Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica
On Dotson Ice Shelf, Antarctica, ice velocities derived from satellite image pairs and in-situ GPS measurements reveal an oscillating flow pattern that is correlated with tide height. The tidally-affected flow pattern is of limited extent, in an area near the Wunneberger Rock nunatak in the outflow...
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ftcopernicus:oai:publications.copernicus.org:egusphere121281 2024-09-15T17:42:31+00:00 Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica Collao-Barrios, Gabriela Scambos, Ted A. Wild, Christian T. Truffer, Martin Alley, Karen E. Pettit, Erin C. 2024-07-19 application/pdf https://doi.org/10.5194/egusphere-2024-1895 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1895/ eng eng doi:10.5194/egusphere-2024-1895 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1895/ eISSN: Text 2024 ftcopernicus https://doi.org/10.5194/egusphere-2024-1895 2024-07-26T00:08:26Z On Dotson Ice Shelf, Antarctica, ice velocities derived from satellite image pairs and in-situ GPS measurements reveal an oscillating flow pattern that is correlated with tide height. The tidally-affected flow pattern is of limited extent, in an area near the Wunneberger Rock nunatak in the outflow of Kohler Glacier. Comparing variations in the region’s flow velocity derived from a series of 16-day repeat-pass Landsat 8 image pairs spanning 2014–2020, and a 64-hour GPS record in 2022 with the CATS2008 and TPXO9 tide-height models, indicates a significant correlation between tidal uplift and the direction of ice-flow. During high-tide periods the ice-shelf flows in a true north direction, while at low-tide periods flow direction shifts towards the northeast, marking an approximately 40˚ change in flow direction. GPS measurements describe a continuous corkscrew-like motion of the ice-shelf surface, confirming the link between tide height and ice-flow direction. We attribute the observed pattern to tidally controlled changes of buttressing along the ice-shelf margins and the fin-like shape of Wunneberger Rock. This leads to a dual pattern: (i) fast flow across the grounding line of the tributary Kohler Glacier during high tides aligning with Wunneberger Rock’s summit ridge; and (ii) slow flow during low tide height facing its flanks. We suggest that the link between tides and ice dynamics is related to the rapid ice-shelf thinning in the area. In light of the continued thinning of ice shelves surrounding Antarctica, we anticipate similar variations in flow direction and speed arising from changes in tidal influence on buttressing from pinning points and grounding zones. Text Antarc* Antarctica Dotson Ice Shelf Ice Shelf Ice Shelves Kohler Glacier West Antarctica Copernicus Publications: E-Journals |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
On Dotson Ice Shelf, Antarctica, ice velocities derived from satellite image pairs and in-situ GPS measurements reveal an oscillating flow pattern that is correlated with tide height. The tidally-affected flow pattern is of limited extent, in an area near the Wunneberger Rock nunatak in the outflow of Kohler Glacier. Comparing variations in the region’s flow velocity derived from a series of 16-day repeat-pass Landsat 8 image pairs spanning 2014–2020, and a 64-hour GPS record in 2022 with the CATS2008 and TPXO9 tide-height models, indicates a significant correlation between tidal uplift and the direction of ice-flow. During high-tide periods the ice-shelf flows in a true north direction, while at low-tide periods flow direction shifts towards the northeast, marking an approximately 40˚ change in flow direction. GPS measurements describe a continuous corkscrew-like motion of the ice-shelf surface, confirming the link between tide height and ice-flow direction. We attribute the observed pattern to tidally controlled changes of buttressing along the ice-shelf margins and the fin-like shape of Wunneberger Rock. This leads to a dual pattern: (i) fast flow across the grounding line of the tributary Kohler Glacier during high tides aligning with Wunneberger Rock’s summit ridge; and (ii) slow flow during low tide height facing its flanks. We suggest that the link between tides and ice dynamics is related to the rapid ice-shelf thinning in the area. In light of the continued thinning of ice shelves surrounding Antarctica, we anticipate similar variations in flow direction and speed arising from changes in tidal influence on buttressing from pinning points and grounding zones. |
format |
Text |
author |
Collao-Barrios, Gabriela Scambos, Ted A. Wild, Christian T. Truffer, Martin Alley, Karen E. Pettit, Erin C. |
spellingShingle |
Collao-Barrios, Gabriela Scambos, Ted A. Wild, Christian T. Truffer, Martin Alley, Karen E. Pettit, Erin C. Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica |
author_facet |
Collao-Barrios, Gabriela Scambos, Ted A. Wild, Christian T. Truffer, Martin Alley, Karen E. Pettit, Erin C. |
author_sort |
Collao-Barrios, Gabriela |
title |
Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica |
title_short |
Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica |
title_full |
Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica |
title_fullStr |
Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica |
title_full_unstemmed |
Tidal influence on flow dynamics of Dotson Ice Shelf, West Antarctica |
title_sort |
tidal influence on flow dynamics of dotson ice shelf, west antarctica |
publishDate |
2024 |
url |
https://doi.org/10.5194/egusphere-2024-1895 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1895/ |
genre |
Antarc* Antarctica Dotson Ice Shelf Ice Shelf Ice Shelves Kohler Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Dotson Ice Shelf Ice Shelf Ice Shelves Kohler Glacier West Antarctica |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2024-1895 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1895/ |
op_doi |
https://doi.org/10.5194/egusphere-2024-1895 |
_version_ |
1810489122631974912 |