Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing
The majority of Antarctic ice shelves are bounded by grounded ice rises. These ice rises exhibit local flow fields that partially oppose the flow of the surrounding ice shelves. Formation of ice rises is accompanied by a characteristic upward-arching internal stratigraphy (“Raymond arches”), whose g...
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ftcopernicus:oai:publications.copernicus.org:tc74315 2023-05-15T13:55:28+02:00 Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing Schannwell, Clemens Drews, Reinhard Ehlers, Todd A. Eisen, Olaf Mayer, Christoph Gillet-Chaulet, Fabien 2019-10-14 application/pdf https://doi.org/10.5194/tc-13-2673-2019 https://tc.copernicus.org/articles/13/2673/2019/ eng eng doi:10.5194/tc-13-2673-2019 https://tc.copernicus.org/articles/13/2673/2019/ eISSN: 1994-0424 Text 2019 ftcopernicus https://doi.org/10.5194/tc-13-2673-2019 2020-07-20T16:22:37Z The majority of Antarctic ice shelves are bounded by grounded ice rises. These ice rises exhibit local flow fields that partially oppose the flow of the surrounding ice shelves. Formation of ice rises is accompanied by a characteristic upward-arching internal stratigraphy (“Raymond arches”), whose geometry can be analysed to infer information about past ice-sheet changes in areas where other archives such as rock outcrops are missing. Here we present an improved modelling framework to study ice-rise evolution using a satellite-velocity calibrated, isothermal, and isotropic 3-D full-Stokes model including grounding-line dynamics at the required mesh resolution ( < 500 m). This overcomes limitations of previous studies where ice-rise modelling has been restricted to 2-D and excluded the coupling between the ice shelf and ice rise. We apply the model to the Ekström Ice Shelf, Antarctica, containing two ice rises. Our simulations investigate the effect of surface mass balance and ocean perturbations onto ice-rise divide position and interpret possible resulting unique Raymond arch geometries. Our results show that changes in the surface mass balance result in immediate and sustained divide migration ( >2.0 m yr −1 ) of up to 3.5 km. In contrast, instantaneous ice-shelf disintegration causes a short-lived and delayed (by 60–100 years) response of smaller magnitude ( <0.75 m yr −1 ). The model tracks migration of a triple junction and synchronous ice-divide migration in both ice rises with similar magnitude but differing rates. The model is suitable for glacial/interglacial simulations on the catchment scale, providing the next step forward to unravel the ice-dynamic history stored in ice rises all around Antarctica. Text Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Copernicus Publications: E-Journals Antarctic Ekström Ice Shelf ENVELOPE(-8.000,-8.000,-71.000,-71.000) The Cryosphere 13 10 2673 2691 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
The majority of Antarctic ice shelves are bounded by grounded ice rises. These ice rises exhibit local flow fields that partially oppose the flow of the surrounding ice shelves. Formation of ice rises is accompanied by a characteristic upward-arching internal stratigraphy (“Raymond arches”), whose geometry can be analysed to infer information about past ice-sheet changes in areas where other archives such as rock outcrops are missing. Here we present an improved modelling framework to study ice-rise evolution using a satellite-velocity calibrated, isothermal, and isotropic 3-D full-Stokes model including grounding-line dynamics at the required mesh resolution ( < 500 m). This overcomes limitations of previous studies where ice-rise modelling has been restricted to 2-D and excluded the coupling between the ice shelf and ice rise. We apply the model to the Ekström Ice Shelf, Antarctica, containing two ice rises. Our simulations investigate the effect of surface mass balance and ocean perturbations onto ice-rise divide position and interpret possible resulting unique Raymond arch geometries. Our results show that changes in the surface mass balance result in immediate and sustained divide migration ( >2.0 m yr −1 ) of up to 3.5 km. In contrast, instantaneous ice-shelf disintegration causes a short-lived and delayed (by 60–100 years) response of smaller magnitude ( <0.75 m yr −1 ). The model tracks migration of a triple junction and synchronous ice-divide migration in both ice rises with similar magnitude but differing rates. The model is suitable for glacial/interglacial simulations on the catchment scale, providing the next step forward to unravel the ice-dynamic history stored in ice rises all around Antarctica. |
format |
Text |
author |
Schannwell, Clemens Drews, Reinhard Ehlers, Todd A. Eisen, Olaf Mayer, Christoph Gillet-Chaulet, Fabien |
spellingShingle |
Schannwell, Clemens Drews, Reinhard Ehlers, Todd A. Eisen, Olaf Mayer, Christoph Gillet-Chaulet, Fabien Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing |
author_facet |
Schannwell, Clemens Drews, Reinhard Ehlers, Todd A. Eisen, Olaf Mayer, Christoph Gillet-Chaulet, Fabien |
author_sort |
Schannwell, Clemens |
title |
Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing |
title_short |
Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing |
title_full |
Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing |
title_fullStr |
Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing |
title_full_unstemmed |
Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing |
title_sort |
kinematic response of ice-rise divides to changes in ocean and atmosphere forcing |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-2673-2019 https://tc.copernicus.org/articles/13/2673/2019/ |
long_lat |
ENVELOPE(-8.000,-8.000,-71.000,-71.000) |
geographic |
Antarctic Ekström Ice Shelf |
geographic_facet |
Antarctic Ekström Ice Shelf |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-13-2673-2019 https://tc.copernicus.org/articles/13/2673/2019/ |
op_doi |
https://doi.org/10.5194/tc-13-2673-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
10 |
container_start_page |
2673 |
op_container_end_page |
2691 |
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1766262108231565312 |