Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution
Abstract 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 dis...
Main Authors: | , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2016
|
Subjects: | |
Online Access: | https://e-space.mmu.ac.uk/616977/16/Patton_etal_QSR_2016.2-35.pdf |
id |
ftmanchuniv:oai:e-space.mmu.ac.uk:616977 |
---|---|
record_format |
openpolar |
spelling |
ftmanchuniv:oai:e-space.mmu.ac.uk:616977 2023-05-15T14:02:26+02:00 Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution Patton, H Swift, DA Clark, CD Livingstone, SJ Cook, SJ 2016-07-21 text https://e-space.mmu.ac.uk/616977/16/Patton_etal_QSR_2016.2-35.pdf en eng Elsevier https://e-space.mmu.ac.uk/616977/ http://www.sciencedirect.com/science/article/pii/S0277379116302463 10.1016/j.quascirev.2016.07.012 https://e-space.mmu.ac.uk/616977/16/Patton_etal_QSR_2016.2-35.pdf Patton, H </view/creators/Patton=3AH=3A=3A.html>, Swift, DA </view/creators/Swift=3ADA=3A=3A.html>, Clark, CD </view/creators/Clark=3ACD=3A=3A.html>, Livingstone, SJ </view/creators/Livingstone=3ASJ=3A=3A.html> and Cook, SJ </view/creators/Cook=3ASJ=3A=3A.html> (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 info:eu-repo/semantics/openAccess CC-BY-NC-ND Article PeerReviewed 2016 ftmanchuniv 2023-01-29T07:21:02Z Abstract 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 eSpace - Manchester Metropolitan University's Research Repository 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) |
institution |
Open Polar |
collection |
eSpace - Manchester Metropolitan University's Research Repository |
op_collection_id |
ftmanchuniv |
language |
English |
description |
Abstract 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, DA Clark, CD Livingstone, SJ Cook, SJ |
spellingShingle |
Patton, H Swift, DA Clark, CD Livingstone, SJ Cook, SJ Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution |
author_facet |
Patton, H Swift, DA Clark, CD Livingstone, SJ Cook, SJ |
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://e-space.mmu.ac.uk/616977/16/Patton_etal_QSR_2016.2-35.pdf |
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://e-space.mmu.ac.uk/616977/ http://www.sciencedirect.com/science/article/pii/S0277379116302463 10.1016/j.quascirev.2016.07.012 https://e-space.mmu.ac.uk/616977/16/Patton_etal_QSR_2016.2-35.pdf Patton, H </view/creators/Patton=3AH=3A=3A.html>, Swift, DA </view/creators/Swift=3ADA=3A=3A.html>, Clark, CD </view/creators/Clark=3ACD=3A=3A.html>, Livingstone, SJ </view/creators/Livingstone=3ASJ=3A=3A.html> and Cook, SJ </view/creators/Cook=3ASJ=3A=3A.html> (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 info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766272697336070144 |