Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups
Satellite remote sensing observations of three break-up events in 2008 for the Wilkins Ice Shelf (28 February to 6 March, 27 May to 31 May, and 28 June to mid-July) provide unprecedented detail of ice shelf calving during rapid break-up. The observations reveal that the Wilkins break-ups occur throu...
Published in: | Earth and Planetary Science Letters |
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ftchengkunguniv:oai:ir.lib.ncku.edu.tw:987654321/86720 2023-05-15T13:38:42+02:00 Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups Scambos, Ted Fricker, Helen Amanda Liu, Cheng-Chien Bohlander, Jennifer Fastook, James Sargent, Aitbala Massom, Robert Wu, An-Ming Department of Earth Sciences 2009-04-15 298 bytes application/octet-stream https://doi.org/10.1016/j.epsl.2008.12.027 http://ir.lib.ncku.edu.tw/handle/987654321/86720 Eng en_US eng Elsevier Earth and Planetary Science Letters, Vol.280, No.1-4, pp.51-60 Antarctica ice shelves Wilkins ice shelf climate change Formosat-2 ice modeling ice shelf break-up article 2009 ftchengkunguniv https://doi.org/10.1016/j.epsl.2008.12.027 2016-05-22T06:56:11Z Satellite remote sensing observations of three break-up events in 2008 for the Wilkins Ice Shelf (28 February to 6 March, 27 May to 31 May, and 28 June to mid-July) provide unprecedented detail of ice shelf calving during rapid break-up. The observations reveal that the Wilkins break-ups occur through a distinctive type of shelf calving, which we term 'disintegration', as well as more typical rifting and calving. Here we focus on the disintegration process, which is characterized by repeated rapid fracturing that creates narrow ice-edge-parallel blocks, with subsequent block toppling and fragmentation forming an expanding iceberg and ice rubble mass. We use these data to develop and test a model of floating ice plate disintegration in which ice plate bending stresses at the ice front arising from buoyancy forces can lead to runaway calving when free (mobile) water is available. High-resolution satellite images and laser altimetry of the first break-up event provide details of fracture spacings, ice thicknesses, and plate bending profiles that agree well with our model predictions. We suggest that surface or near-surface meltwater is the main pre-condition for disintegration, and that hydro-fracture is the main mechanism. Brine layers from near-waterline brine infiltration can support a similar process, but this is less effective unless regional ice stress patterns contribute to the net stress available at the crack tip for fracturing. A combination of brine-enhanced fracturing and changing internal net extensional stresses was the likely mechanism behind the latter two Wilkins events. (C) 2008 Elsevier B.V. All rights reserved. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Ice Shelves Wilkins Ice Shelf National Cheng Kung University: NCKU Institutional Repository Wilkins ENVELOPE(59.326,59.326,-67.248,-67.248) Wilkins Ice Shelf ENVELOPE(-72.500,-72.500,-70.416,-70.416) Earth and Planetary Science Letters 280 1-4 51 60 |
institution |
Open Polar |
collection |
National Cheng Kung University: NCKU Institutional Repository |
op_collection_id |
ftchengkunguniv |
language |
English |
topic |
Antarctica ice shelves Wilkins ice shelf climate change Formosat-2 ice modeling ice shelf break-up |
spellingShingle |
Antarctica ice shelves Wilkins ice shelf climate change Formosat-2 ice modeling ice shelf break-up Scambos, Ted Fricker, Helen Amanda Liu, Cheng-Chien Bohlander, Jennifer Fastook, James Sargent, Aitbala Massom, Robert Wu, An-Ming Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups |
topic_facet |
Antarctica ice shelves Wilkins ice shelf climate change Formosat-2 ice modeling ice shelf break-up |
description |
Satellite remote sensing observations of three break-up events in 2008 for the Wilkins Ice Shelf (28 February to 6 March, 27 May to 31 May, and 28 June to mid-July) provide unprecedented detail of ice shelf calving during rapid break-up. The observations reveal that the Wilkins break-ups occur through a distinctive type of shelf calving, which we term 'disintegration', as well as more typical rifting and calving. Here we focus on the disintegration process, which is characterized by repeated rapid fracturing that creates narrow ice-edge-parallel blocks, with subsequent block toppling and fragmentation forming an expanding iceberg and ice rubble mass. We use these data to develop and test a model of floating ice plate disintegration in which ice plate bending stresses at the ice front arising from buoyancy forces can lead to runaway calving when free (mobile) water is available. High-resolution satellite images and laser altimetry of the first break-up event provide details of fracture spacings, ice thicknesses, and plate bending profiles that agree well with our model predictions. We suggest that surface or near-surface meltwater is the main pre-condition for disintegration, and that hydro-fracture is the main mechanism. Brine layers from near-waterline brine infiltration can support a similar process, but this is less effective unless regional ice stress patterns contribute to the net stress available at the crack tip for fracturing. A combination of brine-enhanced fracturing and changing internal net extensional stresses was the likely mechanism behind the latter two Wilkins events. (C) 2008 Elsevier B.V. All rights reserved. |
author2 |
Department of Earth Sciences |
format |
Article in Journal/Newspaper |
author |
Scambos, Ted Fricker, Helen Amanda Liu, Cheng-Chien Bohlander, Jennifer Fastook, James Sargent, Aitbala Massom, Robert Wu, An-Ming |
author_facet |
Scambos, Ted Fricker, Helen Amanda Liu, Cheng-Chien Bohlander, Jennifer Fastook, James Sargent, Aitbala Massom, Robert Wu, An-Ming |
author_sort |
Scambos, Ted |
title |
Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups |
title_short |
Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups |
title_full |
Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups |
title_fullStr |
Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups |
title_full_unstemmed |
Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups |
title_sort |
ice shelf disintegration by plate bending and hydro-fracture: satellite observations and model results of the 2008 wilkins ice shelf break-ups |
publisher |
Elsevier |
publishDate |
2009 |
url |
https://doi.org/10.1016/j.epsl.2008.12.027 http://ir.lib.ncku.edu.tw/handle/987654321/86720 |
long_lat |
ENVELOPE(59.326,59.326,-67.248,-67.248) ENVELOPE(-72.500,-72.500,-70.416,-70.416) |
geographic |
Wilkins Wilkins Ice Shelf |
geographic_facet |
Wilkins Wilkins Ice Shelf |
genre |
Antarc* Antarctica Ice Shelf Ice Shelves Wilkins Ice Shelf |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves Wilkins Ice Shelf |
op_relation |
Earth and Planetary Science Letters, Vol.280, No.1-4, pp.51-60 |
op_doi |
https://doi.org/10.1016/j.epsl.2008.12.027 |
container_title |
Earth and Planetary Science Letters |
container_volume |
280 |
container_issue |
1-4 |
container_start_page |
51 |
op_container_end_page |
60 |
_version_ |
1766110116372807680 |