Year: 2025
Type: article
Abstract: Ice crystal fabrics can exert significant rheological control on ice sheets and ice shelves, potentially softening or hardening anisotropic ice by several orders of magnitude compared to isotropic ice. We introduce an anisotropic extension of the Shallow Shelf Approximation (SSA), allowing for fabric-induced viscous anisotropy to affect the flow of ice shelves in coupled, transient simulations. We show that the viscous anisotropy of synthetic ice shelves can be parameterized using an isotropic flow enhancement factor, suggesting that existing SSA flow models could, with little effort, approximate the effect of fabric on flow. Next, we propose a new way to directly solve for SSA fabric fields using satellite-derived velocities, assuming velocities are approximately steady and that fabric evolution is dominated by lattice rotation with or without discontinuous dynamic recrystallization. We apply our method to the Ross and Pine Island ice shelves, Antarctica, suggesting that these regions might experience significant fabric-induced hardening and softening depending on the relative strength of lattice rotation and recrystallization. Our results emphasize the ice-dynamical relevance of needing to better constrain the strength of fabric processes. This calls for more widespread fabric and temperature measurements from the field, since measurements are currently too sparse for model validation.
Source: Journal of Glaciology
Institutions: University of Copenhagen, Indiana University Bloomington, Indiana University, University of Tasmania, British Antarctic Survey, Australian Centre for Excellence in Antarctic Science, Monash University, Institut polytechnique de Grenoble, Centre National de la Recherche Scientifique, Institut des Géosciences de l'Environnement, Université Grenoble Alpes
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,600
Awards: G143669390, Micro-scale dependent, time- and space-evolving rheologies: the key for generating strain localization in the Earth, G434337789, The Australian Centre for Excellence in Antarctic Science, Securing Antarctica's Environmental Future, From creeping to sliding: controls on Antarctic Ice Sheet flow processes, RIFT-TIP: Rates of Ice Fracture and Timing of Tabular Iceberg Production
OpenAlex ID: W4412414662