Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution
Published version at http://doi.org/10.1016/j.quascirev.2016.07.012 . License CC BY-NC-ND 4.0 . 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 e...
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Online Access: | https://hdl.handle.net/10037/10521 https://doi.org/10.1016/j.quascirev.2016.07.012 |
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ftunivtroemsoe:oai:munin.uit.no:10037/10521 2023-05-15T13:58:43+02:00 Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution Patton, Henry Swift, D.A. Clark, C.D. Livingstone, Stephen J. Cook, S.J. 2016-09-15 https://hdl.handle.net/10037/10521 https://doi.org/10.1016/j.quascirev.2016.07.012 eng eng Elsevier Quaternary Science Reviews info:eu-repo/grantAgreement/RCN//200672/Norway/PetroMaks/GlaciBar/ info:eu-repo/grantAgreement/RCN//223259/Norway/// FRIDAID 1369102 doi:10.1016/j.quascirev.2016.07.012 0277-3791 1873-457X https://hdl.handle.net/10037/10521 openAccess Glacial erosion Landscape evolution Overdeepening Geomorphology Ice sheet VDP::Mathematics and natural science: 400::Geosciences: 450 Journal article Tidsskriftartikkel Peer reviewed 2016 ftunivtroemsoe https://doi.org/10.1016/j.quascirev.2016.07.012 2021-06-25T17:55:06Z Published version at http://doi.org/10.1016/j.quascirev.2016.07.012 . License CC BY-NC-ND 4.0 . 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 University of Tromsø: Munin Open Research Archive 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 |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
Glacial erosion Landscape evolution Overdeepening Geomorphology Ice sheet VDP::Mathematics and natural science: 400::Geosciences: 450 |
spellingShingle |
Glacial erosion Landscape evolution Overdeepening Geomorphology Ice sheet VDP::Mathematics and natural science: 400::Geosciences: 450 Patton, Henry Swift, D.A. Clark, C.D. Livingstone, Stephen J. Cook, S.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 VDP::Mathematics and natural science: 400::Geosciences: 450 |
description |
Published version at http://doi.org/10.1016/j.quascirev.2016.07.012 . License CC BY-NC-ND 4.0 . 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, Henry Swift, D.A. Clark, C.D. Livingstone, Stephen J. Cook, S.J. |
author_facet |
Patton, Henry Swift, D.A. Clark, C.D. Livingstone, Stephen J. Cook, S.J. |
author_sort |
Patton, Henry |
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 |
publisher |
Elsevier |
publishDate |
2016 |
url |
https://hdl.handle.net/10037/10521 https://doi.org/10.1016/j.quascirev.2016.07.012 |
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_relation |
Quaternary Science Reviews info:eu-repo/grantAgreement/RCN//200672/Norway/PetroMaks/GlaciBar/ info:eu-repo/grantAgreement/RCN//223259/Norway/// FRIDAID 1369102 doi:10.1016/j.quascirev.2016.07.012 0277-3791 1873-457X https://hdl.handle.net/10037/10521 |
op_rights |
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 |
_version_ |
1766267059820298240 |