Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough
The presence of a grounded Greenland Ice Sheet on the northeastern part of the Greenland continental shelf during the Last Glacial Maximum is supported by new swath bathymetry and high-resolution seismic data, supplemented with multi-proxy analyses of sediment gravity cores from Store Koldewey Troug...
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ftcopernicus:oai:publications.copernicus.org:tc81774 2023-05-15T16:19:43+02:00 Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough Olsen, Ingrid Leirvik Rydningen, Tom Arne Forwick, Matthias Laberg, Jan Sverre Husum, Katrine 2020-12-04 application/pdf https://doi.org/10.5194/tc-14-4475-2020 https://tc.copernicus.org/articles/14/4475/2020/ eng eng doi:10.5194/tc-14-4475-2020 https://tc.copernicus.org/articles/14/4475/2020/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-14-4475-2020 2020-12-07T17:22:16Z The presence of a grounded Greenland Ice Sheet on the northeastern part of the Greenland continental shelf during the Last Glacial Maximum is supported by new swath bathymetry and high-resolution seismic data, supplemented with multi-proxy analyses of sediment gravity cores from Store Koldewey Trough. Subglacial till fills the trough, with an overlying drape of maximum 2.5 m thick glacier-proximal and glacier-distal sediment. The presence of mega-scale glacial lineations and a grounding zone wedge in the outer part of the trough, comprising subglacial till, provides evidence of the expansion of fast-flowing, grounded ice, probably originating from the area presently covered with the Storstrømmen ice stream and thereby previously flowing across Store Koldewey Island and Germania Land. Grounding zone wedges and recessional moraines provide evidence that multiple halts and/or readvances interrupted the deglaciation. The formation of the grounding zone wedges is estimated to be at least 130 years, while distances between the recessional moraines indicate that the grounding line locally retreated between 80 and 400 m yr −1 during the deglaciation, assuming that the moraines formed annually. The complex geomorphology in Store Koldewey Trough is attributed to the trough shallowing and narrowing towards the coast. At a late stage of the deglaciation, the ice stream flowed around the topography on Store Koldewey Island and Germania Land, terminating the sediment input from this sector of the Greenland Ice Sheet to Store Koldewey Trough. Text Germania land glacier Greenland Ice Sheet Koldewey island Store koldewey Copernicus Publications: E-Journals Germania Land ENVELOPE(-20.042,-20.042,77.129,77.129) Greenland Store Koldewey ENVELOPE(-18.820,-18.820,76.364,76.364) The Cryosphere 14 12 4475 4494 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
The presence of a grounded Greenland Ice Sheet on the northeastern part of the Greenland continental shelf during the Last Glacial Maximum is supported by new swath bathymetry and high-resolution seismic data, supplemented with multi-proxy analyses of sediment gravity cores from Store Koldewey Trough. Subglacial till fills the trough, with an overlying drape of maximum 2.5 m thick glacier-proximal and glacier-distal sediment. The presence of mega-scale glacial lineations and a grounding zone wedge in the outer part of the trough, comprising subglacial till, provides evidence of the expansion of fast-flowing, grounded ice, probably originating from the area presently covered with the Storstrømmen ice stream and thereby previously flowing across Store Koldewey Island and Germania Land. Grounding zone wedges and recessional moraines provide evidence that multiple halts and/or readvances interrupted the deglaciation. The formation of the grounding zone wedges is estimated to be at least 130 years, while distances between the recessional moraines indicate that the grounding line locally retreated between 80 and 400 m yr −1 during the deglaciation, assuming that the moraines formed annually. The complex geomorphology in Store Koldewey Trough is attributed to the trough shallowing and narrowing towards the coast. At a late stage of the deglaciation, the ice stream flowed around the topography on Store Koldewey Island and Germania Land, terminating the sediment input from this sector of the Greenland Ice Sheet to Store Koldewey Trough. |
format |
Text |
author |
Olsen, Ingrid Leirvik Rydningen, Tom Arne Forwick, Matthias Laberg, Jan Sverre Husum, Katrine |
spellingShingle |
Olsen, Ingrid Leirvik Rydningen, Tom Arne Forwick, Matthias Laberg, Jan Sverre Husum, Katrine Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough |
author_facet |
Olsen, Ingrid Leirvik Rydningen, Tom Arne Forwick, Matthias Laberg, Jan Sverre Husum, Katrine |
author_sort |
Olsen, Ingrid Leirvik |
title |
Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough |
title_short |
Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough |
title_full |
Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough |
title_fullStr |
Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough |
title_full_unstemmed |
Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough |
title_sort |
last glacial ice sheet dynamics offshore ne greenland – a case study from store koldewey trough |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-4475-2020 https://tc.copernicus.org/articles/14/4475/2020/ |
long_lat |
ENVELOPE(-20.042,-20.042,77.129,77.129) ENVELOPE(-18.820,-18.820,76.364,76.364) |
geographic |
Germania Land Greenland Store Koldewey |
geographic_facet |
Germania Land Greenland Store Koldewey |
genre |
Germania land glacier Greenland Ice Sheet Koldewey island Store koldewey |
genre_facet |
Germania land glacier Greenland Ice Sheet Koldewey island Store koldewey |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-14-4475-2020 https://tc.copernicus.org/articles/14/4475/2020/ |
op_doi |
https://doi.org/10.5194/tc-14-4475-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
12 |
container_start_page |
4475 |
op_container_end_page |
4494 |
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