Spatial complexity of ice flow across the Antarctic Ice Sheet
Fast-flowing ice streams carry ice from the interior of the Antarctic Ice Sheet towards the coast. Understanding how ice-stream tributaries operate and how networks of them evolve is essential for developing reliable models of the ice sheet's response to climate change. A particular challenge i...
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Online Access: | https://eprints.whiterose.ac.uk/92053/ https://eprints.whiterose.ac.uk/92053/9/Spatial%20complexity.pdf https://doi.org/10.1038/ngeo2532 |
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ftleedsuniv:oai:eprints.whiterose.ac.uk:92053 2023-05-15T13:55:00+02:00 Spatial complexity of ice flow across the Antarctic Ice Sheet Ng, F.S.L. 2015-09-16 text https://eprints.whiterose.ac.uk/92053/ https://eprints.whiterose.ac.uk/92053/9/Spatial%20complexity.pdf https://doi.org/10.1038/ngeo2532 en eng Nature Publishing Group https://eprints.whiterose.ac.uk/92053/9/Spatial%20complexity.pdf Ng, F.S.L. (2015) Spatial complexity of ice flow across the Antarctic Ice Sheet. Nature Geoscience, 8. 847 -850. ISSN 1752-0894 Article PeerReviewed 2015 ftleedsuniv https://doi.org/10.1038/ngeo2532 2023-01-30T21:36:52Z Fast-flowing ice streams carry ice from the interior of the Antarctic Ice Sheet towards the coast. Understanding how ice-stream tributaries operate and how networks of them evolve is essential for developing reliable models of the ice sheet's response to climate change. A particular challenge is to unravel the spatial complexity of flow within and across tributary networks. Here I define a measure of planimetric flow convergence, which can be calculated from satellite measurements of the ice sheet's surface velocity, to explore this complexity. The convergence map of Antarctica clarifies how tributaries draw ice from its interior. The map also reveals curvilinear zones of convergence along lateral shear margins of streaming, and abundant ripples associated with nonlinear ice rheology and changes in bed topography and friction. Convergence on ice-stream tributaries and their feeding zones is uneven and interspersed with divergence. For individual drainage basins, as well as the ice sheet as a whole, fast flow cannot converge or diverge as much as slow flow. I therefore deduce that flow in the ice-stream networks is subject to mechanical regulation that limits flow-orthonormal strain rates. These findings provide targets for ice-sheet simulations and motivate more research into the origin and dynamics of tributarization. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet White Rose Research Online (Universities of Leeds, Sheffield & York) Antarctic The Antarctic Nature Geoscience 8 11 847 850 |
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White Rose Research Online (Universities of Leeds, Sheffield & York) |
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English |
description |
Fast-flowing ice streams carry ice from the interior of the Antarctic Ice Sheet towards the coast. Understanding how ice-stream tributaries operate and how networks of them evolve is essential for developing reliable models of the ice sheet's response to climate change. A particular challenge is to unravel the spatial complexity of flow within and across tributary networks. Here I define a measure of planimetric flow convergence, which can be calculated from satellite measurements of the ice sheet's surface velocity, to explore this complexity. The convergence map of Antarctica clarifies how tributaries draw ice from its interior. The map also reveals curvilinear zones of convergence along lateral shear margins of streaming, and abundant ripples associated with nonlinear ice rheology and changes in bed topography and friction. Convergence on ice-stream tributaries and their feeding zones is uneven and interspersed with divergence. For individual drainage basins, as well as the ice sheet as a whole, fast flow cannot converge or diverge as much as slow flow. I therefore deduce that flow in the ice-stream networks is subject to mechanical regulation that limits flow-orthonormal strain rates. These findings provide targets for ice-sheet simulations and motivate more research into the origin and dynamics of tributarization. |
format |
Article in Journal/Newspaper |
author |
Ng, F.S.L. |
spellingShingle |
Ng, F.S.L. Spatial complexity of ice flow across the Antarctic Ice Sheet |
author_facet |
Ng, F.S.L. |
author_sort |
Ng, F.S.L. |
title |
Spatial complexity of ice flow across the Antarctic Ice Sheet |
title_short |
Spatial complexity of ice flow across the Antarctic Ice Sheet |
title_full |
Spatial complexity of ice flow across the Antarctic Ice Sheet |
title_fullStr |
Spatial complexity of ice flow across the Antarctic Ice Sheet |
title_full_unstemmed |
Spatial complexity of ice flow across the Antarctic Ice Sheet |
title_sort |
spatial complexity of ice flow across the antarctic ice sheet |
publisher |
Nature Publishing Group |
publishDate |
2015 |
url |
https://eprints.whiterose.ac.uk/92053/ https://eprints.whiterose.ac.uk/92053/9/Spatial%20complexity.pdf https://doi.org/10.1038/ngeo2532 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_relation |
https://eprints.whiterose.ac.uk/92053/9/Spatial%20complexity.pdf Ng, F.S.L. (2015) Spatial complexity of ice flow across the Antarctic Ice Sheet. Nature Geoscience, 8. 847 -850. ISSN 1752-0894 |
op_doi |
https://doi.org/10.1038/ngeo2532 |
container_title |
Nature Geoscience |
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8 |
container_issue |
11 |
container_start_page |
847 |
op_container_end_page |
850 |
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1766261219683991552 |