Coulombing faulting from the grain scale to the geophysical scale: Lessons from ice

• Published in: Journal of Physics D: Applied Physics
• Main Authors: Weiss, Jérôme, Schulson, E.M
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-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 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), Thayer School of Engineering, Dartmouth College Hanover
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: 92.10.Rw; 91.55.Fg; 91.10.Kg; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; [SDE.MCG]Environmental Sciences/Global Changes; [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; Sea ice
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00421266; https://doi.org/10.1088/0022-3727/42/21/214017

International audience Coulombic faulting, a concept formulated more than two centuries ago, still remains pertinent in describing the brittle compressive failure of various materials, including rocks and ice. Many questions remain, however, about the physical processes underlying this macroscopic phenomenology. This paper reviews the progress made in these directions during the past few years through the study of ice and its mechanical behaviour in both the laboratory and the field. Fault triggering is associated with the formation of specific features called comb-cracks and involves frictional sliding at the micro(grain)-scale. Similar mechanisms are observed at geophysical scales within the sea ice cover. This scale-independent physics is expressed by the same Coulombic phenomenology from laboratory to geophysical scales, with a very similar internal friction coefficient (μ ≈ 0.8). On the other hand, the cohesion strongly decreases with increasing spatial scale, reflecting the role of stress concentrators on fault initiation. Strong similarities also exist between ice and other brittle materials such as rocks and minerals and between faulting of the sea ice cover and Earth's crust, arguing for the ubiquitous nature of the underlying physics.