Transition of flow regime along a marine-terminating outlet glacier in East Antarctica
International audience We present results of a multi-methodological approach to characterize the flow regime of West Ragnhild Glacier, the widest glacier in Dronning Maud Land, Antarctica. A new airborne radar survey points to substantially thicker ice (>2000 m) than previously thought. With a di...
Published in: | The Cryosphere |
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Main Authors: | , , , , , |
Other Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2014
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Subjects: | |
Online Access: | https://hal.science/hal-01025406 https://doi.org/10.5194/tc-8-867-2014 |
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ftunigrenoble:oai:HAL:hal-01025406v1 |
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openpolar |
institution |
Open Polar |
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Université Grenoble Alpes: HAL |
op_collection_id |
ftunigrenoble |
language |
English |
topic |
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
spellingShingle |
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology Callens, Dorothée, D. Matsuoka, K. Steinhage, D. Smith, B. Witrant, Emmanuel Pattyn, F. Transition of flow regime along a marine-terminating outlet glacier in East Antarctica |
topic_facet |
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
description |
International audience We present results of a multi-methodological approach to characterize the flow regime of West Ragnhild Glacier, the widest glacier in Dronning Maud Land, Antarctica. A new airborne radar survey points to substantially thicker ice (>2000 m) than previously thought. With a discharge estimate of 13–14 Gt yr−1, West Ragnhild Glacier thus becomes of the three major outlet glaciers in Dronning Maud Land. Its bed topography is distinct between the upstream and downstream section: in the downstream section (<65 km upstream of the grounding line), the glacier overlies a wide and flat basin well below the sea level, while the upstream region is more mountainous. Spectral analysis of the bed topography also reveals this clear contrast and suggests that the downstream area is sediment covered. Furthermore, bed-returned power varies by 30 dB within 20 km near the bed flatness transition, suggesting that the water content at bed/ice interface increases over a short distance downstream, hence pointing to water-rich sediment. Ice flow speed observed in the downstream part of the glacier (~250 m yr−1) can only be explained through very low basal friction, leading to a substantial amount of basal sliding in the downstream 65 km of the glacier. All the above lines of evidence (sediment bed, wetness and basal motion) and the relatively flat grounding zone give the potential for West Ragnhild Glacier to be more sensitive to external forcing compared to other major outlet glaciers in this region, which are more stable due to their bed geometry (e.g. Shirase Glacier). |
author2 |
Laboratoire de Glaciologie Bruxelles Université libre de Bruxelles (ULB) Norwegian Polar Institute Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association Applied Physics Laboratory Seattle (APL-UW) University of Washington Seattle GIPSA - Systèmes linéaires et robustesse (GIPSA-SLR) Département Automatique (GIPSA-DA) Grenoble Images Parole Signal Automatique (GIPSA-lab) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Callens, Dorothée, D. Matsuoka, K. Steinhage, D. Smith, B. Witrant, Emmanuel Pattyn, F. |
author_facet |
Callens, Dorothée, D. Matsuoka, K. Steinhage, D. Smith, B. Witrant, Emmanuel Pattyn, F. |
author_sort |
Callens, Dorothée, D. |
title |
Transition of flow regime along a marine-terminating outlet glacier in East Antarctica |
title_short |
Transition of flow regime along a marine-terminating outlet glacier in East Antarctica |
title_full |
Transition of flow regime along a marine-terminating outlet glacier in East Antarctica |
title_fullStr |
Transition of flow regime along a marine-terminating outlet glacier in East Antarctica |
title_full_unstemmed |
Transition of flow regime along a marine-terminating outlet glacier in East Antarctica |
title_sort |
