The effect of melt-channel geometry on ice-shelf flow
Basal channels are incised troughs formed by elevated melt beneath ice shelves. Channels often coincide with shear margins, suggesting feedbacks between channel formation and shear. However, the effect of channel position and shape on ice-shelf flow has not been systematically explored. We use a mod...
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Cambridge University Press
2025-01-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S002214302500036X/type/journal_article |
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| author | David A. Lilien Karen E. Alley Richard B. Alley |
| author_facet | David A. Lilien Karen E. Alley Richard B. Alley |
| author_sort | David A. Lilien |
| collection | DOAJ |
| description | Basal channels are incised troughs formed by elevated melt beneath ice shelves. Channels often coincide with shear margins, suggesting feedbacks between channel formation and shear. However, the effect of channel position and shape on ice-shelf flow has not been systematically explored. We use a model to show that, as expected, channels concentrate deformation and increase ice-shelf flow speeds, in some cases by over 100% at the ice-shelf center and over 80% at the grounding line. The resulting increase in shear can cause stresses around the channels to exceed the threshold for failure, suggesting that rifting, calving and retreat might result. However, channels have different effects depending on their width, depth and position on an ice shelf. Channels in areas where ice shelves are spreading freely have little effect on ice flow, and even channels in confined regions of the shelf do not necessarily alter flow significantly. Nevertheless, if located in areas of vulnerability, particularly in the shear margins near the grounding line, melt channels may alter flow in a way that could lead to catastrophic ice-shelf breakup by mechanically separating shelves from their embayments. |
| format | Article |
| id | doaj-art-e785bb50725d419b9cd680a4cba22236 |
| institution | DOAJ |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj-art-e785bb50725d419b9cd680a4cba222362025-08-20T03:21:32ZengCambridge University PressJournal of Glaciology0022-14301727-56522025-01-017110.1017/jog.2025.36The effect of melt-channel geometry on ice-shelf flowDavid A. Lilien0https://orcid.org/0000-0001-8667-8020Karen E. Alley1https://orcid.org/0000-0003-0358-3806Richard B. Alley2https://orcid.org/0000-0003-1833-0115Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, IN, USACentre for Earth Observation Science, University of Manitoba, Winnipeg, MB, CanadaDepartment of Geosciences, and Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA, USABasal channels are incised troughs formed by elevated melt beneath ice shelves. Channels often coincide with shear margins, suggesting feedbacks between channel formation and shear. However, the effect of channel position and shape on ice-shelf flow has not been systematically explored. We use a model to show that, as expected, channels concentrate deformation and increase ice-shelf flow speeds, in some cases by over 100% at the ice-shelf center and over 80% at the grounding line. The resulting increase in shear can cause stresses around the channels to exceed the threshold for failure, suggesting that rifting, calving and retreat might result. However, channels have different effects depending on their width, depth and position on an ice shelf. Channels in areas where ice shelves are spreading freely have little effect on ice flow, and even channels in confined regions of the shelf do not necessarily alter flow significantly. Nevertheless, if located in areas of vulnerability, particularly in the shear margins near the grounding line, melt channels may alter flow in a way that could lead to catastrophic ice-shelf breakup by mechanically separating shelves from their embayments.https://www.cambridge.org/core/product/identifier/S002214302500036X/type/journal_articleglaciological model experimentsice dynamicsice/ocean interactionsice shelvesmelt-basal |
| spellingShingle | David A. Lilien Karen E. Alley Richard B. Alley The effect of melt-channel geometry on ice-shelf flow Journal of Glaciology glaciological model experiments ice dynamics ice/ocean interactions ice shelves melt-basal |
| title | The effect of melt-channel geometry on ice-shelf flow |
| title_full | The effect of melt-channel geometry on ice-shelf flow |
| title_fullStr | The effect of melt-channel geometry on ice-shelf flow |
| title_full_unstemmed | The effect of melt-channel geometry on ice-shelf flow |
| title_short | The effect of melt-channel geometry on ice-shelf flow |
| title_sort | effect of melt channel geometry on ice shelf flow |
| topic | glaciological model experiments ice dynamics ice/ocean interactions ice shelves melt-basal |
| url | https://www.cambridge.org/core/product/identifier/S002214302500036X/type/journal_article |
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