Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet
It has been hypothesized that complex englacial structures identified within the East Antarctic and Greenland ice sheets are generated by (i) water freezing to the ice sheet base and evolving under ice flow, (ii) deformation of ice of varying rheology, or (iii) entrainment of basal material. Using i...
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ftcopernicus:oai:publications.copernicus.org:tc80921 2023-05-15T13:55:28+02:00 Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet Ross, Neil Corr, Hugh Siegert, Martin 2020-06-30 application/pdf https://doi.org/10.5194/tc-14-2103-2020 https://tc.copernicus.org/articles/14/2103/2020/ eng eng doi:10.5194/tc-14-2103-2020 https://tc.copernicus.org/articles/14/2103/2020/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-14-2103-2020 2020-07-20T16:22:03Z It has been hypothesized that complex englacial structures identified within the East Antarctic and Greenland ice sheets are generated by (i) water freezing to the ice sheet base and evolving under ice flow, (ii) deformation of ice of varying rheology, or (iii) entrainment of basal material. Using ice-penetrating radar, we identify a widespread complex of deep-ice facies in West Antarctica that exist in the absence of basal water. These deep-ice units are extensive, thick ( >500 m), and incorporate multiple highly reflective englacial layers. At the lateral margin of an enhanced flow tributary of the Institute Ice Stream, these units are heavily deformed and folded by the action of lateral flow convergence. Radar reflectivity analysis demonstrates that the uppermost reflector of the deep-ice package is highly anisotropic, due to abrupt alternations in crystal orientation fabric, and consequently will have a different rheology to the ice above and below it. Deformation and folding of the deep-ice package is an englacial response to the combination of laterally-convergent ice flow and the physical properties of the ice column. Text Antarc* Antarctic Antarctica Greenland Ice Sheet Institute Ice Stream West Antarctica Copernicus Publications: E-Journals Antarctic Greenland Institute Ice Stream ENVELOPE(-75.000,-75.000,-82.000,-82.000) West Antarctic Ice Sheet West Antarctica The Cryosphere 14 6 2103 2114 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
It has been hypothesized that complex englacial structures identified within the East Antarctic and Greenland ice sheets are generated by (i) water freezing to the ice sheet base and evolving under ice flow, (ii) deformation of ice of varying rheology, or (iii) entrainment of basal material. Using ice-penetrating radar, we identify a widespread complex of deep-ice facies in West Antarctica that exist in the absence of basal water. These deep-ice units are extensive, thick ( >500 m), and incorporate multiple highly reflective englacial layers. At the lateral margin of an enhanced flow tributary of the Institute Ice Stream, these units are heavily deformed and folded by the action of lateral flow convergence. Radar reflectivity analysis demonstrates that the uppermost reflector of the deep-ice package is highly anisotropic, due to abrupt alternations in crystal orientation fabric, and consequently will have a different rheology to the ice above and below it. Deformation and folding of the deep-ice package is an englacial response to the combination of laterally-convergent ice flow and the physical properties of the ice column. |
format |
Text |
author |
Ross, Neil Corr, Hugh Siegert, Martin |
spellingShingle |
Ross, Neil Corr, Hugh Siegert, Martin Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet |
author_facet |
Ross, Neil Corr, Hugh Siegert, Martin |
author_sort |
Ross, Neil |
title |
Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet |
title_short |
Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet |
title_full |
Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet |
title_fullStr |
Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet |
title_full_unstemmed |
Large-scale englacial folding and deep-ice stratigraphy within the West Antarctic Ice Sheet |
title_sort |
large-scale englacial folding and deep-ice stratigraphy within the west antarctic ice sheet |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-2103-2020 https://tc.copernicus.org/articles/14/2103/2020/ |
long_lat |
ENVELOPE(-75.000,-75.000,-82.000,-82.000) |
geographic |
Antarctic Greenland Institute Ice Stream West Antarctic Ice Sheet West Antarctica |
geographic_facet |
Antarctic Greenland Institute Ice Stream West Antarctic Ice Sheet West Antarctica |
genre |
Antarc* Antarctic Antarctica Greenland Ice Sheet Institute Ice Stream West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Greenland Ice Sheet Institute Ice Stream West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-14-2103-2020 https://tc.copernicus.org/articles/14/2103/2020/ |
op_doi |
https://doi.org/10.5194/tc-14-2103-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
6 |
container_start_page |
2103 |
op_container_end_page |
2114 |
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1766262085305499648 |