Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution
Glacier bed overdeepenings are ubiquitous in glacier systems and likely exert significant influence on ice dynamics, subglacial hydrology, and ice stability. Understanding of overdeepening formation and evolution has been hampered by an absence of quantitative empirical studies of their distribution...
Published in: | Quaternary Science Reviews |
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Online Access: | https://discovery.dundee.ac.uk/en/publications/e280d179-1b64-41c3-a6a6-01210f823d2f https://doi.org/10.1016/j.quascirev.2016.07.012 https://discovery.dundee.ac.uk/ws/files/20061864/1_s2.0_S0277379116302463_main.pdf |
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ftunivdundeepure:oai:discovery.dundee.ac.uk:publications/e280d179-1b64-41c3-a6a6-01210f823d2f 2024-06-23T07:47:08+00:00 Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution Patton, H. Swift, D. A. Clark, C. D. Livingstone, S. J. Cook, Simon J. 2016-09-15 application/pdf https://discovery.dundee.ac.uk/en/publications/e280d179-1b64-41c3-a6a6-01210f823d2f https://doi.org/10.1016/j.quascirev.2016.07.012 https://discovery.dundee.ac.uk/ws/files/20061864/1_s2.0_S0277379116302463_main.pdf eng eng https://discovery.dundee.ac.uk/en/publications/e280d179-1b64-41c3-a6a6-01210f823d2f info:eu-repo/semantics/openAccess Patton , H , Swift , D A , Clark , C D , Livingstone , S J & Cook , S J 2016 , ' Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets : Implications for overdeepening origin and evolution ' , Quaternary Science Reviews , vol. 148 , pp. 128-145 . https://doi.org/10.1016/j.quascirev.2016.07.012 Glacial erosion Landscape evolution Overdeepening Geomorphology Ice sheet /dk/atira/pure/subjectarea/asjc/2300/2306 name=Global and Planetary Change /dk/atira/pure/subjectarea/asjc/1200/1204 name=Archaeology /dk/atira/pure/subjectarea/asjc/1100/1105 name=Ecology Evolution Behavior and Systematics /dk/atira/pure/subjectarea/asjc/3300/3302 /dk/atira/pure/subjectarea/asjc/1900/1907 name=Geology article 2016 ftunivdundeepure https://doi.org/10.1016/j.quascirev.2016.07.012 2024-06-04T15:11:18Z Glacier bed overdeepenings are ubiquitous in glacier systems and likely exert significant influence on ice dynamics, subglacial hydrology, and ice stability. Understanding of overdeepening formation and evolution has been hampered by an absence of quantitative empirical studies of their distribution and morphology, with process insights having been drawn largely from theoretical or numerical studies. To address this shortcoming, we first map the distribution of potential overdeepenings beneath the Antarctic and Greenland ice sheets using a GIS-based algorithm that identifies closed-contours in the bed topography and then describe and analyse the characteristics and metrics of a subset of overdeepenings that pass further quality control criteria. Overdeepenings are found to be widespread, but are particularly associated with areas of topographically laterally constrained ice flow, notably near the ice sheet margins where outlet systems follow deeply incised troughs. Overdeepenings also occur in regions of topographically unconstrained ice flow (for example, beneath the Siple Coast ice streams and on the Greenland continental shelf). Metrics indicate that overdeepening growth is generally allometric and that topographic confinement of ice flow in general enhances overdeepening depth. However, overdeepening depth is skewed towards shallow values – typically 200–300 m – indicating that the rate of deepening slows with overdeepening age. This is reflected in a decline in adverse slope steepness with increasing overdeepening planform size. Finally, overdeepening long-profiles are found to support headward quarrying as the primary factor in overdeepening development. These observations support proposed negative feedbacks related to hydrology and sediment transport that stabilise overdeepening growth through sedimentation on the adverse slope but permit continued overdeepening planform enlargement by processes of headward erosion. Article in Journal/Newspaper Antarc* Antarctic glacier Greenland Ice Sheet Discovery - University of Dundee Online Publications Antarctic Greenland Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) The Antarctic Quaternary Science Reviews 148 128 145 |
institution |
Open Polar |
collection |
Discovery - University of Dundee Online Publications |
op_collection_id |
ftunivdundeepure |
language |
English |
topic |
Glacial erosion Landscape evolution Overdeepening Geomorphology Ice sheet /dk/atira/pure/subjectarea/asjc/2300/2306 name=Global and Planetary Change /dk/atira/pure/subjectarea/asjc/1200/1204 name=Archaeology /dk/atira/pure/subjectarea/asjc/1100/1105 name=Ecology Evolution Behavior and Systematics /dk/atira/pure/subjectarea/asjc/3300/3302 /dk/atira/pure/subjectarea/asjc/1900/1907 name=Geology |
spellingShingle |
