Theoretical stability of ice shelf basal crevasses with a vertical temperature profile
Basal crevasses threaten the stability of ice shelves through the potential to form rifts and calve icebergs. Furthermore, it is important to determine the dependence of crevasse stability on temperature due to large vertical temperature variations on ice shelves. In this work, considering the verti...
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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/S0022143024000522/type/journal_article |
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| author | Niall Bennet Coffey Ching-Yao Lai Yongji Wang W. Roger Buck Trystan Surawy-Stepney Anna Elizabeth Hogg |
| author_facet | Niall Bennet Coffey Ching-Yao Lai Yongji Wang W. Roger Buck Trystan Surawy-Stepney Anna Elizabeth Hogg |
| author_sort | Niall Bennet Coffey |
| collection | DOAJ |
| description | Basal crevasses threaten the stability of ice shelves through the potential to form rifts and calve icebergs. Furthermore, it is important to determine the dependence of crevasse stability on temperature due to large vertical temperature variations on ice shelves. In this work, considering the vertical temperature profile through ice viscosity, we compare (1) the theoretical crack depths and (2) the threshold stress causing the transition from basal crevasses to full thickness fractures in several fracture theories. In the Zero Stress approximation, the depth-integrated force at the crevassed and non-crevassed location are unbalanced, violating the volume-integrated Stokes equation. By incorporating a Horizontal Force Balance (HFB) argument, recent work showed analytically that the threshold stress for rift initiation is only half of that predicted by the Zero Stress approximation. We generalize the HFB theory to show that while the temperature profile influences crack depths, the threshold rifting stress is insensitive to temperature. We compare with observations and find that HFB best matches observed rifts. Using HFB instead of Zero Stress for cracks in an ice-sheet model would substantially enlarge the predicted fracture depth, reduce the threshold rifting stress and potentially increase the projected rate of ice shelf mass loss. |
| format | Article |
| id | doaj-art-c0760c737d2342bfb3bfffbfadad3446 |
| institution | Kabale University |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Cambridge University Press |
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| series | Journal of Glaciology |
| spelling | doaj-art-c0760c737d2342bfb3bfffbfadad34462025-01-16T21:48:54ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2024.52Theoretical stability of ice shelf basal crevasses with a vertical temperature profileNiall Bennet Coffey0https://orcid.org/0000-0002-3368-8839Ching-Yao Lai1Yongji Wang2W. Roger Buck3Trystan Surawy-Stepney4Anna Elizabeth Hogg5Department of Geophysics, Stanford University, Stanford, CA, USA Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, USADepartment of Geophysics, Stanford University, Stanford, CA, USA Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, USA Department of Geosciences, Princeton University, Princeton, NJ, USADepartment of Geophysics, Stanford University, Stanford, CA, USA Department of Geosciences, Princeton University, Princeton, NJ, USA Department of Mathematics, New York University, New York, NY, USALamont-Doherty Earth Observatory of Columbia University, New York, NY, USASchool of Earth and Environment, University of Leeds, Leeds, UKSchool of Earth and Environment, University of Leeds, Leeds, UKBasal crevasses threaten the stability of ice shelves through the potential to form rifts and calve icebergs. Furthermore, it is important to determine the dependence of crevasse stability on temperature due to large vertical temperature variations on ice shelves. In this work, considering the vertical temperature profile through ice viscosity, we compare (1) the theoretical crack depths and (2) the threshold stress causing the transition from basal crevasses to full thickness fractures in several fracture theories. In the Zero Stress approximation, the depth-integrated force at the crevassed and non-crevassed location are unbalanced, violating the volume-integrated Stokes equation. By incorporating a Horizontal Force Balance (HFB) argument, recent work showed analytically that the threshold stress for rift initiation is only half of that predicted by the Zero Stress approximation. We generalize the HFB theory to show that while the temperature profile influences crack depths, the threshold rifting stress is insensitive to temperature. We compare with observations and find that HFB best matches observed rifts. Using HFB instead of Zero Stress for cracks in an ice-sheet model would substantially enlarge the predicted fracture depth, reduce the threshold rifting stress and potentially increase the projected rate of ice shelf mass loss.https://www.cambridge.org/core/product/identifier/S0022143024000522/type/journal_articlecalvingcrevassesice shelves |
| spellingShingle | Niall Bennet Coffey Ching-Yao Lai Yongji Wang W. Roger Buck Trystan Surawy-Stepney Anna Elizabeth Hogg Theoretical stability of ice shelf basal crevasses with a vertical temperature profile Journal of Glaciology calving crevasses ice shelves |
| title | Theoretical stability of ice shelf basal crevasses with a vertical temperature profile |
| title_full | Theoretical stability of ice shelf basal crevasses with a vertical temperature profile |
| title_fullStr | Theoretical stability of ice shelf basal crevasses with a vertical temperature profile |
| title_full_unstemmed | Theoretical stability of ice shelf basal crevasses with a vertical temperature profile |
| title_short | Theoretical stability of ice shelf basal crevasses with a vertical temperature profile |
| title_sort | theoretical stability of ice shelf basal crevasses with a vertical temperature profile |
| topic | calving crevasses ice shelves |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000522/type/journal_article |
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