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...
Published in: | The Cryosphere |
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Copernicus Publications
2018
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fttriple:oai:gotriple.eu:oai:doaj.org/article:ed22f11b2f9b4dc2b9ce2e89bc91b2ff 2023-05-15T13:38:15+02:00 How dynamic are ice-stream beds? D. Davies R. G. Bingham E. C. King A. M. Smith A. M. Brisbourne M. Spagnolo A. G. C. Graham A. E. Hogg D. G. Vaughan 2018-05-01 https://doi.org/10.5194/tc-12-1615-2018 https://www.the-cryosphere.net/12/1615/2018/tc-12-1615-2018.pdf https://doaj.org/article/ed22f11b2f9b4dc2b9ce2e89bc91b2ff en eng Copernicus Publications doi:10.5194/tc-12-1615-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/1615/2018/tc-12-1615-2018.pdf https://doaj.org/article/ed22f11b2f9b4dc2b9ce2e89bc91b2ff undefined The Cryosphere, Vol 12, Pp 1615-1628 (2018) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/tc-12-1615-2018 2023-01-22T18:14:10Z 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 Unknown Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) West Antarctica The Cryosphere 12 5 1615 1628 |
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Open Polar |
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fttriple |
language |
English |
topic |
geo envir |
spellingShingle |
geo envir D. Davies R. G. Bingham E. C. King A. M. Smith A. M. Brisbourne M. Spagnolo A. G. C. Graham A. E. Hogg D. G. Vaughan How dynamic are ice-stream beds? |
topic_facet |
geo envir |
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 |
D. Davies R. G. Bingham E. C. King A. M. Smith A. M. Brisbourne M. Spagnolo A. G. C. Graham A. E. Hogg D. G. Vaughan |
author_facet |
D. Davies R. G. Bingham E. C. King A. M. Smith A. M. Brisbourne M. Spagnolo A. G. C. Graham A. E. Hogg D. G. Vaughan |
author_sort |
D. Davies |
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 |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-1615-2018 https://www.the-cryosphere.net/12/1615/2018/tc-12-1615-2018.pdf https://doaj.org/article/ed22f11b2f9b4dc2b9ce2e89bc91b2ff |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
geographic |
Pine Island Glacier West Antarctica |
geographic_facet |
Pine Island Glacier West Antarctica |
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_source |
The Cryosphere, Vol 12, Pp 1615-1628 (2018) |
op_relation |
doi:10.5194/tc-12-1615-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/1615/2018/tc-12-1615-2018.pdf https://doaj.org/article/ed22f11b2f9b4dc2b9ce2e89bc91b2ff |
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undefined |
op_doi |
https://doi.org/10.5194/tc-12-1615-2018 |
container_title |
The Cryosphere |
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12 |
container_issue |
5 |
container_start_page |
1615 |
op_container_end_page |
1628 |
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1766103161640058880 |