The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet
Abstract The Camp Century, Greenland, ice core was recovered from a bore hole which extended 1 375 m from the surface of the Greenland ice sheet to the ice/sub-ice interface. The bottom 15.7 m of the core contain over 300 alternating bands of clear and debris-laden ice. The size of the included debr...
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Language: | English |
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Cambridge University Press (CUP)
1979
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Online Access: | http://dx.doi.org/10.1017/s002214300002983x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300002983X |
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crcambridgeupr:10.1017/s002214300002983x 2024-06-16T07:40:09+00:00 The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet Herron, Susan Hoar Langway, Chester C. 1979 http://dx.doi.org/10.1017/s002214300002983x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300002983X en eng Cambridge University Press (CUP) Journal of Glaciology volume 23, issue 89, page 193-207 ISSN 0022-1430 1727-5652 journal-article 1979 crcambridgeupr https://doi.org/10.1017/s002214300002983x 2024-05-22T12:56:29Z Abstract The Camp Century, Greenland, ice core was recovered from a bore hole which extended 1 375 m from the surface of the Greenland ice sheet to the ice/sub-ice interface. The bottom 15.7 m of the core contain over 300 alternating bands of clear and debris-laden ice. The size of the included debris ranges from particles less than 2 μm in diameter to particle aggregates which are a maximum of 3 cm in diameter: the average debris concentration is 0.24 º º by weight. The debris size, concentration, and composition indicate that the debris originates from the till-like material directly below the debris-laden ice. The total gas concentration averages 51 ml/kg ice compared to the average of 101 ml/kg ice for the top 1 340 m. The gas composition of debris-bearing ice has apparently been modified by the oxidation of methane as reflected by traces of methane, high CO 2 levels, and low O 2 levels with respect to atmospheric air. Argon, which is not affected by the oxidation, shows an enrichment in samples with lower gas concentrations. Both the low gas concentrations in the debris-laden zone and the argon enrichment may be explained by the downward diffusion of gases from bubbly glacier ice into an originally bubble-free zone of refrozen debris-laden ice. Ice texture and ice-fabric analyses reveal extremely fine-grained ice and highly preferred crystal orientation in the lowermost 10 m of the core, indicating a zone of high deformation. Article in Journal/Newspaper glacier Greenland Greenland ice core ice core Ice Sheet Journal of Glaciology Cambridge University Press Greenland Journal of Glaciology 23 89 193 207 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract The Camp Century, Greenland, ice core was recovered from a bore hole which extended 1 375 m from the surface of the Greenland ice sheet to the ice/sub-ice interface. The bottom 15.7 m of the core contain over 300 alternating bands of clear and debris-laden ice. The size of the included debris ranges from particles less than 2 μm in diameter to particle aggregates which are a maximum of 3 cm in diameter: the average debris concentration is 0.24 º º by weight. The debris size, concentration, and composition indicate that the debris originates from the till-like material directly below the debris-laden ice. The total gas concentration averages 51 ml/kg ice compared to the average of 101 ml/kg ice for the top 1 340 m. The gas composition of debris-bearing ice has apparently been modified by the oxidation of methane as reflected by traces of methane, high CO 2 levels, and low O 2 levels with respect to atmospheric air. Argon, which is not affected by the oxidation, shows an enrichment in samples with lower gas concentrations. Both the low gas concentrations in the debris-laden zone and the argon enrichment may be explained by the downward diffusion of gases from bubbly glacier ice into an originally bubble-free zone of refrozen debris-laden ice. Ice texture and ice-fabric analyses reveal extremely fine-grained ice and highly preferred crystal orientation in the lowermost 10 m of the core, indicating a zone of high deformation. |
format |
Article in Journal/Newspaper |
author |
Herron, Susan Hoar Langway, Chester C. |
spellingShingle |
Herron, Susan Hoar Langway, Chester C. The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet |
author_facet |
Herron, Susan Hoar Langway, Chester C. |
author_sort |
Herron, Susan |
title |
The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet |
title_short |
The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet |
title_full |
The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet |
title_fullStr |
The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet |
title_full_unstemmed |
The Debris-Laden Ice at the Bottom of the Greenland Ice Sheet |
title_sort |
debris-laden ice at the bottom of the greenland ice sheet |
publisher |
Cambridge University Press (CUP) |
publishDate |
1979 |
url |
http://dx.doi.org/10.1017/s002214300002983x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300002983X |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Greenland ice core ice core Ice Sheet Journal of Glaciology |
genre_facet |
glacier Greenland Greenland ice core ice core Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology volume 23, issue 89, page 193-207 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s002214300002983x |
container_title |
Journal of Glaciology |
container_volume |
23 |
container_issue |
89 |
container_start_page |
193 |
op_container_end_page |
207 |
_version_ |
1802007012794433536 |