Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica
Mass changes of polar ice sheets have an important societal impact, because they affect global sea level. Estimating the current mass budget of ice sheets is equivalent to determining the balance between the surface mass gain through precipitation and the outflow across the grounding line. In Antarc...
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Language: | English |
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Universite Libre de Bruxelles
2014
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Online Access: | http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209217 https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/4/53a0e0a4-f580-44e8-88ef-5f9831244a07.txt https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/1/696ecfdb-b06f-44cc-bf2d-cc45ac7f950a.txt |
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ftunivbruxelles:oai:dipot.ulb.ac.be:2013/209217 2023-05-15T13:37:29+02:00 Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica Callens, Denis Pattyn, Frank Tison, Jean-Louis Van Lipzig, Nicole P. M. Ross, Neil Camelbeeck, Thierry 2014-11-06 1 v. (xii, 75 p.) 2 full-text file(s): application/pdf | application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209217 https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/4/53a0e0a4-f580-44e8-88ef-5f9831244a07.txt https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/1/696ecfdb-b06f-44cc-bf2d-cc45ac7f950a.txt en eng Universite Libre de Bruxelles Université libre de Bruxelles, Faculté des Sciences – Géographie, Bruxelles local/bictel.ulb.ac.be:ULBetd-10302014-183435 local/ulbcat.ulb.ac.be:1083346 https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/4/53a0e0a4-f580-44e8-88ef-5f9831244a07.txt https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/1/696ecfdb-b06f-44cc-bf2d-cc45ac7f950a.txt http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209217 2 full-text file(s): info:eu-repo/semantics/openAccess | info:eu-repo/semantics/openAccess Géographie physique Sciences exactes et naturelles Geophysics -- Antarctica Mountains -- Antarctica Ice sheets -- Antarctica Géophysique -- Antarctique Montagnes -- Antarctique Inlandsis -- Antarctique ice flow modelling Antarctica Ice sheet mass balance geophysics info:eu-repo/semantics/doctoralThesis info:ulb-repo/semantics/doctoralThesis info:ulb-repo/semantics/openurl/vlink-dissertation 2014 ftunivbruxelles 2022-06-12T22:09:17Z Mass changes of polar ice sheets have an important societal impact, because they affect global sea level. Estimating the current mass budget of ice sheets is equivalent to determining the balance between the surface mass gain through precipitation and the outflow across the grounding line. In Antarctica, the latter is mainly governed by oceanic processes and outlet glacier dynamics. In this thesis, we assess the mass balance of a part of eastern DronningMaud Land via an input/output method. Input is given by recent surface accumulation estimations of the whole drainage basin. The outflow at the grounding line is determined from the radar data of a recent airborne survey and satellite-based velocities using a flow model of combined plug flow and simple shear. We estimate the regional mass balance in this area to be between 1.88±8.50 and 3.78±3.32 Gt a−1 depending on the surface mass balance (SMB) dataset used. This study also reveals that the plug flow assumption is acceptable at the grounding line of ice streams. The mass balance of drainage basins is governed by the dynamics of their outlet glaciers and more specifically the flow conditions at the grounding line. Thanks to an airborne radar survey we define the bed properties close to the grounding line of the West Ragnhild Glacier (WRG) in the Sør Rondane Mountains. Geometry and reflectivity analyses reveal that the bed of the last 65 km upstream of the grounding line is sediment covered and saturated with water. This setting promotes the dominance of basal motion leading to a change in the flow regime: in the interior flow is governed by internal deformation while its relative importance decreases to become driven by basal sliding. Subsequently we present the results of the reconstruction of the SMB across an ice rise through radar data and inverse modelling. The analysis demonstrates that atmospheric circulation was stable during the last millennium. Ice rises induce an orographic uplift of the atmospheric flow and therefore influence the pattern of the SMB ... Doctoral or Postdoctoral Thesis Antarc* Antarctica Antarctique* Dronning Maud Land Ice Sheet Inlandsis DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Dronning Maud Land Sør-Rondane ENVELOPE(25.000,25.000,-72.000,-72.000) Sør Rondane Mountains ENVELOPE(25.000,25.000,-72.000,-72.000) |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Géographie physique Sciences exactes et naturelles Geophysics -- Antarctica Mountains -- Antarctica Ice sheets -- Antarctica Géophysique -- Antarctique Montagnes -- Antarctique Inlandsis -- Antarctique ice flow modelling Antarctica Ice sheet mass balance geophysics |
