A stratigraphy-based method for reconstructing ice core orientation
Abstract Ever since the first deep ice cores were drilled, it has been a challenge to determine their original, in-situ orientation. In general, the orientation of an ice core is lost as the drill is free to rotate during transport to the surface. For shallow ice cores, it is usually possible to mat...
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Online Access: | http://dx.doi.org/10.1017/aog.2020.76 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305520000762 |
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crcambridgeupr:10.1017/aog.2020.76 2024-06-09T07:38:33+00:00 A stratigraphy-based method for reconstructing ice core orientation Westhoff, Julien Stoll, Nicolas Franke, Steven Weikusat, Ilka Bons, Paul Kerch, Johanna Jansen, Daniela Kipfstuhl, Sepp Dahl-Jensen, Dorthe 2020 http://dx.doi.org/10.1017/aog.2020.76 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305520000762 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Annals of Glaciology volume 62, issue 85-86, page 191-202 ISSN 0260-3055 1727-5644 journal-article 2020 crcambridgeupr https://doi.org/10.1017/aog.2020.76 2024-05-15T13:08:45Z Abstract Ever since the first deep ice cores were drilled, it has been a challenge to determine their original, in-situ orientation. In general, the orientation of an ice core is lost as the drill is free to rotate during transport to the surface. For shallow ice cores, it is usually possible to match the adjacent core breaks, which preserves the orientation of the ice column. However, this method fails for deep ice cores, such as the EastGRIP ice core in Northeast Greenland. We provide a method to reconstruct ice core orientation using visual stratigraphy and borehole geometry. As the EastGRIP ice core is drilled through the Northeast Greenland Ice Stream, we use information about the directional structures to perform a full geographical re-orientation. We compared the core orientation with logging data from core break matching and the pattern of the stereographic projections of the crystals’ c -axis orientations. Both comparisons agree very well with the proposed orientation method. The method works well for 441 out of 451 samples from a depth of 1375–2120 m in the EastGRIP ice core. It can also be applied to other ice cores, providing a better foundation for interpreting physical properties and understanding the flow of ice. Article in Journal/Newspaper Annals of Glaciology Greenland ice core Cambridge University Press Greenland Annals of Glaciology 1 12 |
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Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
Abstract Ever since the first deep ice cores were drilled, it has been a challenge to determine their original, in-situ orientation. In general, the orientation of an ice core is lost as the drill is free to rotate during transport to the surface. For shallow ice cores, it is usually possible to match the adjacent core breaks, which preserves the orientation of the ice column. However, this method fails for deep ice cores, such as the EastGRIP ice core in Northeast Greenland. We provide a method to reconstruct ice core orientation using visual stratigraphy and borehole geometry. As the EastGRIP ice core is drilled through the Northeast Greenland Ice Stream, we use information about the directional structures to perform a full geographical re-orientation. We compared the core orientation with logging data from core break matching and the pattern of the stereographic projections of the crystals’ c -axis orientations. Both comparisons agree very well with the proposed orientation method. The method works well for 441 out of 451 samples from a depth of 1375–2120 m in the EastGRIP ice core. It can also be applied to other ice cores, providing a better foundation for interpreting physical properties and understanding the flow of ice. |
format |
Article in Journal/Newspaper |
author |
Westhoff, Julien Stoll, Nicolas Franke, Steven Weikusat, Ilka Bons, Paul Kerch, Johanna Jansen, Daniela Kipfstuhl, Sepp Dahl-Jensen, Dorthe |
spellingShingle |
Westhoff, Julien Stoll, Nicolas Franke, Steven Weikusat, Ilka Bons, Paul Kerch, Johanna Jansen, Daniela Kipfstuhl, Sepp Dahl-Jensen, Dorthe A stratigraphy-based method for reconstructing ice core orientation |
author_facet |
Westhoff, Julien Stoll, Nicolas Franke, Steven Weikusat, Ilka Bons, Paul Kerch, Johanna Jansen, Daniela Kipfstuhl, Sepp Dahl-Jensen, Dorthe |
author_sort |
Westhoff, Julien |
title |
A stratigraphy-based method for reconstructing ice core orientation |
title_short |
A stratigraphy-based method for reconstructing ice core orientation |
title_full |
A stratigraphy-based method for reconstructing ice core orientation |
title_fullStr |
A stratigraphy-based method for reconstructing ice core orientation |
title_full_unstemmed |
A stratigraphy-based method for reconstructing ice core orientation |
title_sort |
stratigraphy-based method for reconstructing ice core orientation |
publisher |
Cambridge University Press (CUP) |
publishDate |
2020 |
url |
http://dx.doi.org/10.1017/aog.2020.76 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305520000762 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Annals of Glaciology Greenland ice core |
genre_facet |
Annals of Glaciology Greenland ice core |
op_source |
Annals of Glaciology volume 62, issue 85-86, page 191-202 ISSN 0260-3055 1727-5644 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/aog.2020.76 |
container_title |
Annals of Glaciology |
container_start_page |
1 |
op_container_end_page |
12 |
_version_ |
1801373616922689536 |