Vulnerability of firn to hydrofracture: poromechanics modeling
On the Greenland Ice Sheet, hydrofracture connects the supraglacial and subglacial hydrologic systems, coupling surface runoff dynamics and ice velocity. In recent decades, the growth of low-permeability ice slabs in the wet snow zone has expanded Greenland's runoff zone, but observations sugge...
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Cambridge University Press
2024-01-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143024000479/type/journal_article |
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| author | Yue Meng Riley Culberg Ching-Yao Lai |
| author_facet | Yue Meng Riley Culberg Ching-Yao Lai |
| author_sort | Yue Meng |
| collection | DOAJ |
| description | On the Greenland Ice Sheet, hydrofracture connects the supraglacial and subglacial hydrologic systems, coupling surface runoff dynamics and ice velocity. In recent decades, the growth of low-permeability ice slabs in the wet snow zone has expanded Greenland's runoff zone, but observations suggest that surface-to-bed connections are rare, because meltwater drains through crevasses into the porous firn beneath ice slabs. However, there is little quantitative evidence confirming the absence of surface-to-bed fracture propagation. Here, we use poromechanics to investigate whether water-filled crevasses in ice slabs can propagate vertically through an underlying porous firn layer. Based on numerical simulations, we develop an analytical estimate of the water injection-induced effective stress in the firn given the water level in the crevasse, ice slab thickness, and firn properties. We find that the firn layer substantially reduces the system's vulnerability to hydrofracture because much of the hydrostatic stress is accommodated by a change in pore pressure, rather than being transmitted to the solid skeleton. This result suggests that surface-to-bed hydrofracture will not occur in ice slab regions until all pore space proximal to the initial flaw has been filled with solid ice. |
| format | Article |
| id | doaj-art-090fe9cf44284f4fb5f9ab1cae007eda |
| institution | Kabale University |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj-art-090fe9cf44284f4fb5f9ab1cae007eda2025-01-16T21:51:48ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2024.47Vulnerability of firn to hydrofracture: poromechanics modelingYue Meng0https://orcid.org/0000-0001-7623-2228Riley Culberg1https://orcid.org/0000-0002-4460-2359Ching-Yao Lai2Department of Geophysics, Stanford University, Stanford, CA, USA Department of Geosciences, Princeton University, Princeton, NJ, USADepartment of Geosciences, Princeton University, Princeton, NJ, USA Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USADepartment of Geophysics, Stanford University, Stanford, CA, USA Department of Geosciences, Princeton University, Princeton, NJ, USAOn the Greenland Ice Sheet, hydrofracture connects the supraglacial and subglacial hydrologic systems, coupling surface runoff dynamics and ice velocity. In recent decades, the growth of low-permeability ice slabs in the wet snow zone has expanded Greenland's runoff zone, but observations suggest that surface-to-bed connections are rare, because meltwater drains through crevasses into the porous firn beneath ice slabs. However, there is little quantitative evidence confirming the absence of surface-to-bed fracture propagation. Here, we use poromechanics to investigate whether water-filled crevasses in ice slabs can propagate vertically through an underlying porous firn layer. Based on numerical simulations, we develop an analytical estimate of the water injection-induced effective stress in the firn given the water level in the crevasse, ice slab thickness, and firn properties. We find that the firn layer substantially reduces the system's vulnerability to hydrofracture because much of the hydrostatic stress is accommodated by a change in pore pressure, rather than being transmitted to the solid skeleton. This result suggests that surface-to-bed hydrofracture will not occur in ice slab regions until all pore space proximal to the initial flaw has been filled with solid ice.https://www.cambridge.org/core/product/identifier/S0022143024000479/type/journal_articleGlacier hydrologyglacier mechanicsice-sheet mass balancepolar firn |
| spellingShingle | Yue Meng Riley Culberg Ching-Yao Lai Vulnerability of firn to hydrofracture: poromechanics modeling Journal of Glaciology Glacier hydrology glacier mechanics ice-sheet mass balance polar firn |
| title | Vulnerability of firn to hydrofracture: poromechanics modeling |
| title_full | Vulnerability of firn to hydrofracture: poromechanics modeling |
| title_fullStr | Vulnerability of firn to hydrofracture: poromechanics modeling |
| title_full_unstemmed | Vulnerability of firn to hydrofracture: poromechanics modeling |
| title_short | Vulnerability of firn to hydrofracture: poromechanics modeling |
| title_sort | vulnerability of firn to hydrofracture poromechanics modeling |
| topic | Glacier hydrology glacier mechanics ice-sheet mass balance polar firn |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000479/type/journal_article |
| work_keys_str_mv | AT yuemeng vulnerabilityoffirntohydrofractureporomechanicsmodeling AT rileyculberg vulnerabilityoffirntohydrofractureporomechanicsmodeling AT chingyaolai vulnerabilityoffirntohydrofractureporomechanicsmodeling |