How dynamic are ice-stream beds?
Projections of sea-level rise contributions from West Antarctica's dynamically thinning ice streams contain high uncertainty because some of the key processes involved are extremely challenging to observe. An especially poorly observed parameter is sub-decadal stability of ice-stream beds, whic...
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ftleedsuniv:oai:eprints.whiterose.ac.uk:128474 2023-05-15T13:52:14+02:00 How dynamic are ice-stream beds? Davies, D Bingham, RG King, EC Smith, AM Brisbourne, AM Spagnolo, M Graham, AGC Hogg, AE Vaughan, DG 2018-05-04 text https://eprints.whiterose.ac.uk/128474/ https://eprints.whiterose.ac.uk/128474/14/Davies%20et%20al%202018.pdf en eng European Geosciences Union https://eprints.whiterose.ac.uk/128474/14/Davies%20et%20al%202018.pdf Davies, D, Bingham, RG, King, EC et al. (6 more authors) (2018) How dynamic are ice-stream beds? The Cryosphere, 12 (5). pp. 1615-1628. ISSN 1994-0416 cc_by_4 CC-BY Article NonPeerReviewed 2018 ftleedsuniv 2023-01-30T22:04:41Z Projections of sea-level rise contributions from West Antarctica's dynamically thinning ice streams contain high uncertainty because some of the key processes involved are extremely challenging to observe. An especially poorly observed parameter is sub-decadal stability of ice-stream beds, which may be important for subglacial traction, till continuity and landform development. Only two previous studies have made repeated geophysical measurements of ice-stream beds at the same locations in different years, but both studies were limited in spatial extent. Here, we present the results from repeat radar measurements of the bed of Pine Island Glacier, West Antarctica, conducted 3–6 years apart, along a cumulative ∼ 60 km of profiles. Analysis of the correlation of bed picks between repeat surveys shows that 90 % of the bed displays no significant change despite the glacier increasing in speed by up to 40 % over the last decade. We attribute the negligible detection of morphological change at the bed of Pine Island Glacier to the ubiquitous presence of a deforming till layer, wherein sediment transport is in steady state, such that sediment is transported along the basal interface without inducing morphological change to the radar-sounded basal interface. Given the precision of our measurements, the upper limit of subglacial erosion observed here is 500 mm a‾¹, far exceeding erosion rates reported for glacial settings from proglacial sediment yields, but substantially below subglacial erosion rates of 1.0 m a‾¹ previously reported from repeat geophysical surveys in West Antarctica. Article in Journal/Newspaper Antarc* Antarctica Pine Island Pine Island Glacier The Cryosphere West Antarctica White Rose Research Online (Universities of Leeds, Sheffield & York) West Antarctica Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
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Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
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ftleedsuniv |
language |
English |
description |
Projections of sea-level rise contributions from West Antarctica's dynamically thinning ice streams contain high uncertainty because some of the key processes involved are extremely challenging to observe. An especially poorly observed parameter is sub-decadal stability of ice-stream beds, which may be important for subglacial traction, till continuity and landform development. Only two previous studies have made repeated geophysical measurements of ice-stream beds at the same locations in different years, but both studies were limited in spatial extent. Here, we present the results from repeat radar measurements of the bed of Pine Island Glacier, West Antarctica, conducted 3–6 years apart, along a cumulative ∼ 60 km of profiles. Analysis of the correlation of bed picks between repeat surveys shows that 90 % of the bed displays no significant change despite the glacier increasing in speed by up to 40 % over the last decade. We attribute the negligible detection of morphological change at the bed of Pine Island Glacier to the ubiquitous presence of a deforming till layer, wherein sediment transport is in steady state, such that sediment is transported along the basal interface without inducing morphological change to the radar-sounded basal interface. Given the precision of our measurements, the upper limit of subglacial erosion observed here is 500 mm a‾¹, far exceeding erosion rates reported for glacial settings from proglacial sediment yields, but substantially below subglacial erosion rates of 1.0 m a‾¹ previously reported from repeat geophysical surveys in West Antarctica. |
format |
Article in Journal/Newspaper |
author |
Davies, D Bingham, RG King, EC Smith, AM Brisbourne, AM Spagnolo, M Graham, AGC Hogg, AE Vaughan, DG |
spellingShingle |
Davies, D Bingham, RG King, EC Smith, AM Brisbourne, AM Spagnolo, M Graham, AGC Hogg, AE Vaughan, DG How dynamic are ice-stream beds? |
author_facet |
Davies, D Bingham, RG King, EC Smith, AM Brisbourne, AM Spagnolo, M Graham, AGC Hogg, AE Vaughan, DG |
author_sort |
Davies, D |
title |
How dynamic are ice-stream beds? |
title_short |
How dynamic are ice-stream beds? |
title_full |
How dynamic are ice-stream beds? |
title_fullStr |
How dynamic are ice-stream beds? |
title_full_unstemmed |
How dynamic are ice-stream beds? |
title_sort |
how dynamic are ice-stream beds? |
publisher |
European Geosciences Union |
publishDate |
2018 |
url |
https://eprints.whiterose.ac.uk/128474/ https://eprints.whiterose.ac.uk/128474/14/Davies%20et%20al%202018.pdf |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
geographic |
West Antarctica Pine Island Glacier |
geographic_facet |
West Antarctica Pine Island Glacier |
genre |
Antarc* Antarctica Pine Island Pine Island Glacier The Cryosphere West Antarctica |
genre_facet |
Antarc* Antarctica Pine Island Pine Island Glacier The Cryosphere West Antarctica |
op_relation |
https://eprints.whiterose.ac.uk/128474/14/Davies%20et%20al%202018.pdf Davies, D, Bingham, RG, King, EC et al. (6 more authors) (2018) How dynamic are ice-stream beds? The Cryosphere, 12 (5). pp. 1615-1628. ISSN 1994-0416 |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
_version_ |
1766256506491109376 |