دورية أكاديمية
Towards modelling of corrugation ridges at ice-sheet grounding lines
| العنوان: | Towards modelling of corrugation ridges at ice-sheet grounding lines |
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| المؤلفون: | K. A. Hogan, K. L. P. Warburton, A. G. C. Graham, J. A. Neufeld, D. R. Hewitt, J. A. Dowdeswell, R. D. Larter |
| المصدر: | The Cryosphere, Vol 17, Pp 2645-2664 (2023) |
| بيانات النشر: | Copernicus Publications, 2023. |
| سنة النشر: | 2023 |
| المجموعة: | LCC:Environmental sciences LCC:Geology |
| مصطلحات موضوعية: | Environmental sciences, GE1-350, Geology, QE1-996.5 |
| الوصف: | Improvements in the resolution of sea-floor mapping techniques have revealed extremely regular, sub-metre-scale ridge landforms produced by the tidal flexure of ice-shelf grounding lines as they retreated very rapidly (i.e. at rates of several kilometres per year). Guided by such novel sea-floor observations from Thwaites Glacier, West Antarctica, we present three mathematical models for the formation of these corrugation ridges at a tidally migrating grounding line (that is retreating at a constant rate), where each ridge is formed by either constant till flux to the grounding line, till extrusion from the grounding line, or the resuspension and transport of grains from the grounding-zone bed. We find that both till extrusion (squeezing out till like toothpaste as the ice sheet re-settles on the sea floor) and resuspension and transport of material can qualitatively reproduce regular, delicate ridges at a retreating grounding line, as described by sea-floor observations. By considering the known properties of subglacial sediments, we agree with existing schematic models that the most likely mechanism for ridge formation is till extrusion at each low-tide position, essentially preserving an imprint of the ice-sheet grounding line as it retreated. However, when realistic (shallow) bed slopes are used in the simulations, ridges start to overprint one another, suggesting that, to preserve the regular ridges that have been observed, grounding line retreat rates (driven by dynamic thinning?) may be even higher than previously thought. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 1994-0416 1994-0424 |
| Relation: | https://tc.copernicus.org/articles/17/2645/2023/tc-17-2645-2023.pdf; https://doaj.org/toc/1994-0416; https://doaj.org/toc/1994-0424 |
| DOI: | 10.5194/tc-17-2645-2023 |
| URL الوصول: | https://doaj.org/article/bfe705dfaee04880802c10530208f5a0 |
| رقم الأكسشن: | edsdoj.bfe705dfaee04880802c10530208f5a0 |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 19940416 19940424 |
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| DOI: | 10.5194/tc-17-2645-2023 |