Investigating processes of marine ice formation in a floating ice tongue by a high-resolution isotopic study

• Published in: Journal of Geophysical Research
• Main Authors: Souchez, R., Tison, J.-L., Lorrain, R., Fléhoc, C., Stiévenard, M., Jouzel, J., Maggi, V.
• Other Authors: Université libre de Bruxelles (ULB), Laboratoire de Modélisation du Climat et de l'Environnement (LMCE), Università degli Studi di Milano Milano (UNIMI)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1995
• Subjects: [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Ice Shelves
• Online Access: https://hal.archives-ouvertes.fr/hal-03334866; https://hal.archives-ouvertes.fr/hal-03334866/document; https://hal.archives-ouvertes.fr/hal-03334866/file/jgr1995Souchez7019.pdf; https://doi.org/10.1029/95JC00142

International audience A better knowledge of boundary conditions near a grounding line is critical for understanding the behavior of ice shelves and floating glaciers. We show here that significant information can be gained from a high-resolution isotopic and textural study of marine ice accreted at the bottom of a floating glacier near its grounding line. Two different types of marine ice have been found. Type 1 is bubble-and debris-free ice with properties which, we believe, can be explained by intrusion of brackish water in open basal fissures. Closing of the fissures by progression of a freezing front from the sides is precluded, and filling by frazil ice is favored. Type 2 is made of thin, clear ice and debris layers which are thought to have formed when a subglacial water-filled sediment enters into contact with seawater and is subjected to freezing under a doublediffusion process. The paper also stresses that in a •iD-•i•80 diagram the alignment of marine ice samples on a mixing line does not necessarily imply a mixture of continental water and seawater in varying proportions.