Glacial erosion Landscape evolution Overdeepening Geomorphology Ice sheet /dk/atira/pure/subjectarea/asjc/2300/2306 name=Global and Planetary Change /dk/atira/pure/subjectarea/asjc/1200/1204 name=Archaeology /dk/atira/pure/subjectarea/asjc/1100/1105 name=Ecology Evolution Behavior and Systematics /dk/atira/pure/subjectarea/asjc/3300/3302 /dk/atira/pure/subjectarea/asjc/1900/1907 name=Geology Patton, H. Swift, D. A. Clark, C. D. Livingstone, S. J. Cook, Simon J. Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution |
topic_facet |
Glacial erosion Landscape evolution Overdeepening Geomorphology Ice sheet /dk/atira/pure/subjectarea/asjc/2300/2306 name=Global and Planetary Change /dk/atira/pure/subjectarea/asjc/1200/1204 name=Archaeology /dk/atira/pure/subjectarea/asjc/1100/1105 name=Ecology Evolution Behavior and Systematics /dk/atira/pure/subjectarea/asjc/3300/3302 /dk/atira/pure/subjectarea/asjc/1900/1907 name=Geology |
description |
Glacier bed overdeepenings are ubiquitous in glacier systems and likely exert significant influence on ice dynamics, subglacial hydrology, and ice stability. Understanding of overdeepening formation and evolution has been hampered by an absence of quantitative empirical studies of their distribution and morphology, with process insights having been drawn largely from theoretical or numerical studies. To address this shortcoming, we first map the distribution of potential overdeepenings beneath the Antarctic and Greenland ice sheets using a GIS-based algorithm that identifies closed-contours in the bed topography and then describe and analyse the characteristics and metrics of a subset of overdeepenings that pass further quality control criteria. Overdeepenings are found to be widespread, but are particularly associated with areas of topographically laterally constrained ice flow, notably near the ice sheet margins where outlet systems follow deeply incised troughs. Overdeepenings also occur in regions of topographically unconstrained ice flow (for example, beneath the Siple Coast ice streams and on the Greenland continental shelf). Metrics indicate that overdeepening growth is generally allometric and that topographic confinement of ice flow in general enhances overdeepening depth. However, overdeepening depth is skewed towards shallow values – typically 200–300 m – indicating that the rate of deepening slows with overdeepening age. This is reflected in a decline in adverse slope steepness with increasing overdeepening planform size. Finally, overdeepening long-profiles are found to support headward quarrying as the primary factor in overdeepening development. These observations support proposed negative feedbacks related to hydrology and sediment transport that stabilise overdeepening growth through sedimentation on the adverse slope but permit continued overdeepening planform enlargement by processes of headward erosion. |
format |
Article in Journal/Newspaper |
author |
Patton, H. Swift, D. A. Clark, C. D. Livingstone, S. J. Cook, Simon J. |
author_facet |
Patton, H. Swift, D. A. Clark, C. D. Livingstone, S. J. Cook, Simon J. |
author_sort |
Patton, H. |
title |
Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution |
title_short |
Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution |
title_full |
Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution |
title_fullStr |
Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution |
title_full_unstemmed |
Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets:Implications for overdeepening origin and evolution |
title_sort |
distribution and characteristics of overdeepenings beneath the greenland and antarctic ice sheets:implications for overdeepening origin and evolution |
publishDate |
2016 |
url |
https://discovery.dundee.ac.uk/en/publications/e280d179-1b64-41c3-a6a6-01210f823d2f https://doi.org/10.1016/j.quascirev.2016.07.012 https://discovery.dundee.ac.uk/ws/files/20061864/1_s2.0_S0277379116302463_main.pdf |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
geographic |
Antarctic Greenland Siple Siple Coast The Antarctic |
geographic_facet |
Antarctic Greenland Siple Siple Coast The Antarctic |
genre |
Antarc* Antarctic glacier Greenland Ice Sheet |
genre_facet |
Antarc* Antarctic glacier Greenland Ice Sheet |
op_source |
Patton , H , Swift , D A , Clark , C D , Livingstone , S J & Cook , S J 2016 , ' Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets : Implications for overdeepening origin and evolution ' , Quaternary Science Reviews , vol. 148 , pp. 128-145 . https://doi.org/10.1016/j.quascirev.2016.07.012 |
op_relation |
https://discovery.dundee.ac.uk/en/publications/e280d179-1b64-41c3-a6a6-01210f823d2f |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.quascirev.2016.07.012 |
container_title |
Quaternary Science Reviews |
container_volume |
148 |
container_start_page |
128 |
op_container_end_page |
145 |
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1802651228778266624 |