Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice
Microstructures from deep ice cores reflect the dynamic conditions of the drill location as well as the thermodynamic history of the drill site and catchment area in great detail. Ice core parameters (crystal lattice-preferred orientation (LPO), grain size, grain shape), mesostructures (visual strat...
Published in: | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |
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Online Access: | http://hdl.handle.net/10810/44038 https://doi.org/10.1098/rsta.2015.0347 |
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ftunivpaisvasco:oai:addi.ehu.es:10810/44038 2023-05-15T13:34:03+02:00 Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice Weikusat, I. Jansen, D. Binder, T. Eichler, J. Faria, S.H. Wilhelms, F. Kipfstuhl, S. Sheldon, S. Miller, H. Dahl-Jensen, D. Kleiner, T. 2017 http://hdl.handle.net/10810/44038 https://doi.org/10.1098/rsta.2015.0347 eng eng Royal Society info:eu-repo/grantAgreement/MINECO/RYC-2012-12167 ES/1PE/RYC-2012-12167 https://dx.doi.org/10.1098/rsta.2015.0347 Philosophical Transactions Of The Royal Society A-Mathematical Physical And Engineering Sciences 375(2086) : 20150347 (2017) 1364-503X http://hdl.handle.net/10810/44038 doi:10.1098/rsta.2015.0347 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-sa/3.0/en/ (c) 2016 The Author(s) Published by the Royal Society. All rights reserved. CC-BY-NC-SA info:eu-repo/semantics/article 2017 ftunivpaisvasco https://doi.org/10.1098/rsta.2015.0347 2022-03-10T16:38:46Z Microstructures from deep ice cores reflect the dynamic conditions of the drill location as well as the thermodynamic history of the drill site and catchment area in great detail. Ice core parameters (crystal lattice-preferred orientation (LPO), grain size, grain shape), mesostructures (visual stratigraphy) as well as borehole deformation were measured in a deep ice core drilled at Kohnen Station, Dronning Maud Land (DML), Antarctica. These observations are used to characterize the local dynamic setting and its rheological as well as microstructural effects at the EDML ice core drilling site (European Project for Ice Coring in Antarctica in DML). The results suggest a division of the core into five distinct sections, interpreted as the effects of changing deformation boundary conditions from triaxial deformation with horizontal extension to bedrock-parallel shear. Region 1 (uppermost approx. 450m depth) with still small macroscopic strain is dominated by compression of bubbles and strong strain and recrystallization localization. Region 2 (approx. 450-1700m depth) shows a girdle-type LPO with the girdle plane being perpendicular to grain elongations, which indicates triaxial deformation with dominating horizontal extension. In this region (approx. 1000m depth), the first subtle traces of shear deformation are observed in the shape-preferred orientation (SPO) by inclination of the grain elongation. Region 3 (approx. 1700-2030m depth) represents a transitional regime between triaxial deformation and dominance of shear, which becomes apparent in the progression of the girdle to a single maximum LPO and increasing obliqueness of grain elongations. The fully developed single maximum LPO in region 4 (approx. 2030-2385m depth) is an indicator of shear dominance. Region 5 (below approx. 2385m depth) is marked by signs of strong shear, such as strong SPO values of grain elongation and strong kink folding of visual layers. The details of structural observations are compared with results from a numerical ice sheet model ... Article in Journal/Newspaper Antarc* Antarctic Antarctica DML Dronning Maud Land ice core Ice Sheet ADDI: Repositorio Institucional de la Universidad del País Vasco (UPV) Antarctic Dronning Maud Land Kohnen ENVELOPE(0.000,0.000,-75.000,-75.000) Kohnen Station ENVELOPE(0.000,0.000,-75.000,-75.000) Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 375 2086 20150347 |
institution |
Open Polar |
collection |
ADDI: Repositorio Institucional de la Universidad del País Vasco (UPV) |
op_collection_id |
ftunivpaisvasco |
language |
English |
description |
