Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland
Petermann Fjord is a deep (>1000 m) fjord that incises the coastline of north-west Greenland and was carved by an expanded Petermann Glacier, one of the six largest outlet glaciers draining the modern Greenland Ice Sheet (GrIS). Between 5 and 70 m of unconsolidated glacigenic material infills in...
Published in: | The Cryosphere |
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Copernicus Publications
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Online Access: | https://doi.org/10.5194/tc-14-261-2020 https://www.the-cryosphere.net/14/261/2020/tc-14-261-2020.pdf https://doaj.org/article/85bb96dbdd5345c0bd1ed2c286ddcbbe |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:85bb96dbdd5345c0bd1ed2c286ddcbbe 2023-05-15T13:55:02+02:00 Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland K. A. Hogan M. Jakobsson L. Mayer B. T. Reilly A. E. Jennings J. S. Stoner T. Nielsen K. J. Andresen E. Nørmark K. A. Heirman E. Kamla K. Jerram C. Stranne A. Mix 2020-01-01 https://doi.org/10.5194/tc-14-261-2020 https://www.the-cryosphere.net/14/261/2020/tc-14-261-2020.pdf https://doaj.org/article/85bb96dbdd5345c0bd1ed2c286ddcbbe en eng Copernicus Publications doi:10.5194/tc-14-261-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/261/2020/tc-14-261-2020.pdf https://doaj.org/article/85bb96dbdd5345c0bd1ed2c286ddcbbe undefined The Cryosphere, Vol 14, Pp 261-286 (2020) geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.5194/tc-14-261-2020 2023-01-22T17:53:22Z Petermann Fjord is a deep (>1000 m) fjord that incises the coastline of north-west Greenland and was carved by an expanded Petermann Glacier, one of the six largest outlet glaciers draining the modern Greenland Ice Sheet (GrIS). Between 5 and 70 m of unconsolidated glacigenic material infills in the fjord and adjacent Nares Strait, deposited as the Petermann and Nares Strait ice streams retreated through the area after the Last Glacial Maximum. We have investigated the deglacial deposits using seismic stratigraphic techniques and have correlated our results with high-resolution bathymetric data and core lithofacies. We identify six seismo-acoustic facies in more than 3500 line kilometres of sub-bottom and seismic-reflection profiles throughout the fjord, Hall Basin and Kennedy Channel. Seismo-acoustic facies relate to bedrock or till surfaces (Facies I), subglacial deposition (Facies II), deposition from meltwater plumes and icebergs in quiescent glacimarine conditions (Facies III, IV), deposition at grounded ice margins during stillstands in retreat (grounding-zone wedges; Facies V) and the redeposition of material downslope (Facies IV). These sediment units represent the total volume of glacial sediment delivered to the mapped marine environment during retreat. We calculate a glacial sediment flux for the former Petermann ice stream as 1080–1420 m3 a−1 per metre of ice stream width and an average deglacial erosion rate for the basin of 0.29–0.34 mm a−1. Our deglacial erosion rates are consistent with results from Antarctic Peninsula fjord systems but are several times lower than values for other modern GrIS catchments. This difference is attributed to fact that large volumes of surface water do not access the bed in the Petermann system, and we conclude that glacial erosion is limited to areas overridden by streaming ice in this large outlet glacier setting. Erosion rates are also presented for two phases of ice retreat and confirm that there is significant variation in rates over a glacial–deglacial ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula glacier Greenland Hall Basin Ice Sheet Iceberg* Kennedy channel Nares strait Petermann Fjord Petermann glacier The Cryosphere Unknown Antarctic Antarctic Peninsula Greenland Nares ENVELOPE(158.167,158.167,-81.450,-81.450) Kennedy Channel ENVELOPE(-66.139,-66.139,80.919,80.919) Petermann Fjord ENVELOPE(-61.500,-61.500,81.167,81.167) Hall Basin ENVELOPE(-62.992,-62.992,81.502,81.502) The Cryosphere 14 1 261 286 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
geo |
spellingShingle |
geo K. A. Hogan M. Jakobsson L. Mayer B. T. Reilly A. E. Jennings J. S. Stoner T. Nielsen K. J. Andresen E. Nørmark K. A. Heirman E. Kamla K. Jerram C. Stranne A. Mix Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland |
topic_facet |
geo |
description |