spellingShingle |
Géographie physique Sciences exactes et naturelles Geophysics -- Antarctica Mountains -- Antarctica Ice sheets -- Antarctica Géophysique -- Antarctique Montagnes -- Antarctique Inlandsis -- Antarctique ice flow modelling Antarctica Ice sheet mass balance geophysics Callens, Denis Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica |
topic_facet |
Géographie physique Sciences exactes et naturelles Geophysics -- Antarctica Mountains -- Antarctica Ice sheets -- Antarctica Géophysique -- Antarctique Montagnes -- Antarctique Inlandsis -- Antarctique ice flow modelling Antarctica Ice sheet mass balance geophysics |
description |
Mass changes of polar ice sheets have an important societal impact, because they affect global sea level. Estimating the current mass budget of ice sheets is equivalent to determining the balance between the surface mass gain through precipitation and the outflow across the grounding line. In Antarctica, the latter is mainly governed by oceanic processes and outlet glacier dynamics. In this thesis, we assess the mass balance of a part of eastern DronningMaud Land via an input/output method. Input is given by recent surface accumulation estimations of the whole drainage basin. The outflow at the grounding line is determined from the radar data of a recent airborne survey and satellite-based velocities using a flow model of combined plug flow and simple shear. We estimate the regional mass balance in this area to be between 1.88±8.50 and 3.78±3.32 Gt a−1 depending on the surface mass balance (SMB) dataset used. This study also reveals that the plug flow assumption is acceptable at the grounding line of ice streams. The mass balance of drainage basins is governed by the dynamics of their outlet glaciers and more specifically the flow conditions at the grounding line. Thanks to an airborne radar survey we define the bed properties close to the grounding line of the West Ragnhild Glacier (WRG) in the Sør Rondane Mountains. Geometry and reflectivity analyses reveal that the bed of the last 65 km upstream of the grounding line is sediment covered and saturated with water. This setting promotes the dominance of basal motion leading to a change in the flow regime: in the interior flow is governed by internal deformation while its relative importance decreases to become driven by basal sliding. Subsequently we present the results of the reconstruction of the SMB across an ice rise through radar data and inverse modelling. The analysis demonstrates that atmospheric circulation was stable during the last millennium. Ice rises induce an orographic uplift of the atmospheric flow and therefore influence the pattern of the SMB ... |
author2 |
Pattyn, Frank Tison, Jean-Louis Van Lipzig, Nicole P. M. Ross, Neil Camelbeeck, Thierry |
format |
Doctoral or Postdoctoral Thesis |
author |
Callens, Denis |
author_facet |
Callens, Denis |
author_sort |
Callens, Denis |
title |
Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica |
title_short |
Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica |
title_full |
Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica |
title_fullStr |
Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica |
title_full_unstemmed |
Impact of improved basal and surface boundary conditions on the mass balance of the Sr Rondane Mountains glacial system, Dronning Maud Land, Antarctica |
title_sort |
impact of improved basal and surface boundary conditions on the mass balance of the sr rondane mountains glacial system, dronning maud land, antarctica |
publisher |
Universite Libre de Bruxelles |
publishDate |
2014 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209217 https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/4/53a0e0a4-f580-44e8-88ef-5f9831244a07.txt https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/1/696ecfdb-b06f-44cc-bf2d-cc45ac7f950a.txt |
long_lat |
ENVELOPE(25.000,25.000,-72.000,-72.000) ENVELOPE(25.000,25.000,-72.000,-72.000) |
geographic |
Dronning Maud Land Sør-Rondane Sør Rondane Mountains |
geographic_facet |
Dronning Maud Land Sør-Rondane Sør Rondane Mountains |
genre |
Antarc* Antarctica Antarctique* Dronning Maud Land Ice Sheet Inlandsis |
genre_facet |
Antarc* Antarctica Antarctique* Dronning Maud Land Ice Sheet Inlandsis |
op_relation |
local/bictel.ulb.ac.be:ULBetd-10302014-183435 local/ulbcat.ulb.ac.be:1083346 https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/4/53a0e0a4-f580-44e8-88ef-5f9831244a07.txt https://dipot.ulb.ac.be/dspace/bitstream/2013/209217/1/696ecfdb-b06f-44cc-bf2d-cc45ac7f950a.txt http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209217 |
op_rights |
2 full-text file(s): info:eu-repo/semantics/openAccess | info:eu-repo/semantics/openAccess |
_version_ |
1766092548073324544 |