GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic
The erosional impacts of former ice sheets on the low-relief bedrock surfaces of Northern Hemisphere shields are not well understood. This paper assesses the variable impacts of glacial erosion on a portion of Baffin Island, eastern Canadian Arctic, between 68° and 72°N and 66° and 80°W. This tilted...
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crcansciencepubl:10.1139/cjes-2015-0063 2024-06-23T07:50:18+00:00 GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic Ebert, Karin Brodaric, Boyan 2015 http://dx.doi.org/10.1139/cjes-2015-0063 http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjes-2015-0063 http://www.nrcresearchpress.com/doi/pdf/10.1139/cjes-2015-0063 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 52, issue 11, page 966-979 ISSN 0008-4077 1480-3313 journal-article 2015 crcansciencepubl https://doi.org/10.1139/cjes-2015-0063 2024-05-30T08:13:48Z The erosional impacts of former ice sheets on the low-relief bedrock surfaces of Northern Hemisphere shields are not well understood. This paper assesses the variable impacts of glacial erosion on a portion of Baffin Island, eastern Canadian Arctic, between 68° and 72°N and 66° and 80°W. This tilted shield block was covered repeatedly by the Laurentide Ice Sheet during the late Cenozoic. The impact of ice-sheet erosion is examined with GIS analyses using two geomorphic parameters: lake density and terrain ruggedness. The resulting patterns generally conform to published data from other remote sensing studies, geological observations, cosmogenic exposure ages, and the distribution of the chemical index of alteration for tills. Lake density and terrain ruggedness are thereby demonstrated to be useful quantitative indicators of variable ice-sheet erosional impacts across Baffin Island. Ice-sheet erosion was most effective in the lower western parts of the lowlands, in a west–east-oriented band at around 350–400 m a.s.l., and in fjord-onset zones in the uplifted eastern region. Above the 350–400 m a.s.l. band and between the fjord-onset zones, ice-sheet erosion was not sufficient to create extensive ice-roughened or streamlined bedrock surfaces. The exception — where lake density and terrain ruggedness indicate that ice-sheet erosion had a scouring effect all across the study area — was in an area from Foxe Basin to Home Bay with elevations <400 m a.s.l. These morphological contrasts link to former ice-sheet basal thermal regimes during the Pleistocene. The zone of low glacial erosion surrounding the cold-based Barnes Ice Cap probably represents the ice cap’s greater extent during successive Pleistocene cold stages. Inter-fjord plateaus with few ice-sheet bedforms remained cold-based throughout multiple Pleistocene glaciations. In contrast, zones of high lake density and high terrain ruggedness are a result of the repeated development of fast-flowing, erosive ice in warm-based zones beneath the Laurentide Ice ... Article in Journal/Newspaper Arctic Baffin Island Baffin Barnes Ice Cap Foxe Basin Home bay Ice cap Ice Sheet Canadian Science Publishing Arctic Baffin Island Barnes Ice Cap ENVELOPE(-73.498,-73.498,70.001,70.001) Foxe Basin ENVELOPE(-77.918,-77.918,65.931,65.931) High Lake ENVELOPE(-110.849,-110.849,67.386,67.386) Canadian Journal of Earth Sciences 52 11 966 979 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
The erosional impacts of former ice sheets on the low-relief bedrock surfaces of Northern Hemisphere shields are not well understood. This paper assesses the variable impacts of glacial erosion on a portion of Baffin Island, eastern Canadian Arctic, between 68° and 72°N and 66° and 80°W. This tilted shield block was covered repeatedly by the Laurentide Ice Sheet during the late Cenozoic. The impact of ice-sheet erosion is examined with GIS analyses using two geomorphic parameters: lake density and terrain ruggedness. The resulting patterns generally conform to published data from other remote sensing studies, geological observations, cosmogenic exposure ages, and the distribution of the chemical index of alteration for tills. Lake density and terrain ruggedness are thereby demonstrated to be useful quantitative indicators of variable ice-sheet erosional impacts across Baffin Island. Ice-sheet erosion was most effective in the lower western parts of the lowlands, in a west–east-oriented band at around 350–400 m a.s.l., and in fjord-onset zones in the uplifted eastern region. Above the 350–400 m a.s.l. band and between the fjord-onset zones, ice-sheet erosion was not sufficient to create extensive ice-roughened or streamlined bedrock surfaces. The exception — where lake density and terrain ruggedness indicate that ice-sheet erosion had a scouring effect all across the study area — was in an area from Foxe Basin to Home Bay with elevations <400 m a.s.l. These morphological contrasts link to former ice-sheet basal thermal regimes during the Pleistocene. The zone of low glacial erosion surrounding the cold-based Barnes Ice Cap probably represents the ice cap’s greater extent during successive Pleistocene cold stages. Inter-fjord plateaus with few ice-sheet bedforms remained cold-based throughout multiple Pleistocene glaciations. In contrast, zones of high lake density and high terrain ruggedness are a result of the repeated development of fast-flowing, erosive ice in warm-based zones beneath the Laurentide Ice ... |
author2 |
Brodaric, Boyan |
format |
Article in Journal/Newspaper |
author |
Ebert, Karin |
spellingShingle |
Ebert, Karin GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic |
author_facet |
Ebert, Karin |
author_sort |
Ebert, Karin |
title |
GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic |
title_short |
GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic |
title_full |
GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic |
title_fullStr |
GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic |
title_full_unstemmed |
GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic |
title_sort |
gis analyses of ice-sheet erosional impacts on the exposed shield of baffin island, eastern canadian arctic |
publisher |
Canadian Science Publishing |
publishDate |
2015 |
url |
http://dx.doi.org/10.1139/cjes-2015-0063 http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjes-2015-0063 http://www.nrcresearchpress.com/doi/pdf/10.1139/cjes-2015-0063 |
long_lat |
ENVELOPE(-73.498,-73.498,70.001,70.001) ENVELOPE(-77.918,-77.918,65.931,65.931) ENVELOPE(-110.849,-110.849,67.386,67.386) |
geographic |
Arctic Baffin Island Barnes Ice Cap Foxe Basin High Lake |
geographic_facet |
Arctic Baffin Island Barnes Ice Cap Foxe Basin High Lake |
genre |
Arctic Baffin Island Baffin Barnes Ice Cap Foxe Basin Home bay Ice cap Ice Sheet |
genre_facet |
Arctic Baffin Island Baffin Barnes Ice Cap Foxe Basin Home bay Ice cap Ice Sheet |
op_source |
Canadian Journal of Earth Sciences volume 52, issue 11, page 966-979 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/cjes-2015-0063 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
52 |
container_issue |
11 |
container_start_page |
966 |
op_container_end_page |
979 |
_version_ |
1802641177299648512 |