Petermann Fjord is a deep (>1000 m) fjord that incises the coastline of north-west Greenland and was carved by an expanded Petermann Glacier, one of the six largest outlet glaciers draining the modern Greenland Ice Sheet (GrIS). Between 5 and 70 m of unconsolidated glacigenic material infills in the fjord and adjacent Nares Strait, deposited as the Petermann and Nares Strait ice streams retreated through the area after the Last Glacial Maximum. We have investigated the deglacial deposits using seismic stratigraphic techniques and have correlated our results with high-resolution bathymetric data and core lithofacies. We identify six seismo-acoustic facies in more than 3500 line kilometres of sub-bottom and seismic-reflection profiles throughout the fjord, Hall Basin and Kennedy Channel. Seismo-acoustic facies relate to bedrock or till surfaces (Facies I), subglacial deposition (Facies II), deposition from meltwater plumes and icebergs in quiescent glacimarine conditions (Facies III, IV), deposition at grounded ice margins during stillstands in retreat (grounding-zone wedges; Facies V) and the redeposition of material downslope (Facies IV). These sediment units represent the total volume of glacial sediment delivered to the mapped marine environment during retreat. We calculate a glacial sediment flux for the former Petermann ice stream as 1080–1420 m3 a−1 per metre of ice stream width and an average deglacial erosion rate for the basin of 0.29–0.34 mm a−1. Our deglacial erosion rates are consistent with results from Antarctic Peninsula fjord systems but are several times lower than values for other modern GrIS catchments. This difference is attributed to fact that large volumes of surface water do not access the bed in the Petermann system, and we conclude that glacial erosion is limited to areas overridden by streaming ice in this large outlet glacier setting. Erosion rates are also presented for two phases of ice retreat and confirm that there is significant variation in rates over a glacial–deglacial ... |
format |
Article in Journal/Newspaper |
author |
K. A. Hogan M. Jakobsson L. Mayer B. T. Reilly A. E. Jennings J. S. Stoner T. Nielsen K. J. Andresen E. Nørmark K. A. Heirman E. Kamla K. Jerram C. Stranne A. Mix |
author_facet |
K. A. Hogan M. Jakobsson L. Mayer B. T. Reilly A. E. Jennings J. S. Stoner T. Nielsen K. J. Andresen E. Nørmark K. A. Heirman E. Kamla K. Jerram C. Stranne A. Mix |
author_sort |
K. A. Hogan |
title |
Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland |
title_short |
Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland |
title_full |
Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland |
title_fullStr |
Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland |
title_full_unstemmed |
Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland |
title_sort |
glacial sedimentation, fluxes and erosion rates associated with ice retreat in petermann fjord and nares strait, north-west greenland |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-261-2020 https://www.the-cryosphere.net/14/261/2020/tc-14-261-2020.pdf https://doaj.org/article/85bb96dbdd5345c0bd1ed2c286ddcbbe |
long_lat |
ENVELOPE(158.167,158.167,-81.450,-81.450) ENVELOPE(-66.139,-66.139,80.919,80.919) ENVELOPE(-61.500,-61.500,81.167,81.167) ENVELOPE(-62.992,-62.992,81.502,81.502) |
geographic |
Antarctic Antarctic Peninsula Greenland Nares Kennedy Channel Petermann Fjord Hall Basin |
geographic_facet |
Antarctic Antarctic Peninsula Greenland Nares Kennedy Channel Petermann Fjord Hall Basin |
genre |
Antarc* Antarctic Antarctic Peninsula glacier Greenland Hall Basin Ice Sheet Iceberg* Kennedy channel Nares strait Petermann Fjord Petermann glacier The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctic Peninsula glacier Greenland Hall Basin Ice Sheet Iceberg* Kennedy channel Nares strait Petermann Fjord Petermann glacier The Cryosphere |
op_source |
The Cryosphere, Vol 14, Pp 261-286 (2020) |
op_relation |
doi:10.5194/tc-14-261-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/261/2020/tc-14-261-2020.pdf https://doaj.org/article/85bb96dbdd5345c0bd1ed2c286ddcbbe |
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undefined |
op_doi |
https://doi.org/10.5194/tc-14-261-2020 |
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The Cryosphere |
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14 |
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