Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation?
A thin section study of crystal structure has been carried out on a 345 m long ice core drilled to bedrock on Hans Tausen Iskappe, 1995. In addition a meltlayer stratigraphy was set up, showing how the fraction of meltlayer-ice in the core increases with depth. Main characteristics of crystal struct...
Published in: | Meddelelser om Grønland. Geoscience |
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Format: | Article in Journal/Newspaper |
Language: | English |
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The Commission for Scientific Research in Greenland /Danish Polar Center
2001
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Online Access: | https://tidsskrift.dk/meddrgroenland_geosci/article/view/140229 |
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ftkbcopenhojs:oai:ojs.tidsskrift.dk:article/140229 2024-01-28T10:06:11+01:00 Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation? Nørgaard Madsen, Karen Thorsteinsson, Thorsteinn 2001-01-01 application/pdf https://tidsskrift.dk/meddrgroenland_geosci/article/view/140229 eng eng The Commission for Scientific Research in Greenland /Danish Polar Center https://tidsskrift.dk/meddrgroenland_geosci/article/view/140229/184222 https://tidsskrift.dk/meddrgroenland_geosci/article/view/140229 Meddelelser om Grønland. Geoscience; Vol. 39 (2001): Meddelelser om Grønland. Geoscience; 97-114 Meddelelser om Grønland. Geoscience; Årg. 39 (2001): Meddelelser om Grønland, Geoscience; 97-114 1600-4590 0106-1046 10.7146/moggeosci.v39i info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2001 ftkbcopenhojs https://doi.org/10.7146/moggeosci.v39i 2024-01-03T23:58:29Z A thin section study of crystal structure has been carried out on a 345 m long ice core drilled to bedrock on Hans Tausen Iskappe, 1995. In addition a meltlayer stratigraphy was set up, showing how the fraction of meltlayer-ice in the core increases with depth. Main characteristics of crystal structure are increasing mean crystal size from top to bottom in the core and development of a weak single maximum c-axis fabric. The rate of ice crystal growth in the well dated upper half of the core is much lower than expected from studies of the normal grain growth regime in other polar ice cores. Probably the grain boundary movements are impeded by impurities, which are present in relatively high concentrations in the Hans Tausen ice. Asuming the applicability of the calculated growth rate throughout the core, a late Holocene origin of the oldest ice is suggested by the size of the crystals close to bedrock. Presented data furthermore implies that bottom ice temperatures were never near the melting point and it is concluded that there was no ice cap on the Hans Tausen plateau earlier in Holocene. Article in Journal/Newspaper Greenland Hans Tausen iskappe Ice cap ice core North Greenland Tidsskrift.dk (The Royal Library, Denmark) Greenland Hans Tausen Iskappe ENVELOPE(-37.500,-37.500,82.583,82.583) Meddelelser om Grønland. Geoscience 39 |
institution |
Open Polar |
collection |
Tidsskrift.dk (The Royal Library, Denmark) |
op_collection_id |
ftkbcopenhojs |
language |
English |
description |
A thin section study of crystal structure has been carried out on a 345 m long ice core drilled to bedrock on Hans Tausen Iskappe, 1995. In addition a meltlayer stratigraphy was set up, showing how the fraction of meltlayer-ice in the core increases with depth. Main characteristics of crystal structure are increasing mean crystal size from top to bottom in the core and development of a weak single maximum c-axis fabric. The rate of ice crystal growth in the well dated upper half of the core is much lower than expected from studies of the normal grain growth regime in other polar ice cores. Probably the grain boundary movements are impeded by impurities, which are present in relatively high concentrations in the Hans Tausen ice. Asuming the applicability of the calculated growth rate throughout the core, a late Holocene origin of the oldest ice is suggested by the size of the crystals close to bedrock. Presented data furthermore implies that bottom ice temperatures were never near the melting point and it is concluded that there was no ice cap on the Hans Tausen plateau earlier in Holocene. |
format |
Article in Journal/Newspaper |
author |
Nørgaard Madsen, Karen Thorsteinsson, Thorsteinn |
spellingShingle |
Nørgaard Madsen, Karen Thorsteinsson, Thorsteinn Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation? |
author_facet |
Nørgaard Madsen, Karen Thorsteinsson, Thorsteinn |
author_sort |
Nørgaard Madsen, Karen |
title |
Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation? |
title_short |
Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation? |
title_full |
Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation? |
title_fullStr |
Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation? |
title_full_unstemmed |
Textures, fabrics and meltlayer stratigraphy in the Hans Tausen ice core, North Greenland - indications of late Holocene ice cap generation? |
title_sort |
textures, fabrics and meltlayer stratigraphy in the hans tausen ice core, north greenland - indications of late holocene ice cap generation? |
publisher |
The Commission for Scientific Research in Greenland /Danish Polar Center |
publishDate |
2001 |
url |
https://tidsskrift.dk/meddrgroenland_geosci/article/view/140229 |
long_lat |
ENVELOPE(-37.500,-37.500,82.583,82.583) |
geographic |
Greenland Hans Tausen Iskappe |
geographic_facet |
Greenland Hans Tausen Iskappe |
genre |
Greenland Hans Tausen iskappe Ice cap ice core North Greenland |
genre_facet |
Greenland Hans Tausen iskappe Ice cap ice core North Greenland |
op_source |
Meddelelser om Grønland. Geoscience; Vol. 39 (2001): Meddelelser om Grønland. Geoscience; 97-114 Meddelelser om Grønland. Geoscience; Årg. 39 (2001): Meddelelser om Grønland, Geoscience; 97-114 1600-4590 0106-1046 10.7146/moggeosci.v39i |
op_relation |
https://tidsskrift.dk/meddrgroenland_geosci/article/view/140229/184222 https://tidsskrift.dk/meddrgroenland_geosci/article/view/140229 |
op_doi |
https://doi.org/10.7146/moggeosci.v39i |
container_title |
Meddelelser om Grønland. Geoscience |
container_volume |
39 |
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1789332902682558464 |