%25u2010Baptiste%20-%20Helium%20and%20Neon%20in%20the%20Accreted%20Ice%20of%20the%20Subglacial%20Antarctic%20Lake.pdf; https://doi.org/10.1029/2018GL078068

International audience We analyzed helium and neon in 24 samples from between 3,607 and 3,767 m (i.e., down to 2 m above the lake-ice interface) of the accreted ice frozen to the ceiling of Lake Vostok. Within uncertainties, the neon budget of the lake is balanced, the neon supplied to the lake by the melting of glacier ice being compensated by the neon exported by lake ice. The helium concentration in the lake is about 12 times more than in the glacier ice, with a measured 3 He/ 4 He ratio of 0.12 ± 0.01 R a . This shows that Lake Vostok's waters are enriched by a terrigenic helium source. The 3 He/ 4 He isotope ratio of this helium source was determined. Its radiogenic value (0.057 × R a ) is typical of an old continental province, ruling out any magmatic activity associated with the tectonic structure of the lake. It corresponds to a low geothermal heat flow estimated at 51 mW/m 2 .