Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica

ABSTRACT Data showing velocity changes on the Brunt Ice Shelf (BIS), Antarctica, over the last 55 years are presented and analysed. During this period no large-scale calving events took place and the ice shelf gradually grew in size. Ice flow velocities, however, fluctuated greatly, increasing twofo...

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Published in:Journal of Glaciology
Main Authors: GUDMUNDSSON, G. HILMAR, DE RYDT, JAN, NAGLER, THOMAS
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2016
Subjects:
Online Access:http://dx.doi.org/10.1017/jog.2016.132
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001325
id crcambridgeupr:10.1017/jog.2016.132
record_format openpolar
spelling crcambridgeupr:10.1017/jog.2016.132 2024-06-23T07:45:40+00:00 Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica GUDMUNDSSON, G. HILMAR DE RYDT, JAN NAGLER, THOMAS 2016 http://dx.doi.org/10.1017/jog.2016.132 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001325 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by-nc-nd/4.0/ Journal of Glaciology volume 63, issue 237, page 164-175 ISSN 0022-1430 1727-5652 journal-article 2016 crcambridgeupr https://doi.org/10.1017/jog.2016.132 2024-05-29T08:08:54Z ABSTRACT Data showing velocity changes on the Brunt Ice Shelf (BIS), Antarctica, over the last 55 years are presented and analysed. During this period no large-scale calving events took place and the ice shelf gradually grew in size. Ice flow velocities, however, fluctuated greatly, increasing twofold between 1970 and 2000, then decreasing again to previous levels by 2012 after which velocities started to increase yet again. In the observational period, velocity changes in the order of 10% a −1 have commonly been observed, and currently velocities are increasing at this rate. By modelling the ice flow numerically, we explore potential causes for the observed changes in velocity. We find that a loss of mechanical contact between the BIS and the McDonald Ice Rumples following a local calving event in 1971 would explain both the increase and the subsequent decrease in ice velocities. Other explanations involving enlargement of observed rift structures are discounted as the effects on ice flow are found to be too small and the spatial pattern of velocity change inconsistent with data. The most recent phase of acceleration remains unexplained but may potentially be related to a recent re-activation of a known rift structure within the BIS. Article in Journal/Newspaper Antarc* Antarctica Brunt Ice Shelf Ice Shelf Journal of Glaciology Cambridge University Press Brunt Ice Shelf ENVELOPE(-22.500,-22.500,-74.750,-74.750) McDonald Ice Rumples ENVELOPE(-26.352,-26.352,-75.458,-75.458) Journal of Glaciology 63 237 164 175
institution Open Polar
collection Cambridge University Press
op_collection_id crcambridgeupr
language English
description ABSTRACT Data showing velocity changes on the Brunt Ice Shelf (BIS), Antarctica, over the last 55 years are presented and analysed. During this period no large-scale calving events took place and the ice shelf gradually grew in size. Ice flow velocities, however, fluctuated greatly, increasing twofold between 1970 and 2000, then decreasing again to previous levels by 2012 after which velocities started to increase yet again. In the observational period, velocity changes in the order of 10% a −1 have commonly been observed, and currently velocities are increasing at this rate. By modelling the ice flow numerically, we explore potential causes for the observed changes in velocity. We find that a loss of mechanical contact between the BIS and the McDonald Ice Rumples following a local calving event in 1971 would explain both the increase and the subsequent decrease in ice velocities. Other explanations involving enlargement of observed rift structures are discounted as the effects on ice flow are found to be too small and the spatial pattern of velocity change inconsistent with data. The most recent phase of acceleration remains unexplained but may potentially be related to a recent re-activation of a known rift structure within the BIS.
format Article in Journal/Newspaper
author GUDMUNDSSON, G. HILMAR
DE RYDT, JAN
NAGLER, THOMAS
spellingShingle GUDMUNDSSON, G. HILMAR
DE RYDT, JAN
NAGLER, THOMAS
Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica
author_facet GUDMUNDSSON, G. HILMAR
DE RYDT, JAN
NAGLER, THOMAS
author_sort GUDMUNDSSON, G. HILMAR
title Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica
title_short Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica
title_full Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica
title_fullStr Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica
title_full_unstemmed Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica
title_sort five decades of strong temporal variability in the flow of brunt ice shelf, antarctica
publisher Cambridge University Press (CUP)
publishDate 2016
url http://dx.doi.org/10.1017/jog.2016.132
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001325
long_lat ENVELOPE(-22.500,-22.500,-74.750,-74.750)
ENVELOPE(-26.352,-26.352,-75.458,-75.458)
geographic Brunt Ice Shelf
McDonald Ice Rumples
geographic_facet Brunt Ice Shelf
McDonald Ice Rumples
genre Antarc*
Antarctica
Brunt Ice Shelf
Ice Shelf
Journal of Glaciology
genre_facet Antarc*
Antarctica
Brunt Ice Shelf
Ice Shelf
Journal of Glaciology
op_source Journal of Glaciology
volume 63, issue 237, page 164-175
ISSN 0022-1430 1727-5652
op_rights http://creativecommons.org/licenses/by-nc-nd/4.0/
op_doi https://doi.org/10.1017/jog.2016.132
container_title Journal of Glaciology
container_volume 63
container_issue 237
container_start_page 164
op_container_end_page 175
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