Microstructures from deep ice cores reflect the dynamic conditions of the drill location as well as the thermodynamic history of the drill site and catchment area in great detail. Ice core parameters (crystal lattice-preferred orientation (LPO), grain size, grain shape), mesostructures (visual stratigraphy) as well as borehole deformation were measured in a deep ice core drilled at Kohnen Station, Dronning Maud Land (DML), Antarctica. These observations are used to characterize the local dynamic setting and its rheological as well as microstructural effects at the EDML ice core drilling site (European Project for Ice Coring in Antarctica in DML). The results suggest a division of the core into five distinct sections, interpreted as the effects of changing deformation boundary conditions from triaxial deformation with horizontal extension to bedrock-parallel shear. Region 1 (uppermost approx. 450m depth) with still small macroscopic strain is dominated by compression of bubbles and strong strain and recrystallization localization. Region 2 (approx. 450-1700m depth) shows a girdle-type LPO with the girdle plane being perpendicular to grain elongations, which indicates triaxial deformation with dominating horizontal extension. In this region (approx. 1000m depth), the first subtle traces of shear deformation are observed in the shape-preferred orientation (SPO) by inclination of the grain elongation. Region 3 (approx. 1700-2030m depth) represents a transitional regime between triaxial deformation and dominance of shear, which becomes apparent in the progression of the girdle to a single maximum LPO and increasing obliqueness of grain elongations. The fully developed single maximum LPO in region 4 (approx. 2030-2385m depth) is an indicator of shear dominance. Region 5 (below approx. 2385m depth) is marked by signs of strong shear, such as strong SPO values of grain elongation and strong kink folding of visual layers. The details of structural observations are compared with results from a numerical ice sheet model ... |
format |
Article in Journal/Newspaper |
author |
Weikusat, I. Jansen, D. Binder, T. Eichler, J. Faria, S.H. Wilhelms, F. Kipfstuhl, S. Sheldon, S. Miller, H. Dahl-Jensen, D. Kleiner, T. |
spellingShingle |
Weikusat, I. Jansen, D. Binder, T. Eichler, J. Faria, S.H. Wilhelms, F. Kipfstuhl, S. Sheldon, S. Miller, H. Dahl-Jensen, D. Kleiner, T. Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice |
author_facet |
Weikusat, I. Jansen, D. Binder, T. Eichler, J. Faria, S.H. Wilhelms, F. Kipfstuhl, S. Sheldon, S. Miller, H. Dahl-Jensen, D. Kleiner, T. |
author_sort |
Weikusat, I. |
title |
Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice |
title_short |
Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice |
title_full |
Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice |
title_fullStr |
Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice |
title_full_unstemmed |
Physical analysis of an Antarctic ice core-towards an integration of micro-and macrodynamics of polar ice |
title_sort |
physical analysis of an antarctic ice core-towards an integration of micro-and macrodynamics of polar ice |
publisher |
Royal Society |
publishDate |
2017 |
url |
http://hdl.handle.net/10810/44038 https://doi.org/10.1098/rsta.2015.0347 |
long_lat |
ENVELOPE(0.000,0.000,-75.000,-75.000) ENVELOPE(0.000,0.000,-75.000,-75.000) |
geographic |
Antarctic Dronning Maud Land Kohnen Kohnen Station |
geographic_facet |
Antarctic Dronning Maud Land Kohnen Kohnen Station |
genre |
Antarc* Antarctic Antarctica DML Dronning Maud Land ice core Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica DML Dronning Maud Land ice core Ice Sheet |
op_relation |
info:eu-repo/grantAgreement/MINECO/RYC-2012-12167 ES/1PE/RYC-2012-12167 https://dx.doi.org/10.1098/rsta.2015.0347 Philosophical Transactions Of The Royal Society A-Mathematical Physical And Engineering Sciences 375(2086) : 20150347 (2017) 1364-503X http://hdl.handle.net/10810/44038 doi:10.1098/rsta.2015.0347 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-sa/3.0/en/ (c) 2016 The Author(s) Published by the Royal Society. All rights reserved. |
op_rightsnorm |
CC-BY-NC-SA |
op_doi |
https://doi.org/10.1098/rsta.2015.0347 |
container_title |
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |
container_volume |
375 |
container_issue |
2086 |
container_start_page |
20150347 |
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1766048548763205632 |