transition of flow regime along a marine-terminating outlet glacier in east antarctica |
publisher |
HAL CCSD |
publishDate |
2014 |
url |
https://hal.science/hal-01025406 https://doi.org/10.5194/tc-8-867-2014 |
long_lat |
ENVELOPE(39.000,39.000,-70.333,-70.333) |
geographic |
East Antarctica Dronning Maud Land Shirase Glacier |
geographic_facet |
East Antarctica Dronning Maud Land Shirase Glacier |
genre |
Antarc* Antarctica Dronning Maud Land East Antarctica Shirase Glacier The Cryosphere |
genre_facet |
Antarc* Antarctica Dronning Maud Land East Antarctica Shirase Glacier The Cryosphere |
op_source |
ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.science/hal-01025406 The Cryosphere, 2014, 8, pp.867-875. ⟨10.5194/tc-8-867-2014⟩ https://tc.copernicus.org/articles/8/867/2014/ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-8-867-2014 hal-01025406 https://hal.science/hal-01025406 doi:10.5194/tc-8-867-2014 |
op_doi |
https://doi.org/10.5194/tc-8-867-2014 |
container_title |
The Cryosphere |
container_volume |
8 |
container_issue |
3 |
container_start_page |
867 |
op_container_end_page |
875 |
_version_ |
1798843750637633536 |
spelling |
ftunigrenoble:oai:HAL:hal-01025406v1 2024-05-12T07:53:38+00:00 Transition of flow regime along a marine-terminating outlet glacier in East Antarctica Callens, Dorothée, D. Matsuoka, K. Steinhage, D. Smith, B. Witrant, Emmanuel Pattyn, F. Laboratoire de Glaciologie Bruxelles Université libre de Bruxelles (ULB) Norwegian Polar Institute Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association Applied Physics Laboratory Seattle (APL-UW) University of Washington Seattle GIPSA - Systèmes linéaires et robustesse (GIPSA-SLR) Département Automatique (GIPSA-DA) Grenoble Images Parole Signal Automatique (GIPSA-lab) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) 2014 https://hal.science/hal-01025406 https://doi.org/10.5194/tc-8-867-2014 en eng HAL CCSD Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-8-867-2014 hal-01025406 https://hal.science/hal-01025406 doi:10.5194/tc-8-867-2014 ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.science/hal-01025406 The Cryosphere, 2014, 8, pp.867-875. ⟨10.5194/tc-8-867-2014⟩ https://tc.copernicus.org/articles/8/867/2014/ [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology info:eu-repo/semantics/article Journal articles 2014 ftunigrenoble https://doi.org/10.5194/tc-8-867-2014 2024-04-18T04:31:16Z International audience We present results of a multi-methodological approach to characterize the flow regime of West Ragnhild Glacier, the widest glacier in Dronning Maud Land, Antarctica. A new airborne radar survey points to substantially thicker ice (>2000 m) than previously thought. With a discharge estimate of 13–14 Gt yr−1, West Ragnhild Glacier thus becomes of the three major outlet glaciers in Dronning Maud Land. Its bed topography is distinct between the upstream and downstream section: in the downstream section (<65 km upstream of the grounding line), the glacier overlies a wide and flat basin well below the sea level, while the upstream region is more mountainous. Spectral analysis of the bed topography also reveals this clear contrast and suggests that the downstream area is sediment covered. Furthermore, bed-returned power varies by 30 dB within 20 km near the bed flatness transition, suggesting that the water content at bed/ice interface increases over a short distance downstream, hence pointing to water-rich sediment. Ice flow speed observed in the downstream part of the glacier (~250 m yr−1) can only be explained through very low basal friction, leading to a substantial amount of basal sliding in the downstream 65 km of the glacier. All the above lines of evidence (sediment bed, wetness and basal motion) and the relatively flat grounding zone give the potential for West Ragnhild Glacier to be more sensitive to external forcing compared to other major outlet glaciers in this region, which are more stable due to their bed geometry (e.g. Shirase Glacier). Article in Journal/Newspaper Antarc* Antarctica Dronning Maud Land East Antarctica Shirase Glacier The Cryosphere Université Grenoble Alpes: HAL East Antarctica Dronning Maud Land Shirase Glacier ENVELOPE(39.000,39.000,-70.333,-70.333) The Cryosphere 8 3 867 875 |