Wet subglacial bedforms of the NE Greenland Ice Stream shear margins
Abstract We describe elongate, wet, subglacial bedforms in the shear margins of the NE Greenland Ice Stream and place some constraints on their formation. Lateral shear margin moraines have been observed across the previously glaciated landscape, but little is known about the ice-flow conditions nec...
Published in: | Annals of Glaciology |
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Online Access: | http://dx.doi.org/10.1017/aog.2019.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305519000430 |
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crcambridgeupr:10.1017/aog.2019.43 2024-06-23T07:45:35+00:00 Wet subglacial bedforms of the NE Greenland Ice Stream shear margins Riverman, Kiya L. Anandakrishnan, Sridhar Alley, Richard B. Holschuh, Nicholas Dow, Christine F. Muto, Atsuhiro Parizek, Byron R. Christianson, Knut Peters, Leo E. 2019 http://dx.doi.org/10.1017/aog.2019.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305519000430 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Annals of Glaciology volume 60, issue 80, page 91-99 ISSN 0260-3055 1727-5644 journal-article 2019 crcambridgeupr https://doi.org/10.1017/aog.2019.43 2024-06-05T04:04:31Z Abstract We describe elongate, wet, subglacial bedforms in the shear margins of the NE Greenland Ice Stream and place some constraints on their formation. Lateral shear margin moraines have been observed across the previously glaciated landscape, but little is known about the ice-flow conditions necessary to form these bedforms. Here we describe in situ sediment bedforms under the NE Greenland Ice Stream shear margins that are observed in active-source seismic and ground-penetrating radar surveys. We find bedforms in the shear margins that are ~500 m wide, ~50 m tall, and elongated nearly parallel to ice-flow, including what we believe to be the first subglacial observation of a shear margin moraine. Acoustic impedance analysis of the bedforms shows that they are composed of unconsolidated, deformable, water-saturated till. We use these geophysical observations to place constraints on the possible formation mechanism of these subglacial features. Article in Journal/Newspaper Annals of Glaciology Greenland Cambridge University Press Greenland Annals of Glaciology 60 80 91 99 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
Abstract We describe elongate, wet, subglacial bedforms in the shear margins of the NE Greenland Ice Stream and place some constraints on their formation. Lateral shear margin moraines have been observed across the previously glaciated landscape, but little is known about the ice-flow conditions necessary to form these bedforms. Here we describe in situ sediment bedforms under the NE Greenland Ice Stream shear margins that are observed in active-source seismic and ground-penetrating radar surveys. We find bedforms in the shear margins that are ~500 m wide, ~50 m tall, and elongated nearly parallel to ice-flow, including what we believe to be the first subglacial observation of a shear margin moraine. Acoustic impedance analysis of the bedforms shows that they are composed of unconsolidated, deformable, water-saturated till. We use these geophysical observations to place constraints on the possible formation mechanism of these subglacial features. |
format |
Article in Journal/Newspaper |
author |
Riverman, Kiya L. Anandakrishnan, Sridhar Alley, Richard B. Holschuh, Nicholas Dow, Christine F. Muto, Atsuhiro Parizek, Byron R. Christianson, Knut Peters, Leo E. |
spellingShingle |
Riverman, Kiya L. Anandakrishnan, Sridhar Alley, Richard B. Holschuh, Nicholas Dow, Christine F. Muto, Atsuhiro Parizek, Byron R. Christianson, Knut Peters, Leo E. Wet subglacial bedforms of the NE Greenland Ice Stream shear margins |
author_facet |
Riverman, Kiya L. Anandakrishnan, Sridhar Alley, Richard B. Holschuh, Nicholas Dow, Christine F. Muto, Atsuhiro Parizek, Byron R. Christianson, Knut Peters, Leo E. |
author_sort |
Riverman, Kiya L. |
title |
Wet subglacial bedforms of the NE Greenland Ice Stream shear margins |
title_short |
Wet subglacial bedforms of the NE Greenland Ice Stream shear margins |
title_full |
Wet subglacial bedforms of the NE Greenland Ice Stream shear margins |
title_fullStr |
Wet subglacial bedforms of the NE Greenland Ice Stream shear margins |
title_full_unstemmed |
Wet subglacial bedforms of the NE Greenland Ice Stream shear margins |
title_sort |
wet subglacial bedforms of the ne greenland ice stream shear margins |
publisher |
Cambridge University Press (CUP) |
publishDate |
2019 |
url |
http://dx.doi.org/10.1017/aog.2019.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305519000430 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Annals of Glaciology Greenland |
genre_facet |
Annals of Glaciology Greenland |
op_source |
Annals of Glaciology volume 60, issue 80, page 91-99 ISSN 0260-3055 1727-5644 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/aog.2019.43 |
container_title |
Annals of Glaciology |
container_volume |
60 |
container_issue |
80 |
container_start_page |
91 |
op_container_end_page |
99 |
_version_ |
1802641377179205632 |