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 location and...
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Online Access: | https://eprints.whiterose.ac.uk/102344/ https://eprints.whiterose.ac.uk/102344/24/Manuscript.pdf https://eprints.whiterose.ac.uk/102344/7/SupplementaryMaterial.pdf https://eprints.whiterose.ac.uk/102344/16/Figure04large.jpg https://doi.org/10.1016/j.quascirev.2016.07.012 |
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ftleedsuniv:oai:eprints.whiterose.ac.uk:102344 2023-05-15T13:49:59+02:00 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, S.J. 2016-09-15 text image https://eprints.whiterose.ac.uk/102344/ https://eprints.whiterose.ac.uk/102344/24/Manuscript.pdf https://eprints.whiterose.ac.uk/102344/7/SupplementaryMaterial.pdf https://eprints.whiterose.ac.uk/102344/16/Figure04large.jpg https://doi.org/10.1016/j.quascirev.2016.07.012 en eng Elsevier https://eprints.whiterose.ac.uk/102344/24/Manuscript.pdf https://eprints.whiterose.ac.uk/102344/7/SupplementaryMaterial.pdf https://eprints.whiterose.ac.uk/102344/16/Figure04large.jpg Patton, H., Swift, D.A. orcid.org/0000-0001-5320-5104 , Clark, C.D. et al. (2 more authors) (2016) Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution. Quaternary Science Reviews, 148. pp. 128-145. ISSN 0277-3791 cc_by_nc_nd_4 CC-BY-NC-ND Article PeerReviewed 2016 ftleedsuniv https://doi.org/10.1016/j.quascirev.2016.07.012 2023-01-30T21:44:21Z 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 location 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 to 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 White Rose Research Online (Universities of Leeds, Sheffield & York) Antarctic The Antarctic Greenland Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) Quaternary Science Reviews 148 128 145 |
institution |
Open Polar |
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White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
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 location 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 to 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, S.J. |
spellingShingle |
Patton, H. Swift, D.A. Clark, C.D. Livingstone, S.J. Cook, S.J. Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution |
author_facet |
Patton, H. Swift, D.A. Clark, C.D. Livingstone, S.J. Cook, S.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 |
publisher |
Elsevier |
publishDate |
2016 |
url |
https://eprints.whiterose.ac.uk/102344/ https://eprints.whiterose.ac.uk/102344/24/Manuscript.pdf https://eprints.whiterose.ac.uk/102344/7/SupplementaryMaterial.pdf https://eprints.whiterose.ac.uk/102344/16/Figure04large.jpg 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 The Antarctic Greenland Siple Siple Coast |
geographic_facet |
Antarctic The Antarctic Greenland Siple Siple Coast |
genre |
Antarc* Antarctic glacier Greenland Ice Sheet |
genre_facet |
Antarc* Antarctic glacier Greenland Ice Sheet |
op_relation |
https://eprints.whiterose.ac.uk/102344/24/Manuscript.pdf https://eprints.whiterose.ac.uk/102344/7/SupplementaryMaterial.pdf https://eprints.whiterose.ac.uk/102344/16/Figure04large.jpg Patton, H., Swift, D.A. orcid.org/0000-0001-5320-5104 , Clark, C.D. et al. (2 more authors) (2016) Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution. Quaternary Science Reviews, 148. pp. 128-145. ISSN 0277-3791 |
op_rights |
cc_by_nc_nd_4 |
op_rightsnorm |
CC-BY-NC-ND |
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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1766252673895497728 |