Ice‐shelf basal melt channels stabilized by secondary flow
Ice-shelf basal channels form due to concentrated submarine melting. They are present in many Antarctic ice shelves and can reduce ice-shelf structural integrity, potentially destabilizing ice shelves by full-depth incision. Here, we describe the viscous ice response to a basal channel - secondary fl...
| Published in: | Geophysical Research Letters |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
2021
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| Subjects: | |
| Online Access: | http://nora.nerc.ac.uk/id/eprint/531273/ https://nora.nerc.ac.uk/id/eprint/531273/1/2021GL094872.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL094872 |
| Summary: | Ice-shelf basal channels form due to concentrated submarine melting. They are present in many Antarctic ice shelves and can reduce ice-shelf structural integrity, potentially destabilizing ice shelves by full-depth incision. Here, we describe the viscous ice response to a basal channel - secondary flow - which acts perpendicular to the channel axis and is induced by gradients in ice thickness. We use a full-Stokes ice-flow model to systematically assess the transient evolution of a basal channel in the presence of melting. Secondary flow increases with channel size and reduces the rate of channel incision, such that linear extrapolation or the Shallow-Shelf Approximation cannot project future channel evolution. For thick ice shelves (> 600 m) secondary flow potentially stabilizes the channel, but is insufficient to significantly delay breakthrough for thinner ice (< 400 m). Using synthetic data, we assess the impact of secondary flow when inferring basal-channel melt rates from satellite observations. |
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