A non-local continuum poro-damage mechanics model for hydrofracturing of surface crevasses in grounded glaciers
| Autor: | Jeremy N. Bassis, Stephen Jiménez, Ravindra Duddu |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
geography
geography.geographical_feature_category Buoyancy 010504 meteorology & atmospheric sciences Glacier Mechanics engineering.material 010502 geochemistry & geophysics 01 natural sciences Iceberg Stress field Stress (mechanics) Crevasse Rheology Damage mechanics engineering Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Journal of Glaciology. 66:415-429 |
| ISSN: | 1727-5652 0022-1430 |
| DOI: | 10.1017/jog.2020.16 |
| Popis: | Hydrofracturing can enhance the depth to which crevasses propagate and, in some cases, allow full depth crevasse penetration and iceberg detachment. However, many existing crevasse models either do not fully account for the stress field driving the hydrofracture process and/or treat glacier ice as elastic, neglecting the non-linear viscous rheology. Here, we present a non-local continuum poro-damage mechanics (CPDM) model for hydrofracturing and implement it within a full Stokes finite element formulation. We use the CPDM model to simulate the propagation of water-filled crevasses in idealized grounded glaciers, and compare crevasse depths predicted by this model with those from linear elastic fracture mechanics (LEFM) and zero stress models. We find that the CPDM model is in good agreement with the LEFM model for isolated crevasses and with the zero stress model for closely-spaced crevasses, until the glacier approaches buoyancy. When the glacier approaches buoyancy, we find that the CPDM model does not allow the propagation of water-filled crevasses due to the much smaller size of the tensile stress region concentrated near the crevasse tip. Our study suggests that the combination of non-linear viscous and damage processes in ice near the tip of a water-filled crevasse can alter calving outcomes. |
| Databáze: | OpenAIRE |
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