Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels
Subglacial meltwater channels (N-channels) are attributed to erosion by meltwater in subglacial conduits. They exert a major control on meltwater accumulation at the base of ice sheets, serving as drainage pathways and modifying ice flow rates. The study of exposed relict subglacial channels offers...
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2018
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/252788 2023-11-12T04:10:19+01:00 Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels Grau Galofre, Anna Jellinek, Mark Osinski, Gordon, R. Zanetti, Michael Kukko, Antero National Land Survey of Finland Maanmittauslaitos 2018-10-23T15:22:13Z application/pdf http://hdl.handle.net/10138/252788 eng eng Copernicus Publications The Cryosphere 1994-0416 4 12 http://hdl.handle.net/10138/252788 A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä A1 Journal article (refereed), original research article 2018 ftunivhelsihelda 2023-10-18T23:01:38Z Subglacial meltwater channels (N-channels) are attributed to erosion by meltwater in subglacial conduits. They exert a major control on meltwater accumulation at the base of ice sheets, serving as drainage pathways and modifying ice flow rates. The study of exposed relict subglacial channels offers a unique opportunity to characterize the geomorphologic fingerprint of subglacial erosion as well as study the structure and characteristics of ice sheet drainage systems. In this study we present detailed field and remote sensing observations of exposed subglacial meltwater channels in excellent preservation state on Devon Island (Canadian Arctic Archipelago). We characterize channel cross section, longitudinal profiles, and network morphologies and establish the spatial extent and distinctive characteristics of subglacial drainage systems. We use field-based GPS measurements of subglacial channel longitudinal profiles, along with stereo imagery-derived digital surface models (DSMs), and novel kinematic portable lidar data to establish a detailed characterization of subglacial channels in our field study area, including their distinction from rivers and other meltwater drainage systems. Subglacial channels typically cluster in groups of ˜ 10 channels and are oriented perpendicular to active or former ice margins. Although their overall direction generally follows topographic gradients, channels can be oblique to topographic gradients and have undulating longitudinal profiles. We also observe that the width of first-order tributaries is 1 to 2 orders of magnitude larger than in Devon Island river systems and approximately constant. Furthermore, our findings are consistent with theoretical expectations drawn from analyses of flow driven by gradients in effective water pressure related to variations in ice thickness. Our field and remote sensing observations represent the first high-resolution study of the subglacial geomorphology of the high Arctic, and provide quantitative and qualitative descriptions of subglacial ... Article in Journal/Newspaper Arctic Archipelago Arctic Canadian Arctic Archipelago Devon Island Ice Sheet The Cryosphere HELDA – University of Helsinki Open Repository Arctic Canada Canadian Arctic Archipelago Devon Island ENVELOPE(-88.000,-88.000,75.252,75.252) |
institution |
Open Polar |
collection |
HELDA – University of Helsinki Open Repository |
op_collection_id |
ftunivhelsihelda |
language |
English |
description |
Subglacial meltwater channels (N-channels) are attributed to erosion by meltwater in subglacial conduits. They exert a major control on meltwater accumulation at the base of ice sheets, serving as drainage pathways and modifying ice flow rates. The study of exposed relict subglacial channels offers a unique opportunity to characterize the geomorphologic fingerprint of subglacial erosion as well as study the structure and characteristics of ice sheet drainage systems. In this study we present detailed field and remote sensing observations of exposed subglacial meltwater channels in excellent preservation state on Devon Island (Canadian Arctic Archipelago). We characterize channel cross section, longitudinal profiles, and network morphologies and establish the spatial extent and distinctive characteristics of subglacial drainage systems. We use field-based GPS measurements of subglacial channel longitudinal profiles, along with stereo imagery-derived digital surface models (DSMs), and novel kinematic portable lidar data to establish a detailed characterization of subglacial channels in our field study area, including their distinction from rivers and other meltwater drainage systems. Subglacial channels typically cluster in groups of ˜ 10 channels and are oriented perpendicular to active or former ice margins. Although their overall direction generally follows topographic gradients, channels can be oblique to topographic gradients and have undulating longitudinal profiles. We also observe that the width of first-order tributaries is 1 to 2 orders of magnitude larger than in Devon Island river systems and approximately constant. Furthermore, our findings are consistent with theoretical expectations drawn from analyses of flow driven by gradients in effective water pressure related to variations in ice thickness. Our field and remote sensing observations represent the first high-resolution study of the subglacial geomorphology of the high Arctic, and provide quantitative and qualitative descriptions of subglacial ... |
author2 |
National Land Survey of Finland Maanmittauslaitos |
format |
Article in Journal/Newspaper |
author |
Grau Galofre, Anna Jellinek, Mark Osinski, Gordon, R. Zanetti, Michael Kukko, Antero |
spellingShingle |
Grau Galofre, Anna Jellinek, Mark Osinski, Gordon, R. Zanetti, Michael Kukko, Antero Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels |
author_facet |
Grau Galofre, Anna Jellinek, Mark Osinski, Gordon, R. Zanetti, Michael Kukko, Antero |
author_sort |
Grau Galofre, Anna |
title |
Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels |
title_short |
Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels |
title_full |
Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels |
title_fullStr |
Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels |
title_full_unstemmed |
Subglacial drainage patterns of Devon Island, Canada: detailed comparison of rivers and subglacial meltwater channels |
title_sort |
subglacial drainage patterns of devon island, canada: detailed comparison of rivers and subglacial meltwater channels |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
http://hdl.handle.net/10138/252788 |
long_lat |
ENVELOPE(-88.000,-88.000,75.252,75.252) |
geographic |
Arctic Canada Canadian Arctic Archipelago Devon Island |
geographic_facet |
Arctic Canada Canadian Arctic Archipelago Devon Island |
genre |
Arctic Archipelago Arctic Canadian Arctic Archipelago Devon Island Ice Sheet The Cryosphere |
genre_facet |
Arctic Archipelago Arctic Canadian Arctic Archipelago Devon Island Ice Sheet The Cryosphere |
op_relation |
The Cryosphere 1994-0416 4 12 http://hdl.handle.net/10138/252788 |
_version_ |
1782329841094230016 |