Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes
<jats:title>Abstract</jats:title><jats:p>Using a previously derived treatment of viscoelastic flexure of floating ice shelves, we simulated multiple years of evolution of a single, axisymmetric supraglacial lake when it is subjected to annual fill/drain cycles. Our viscoelastic tre...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/248979 2024-02-04T09:55:43+01:00 Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes Banwell, AF MacAyeal, DR 2015 application/pdf https://www.repository.cam.ac.uk/handle/1810/248979 English eng eng Cambridge University Press (CUP) http://dx.doi.org/10.1017/s0954102015000292 Antarctic Science https://www.repository.cam.ac.uk/handle/1810/248979 Attribution-NonCommercial 2.0 UK: England & Wales http://creativecommons.org/licenses/by-nc/2.0/uk/ Antarctica hydrofracture ice-shelf instability melt ponds viscoelasticity Article 2015 ftunivcam 2024-01-11T23:31:24Z <jats:title>Abstract</jats:title><jats:p>Using a previously derived treatment of viscoelastic flexure of floating ice shelves, we simulated multiple years of evolution of a single, axisymmetric supraglacial lake when it is subjected to annual fill/drain cycles. Our viscoelastic treatment follows the assumptions of the well-known thin-beam and thin-plate analysis but, crucially, also covers power-law creep rheology. As the ice-shelf surface does not completely return to its un-flexed position after a 1-year fill/drain cycle, the lake basin deepens with each successive cycle. This deepening process is significantly amplified when lake-bottom ablation is taken into account. We evaluate the timescale over which a typical lake reaches a sufficient depth such that ice-shelf fracture can occur well beyond the lake itself in response to lake filling/drainage. We show that, although this is unlikely during one fill/drain cycle, fracture is possible after multiple years assuming surface meltwater availability is unlimited. This extended zone of potential fracture implies that flexural stresses in response to a single lake filling/drainage event can cause neighbouring lakes to drain, which, in turn, can cause lakes farther afield to drain. Such self-stimulating behaviour may have accounted for the sudden, widespread appearance of a fracture system that drove the Larsen B Ice Shelf to break-up in 2002.</jats:p> Alison Banwell acknowledges the support of an Antarctic Science International Bursary from Antarctic Science Ltd. and a Bowring Junior Research Fellowship from St Catharine’s College, Cambridge. This is the author accepted manuscript. The final version is available from Cambridge University Press via http://dx.doi.org/10.1017/S0954102015000292 Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Shelf Ice Shelves Apollo - University of Cambridge Repository Antarctic Single Lake ENVELOPE(-99.525,-99.525,58.442,58.442) |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Antarctica hydrofracture ice-shelf instability melt ponds viscoelasticity |
spellingShingle |
Antarctica hydrofracture ice-shelf instability melt ponds viscoelasticity Banwell, AF MacAyeal, DR Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes |
topic_facet |
Antarctica hydrofracture ice-shelf instability melt ponds viscoelasticity |
description |
<jats:title>Abstract</jats:title><jats:p>Using a previously derived treatment of viscoelastic flexure of floating ice shelves, we simulated multiple years of evolution of a single, axisymmetric supraglacial lake when it is subjected to annual fill/drain cycles. Our viscoelastic treatment follows the assumptions of the well-known thin-beam and thin-plate analysis but, crucially, also covers power-law creep rheology. As the ice-shelf surface does not completely return to its un-flexed position after a 1-year fill/drain cycle, the lake basin deepens with each successive cycle. This deepening process is significantly amplified when lake-bottom ablation is taken into account. We evaluate the timescale over which a typical lake reaches a sufficient depth such that ice-shelf fracture can occur well beyond the lake itself in response to lake filling/drainage. We show that, although this is unlikely during one fill/drain cycle, fracture is possible after multiple years assuming surface meltwater availability is unlimited. This extended zone of potential fracture implies that flexural stresses in response to a single lake filling/drainage event can cause neighbouring lakes to drain, which, in turn, can cause lakes farther afield to drain. Such self-stimulating behaviour may have accounted for the sudden, widespread appearance of a fracture system that drove the Larsen B Ice Shelf to break-up in 2002.</jats:p> Alison Banwell acknowledges the support of an Antarctic Science International Bursary from Antarctic Science Ltd. and a Bowring Junior Research Fellowship from St Catharine’s College, Cambridge. This is the author accepted manuscript. The final version is available from Cambridge University Press via http://dx.doi.org/10.1017/S0954102015000292 |
format |
Article in Journal/Newspaper |
author |
Banwell, AF MacAyeal, DR |
author_facet |
Banwell, AF MacAyeal, DR |
author_sort |
Banwell, AF |
title |
Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes |
title_short |
Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes |
title_full |
Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes |
title_fullStr |
Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes |
title_full_unstemmed |
Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes |
title_sort |
ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes |
publisher |
Cambridge University Press (CUP) |
publishDate |
2015 |
url |
https://www.repository.cam.ac.uk/handle/1810/248979 |
long_lat |
ENVELOPE(-99.525,-99.525,58.442,58.442) |
geographic |
Antarctic Single Lake |
geographic_facet |
Antarctic Single Lake |
genre |
Antarc* Antarctic Antarctica Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Antarctica Ice Shelf Ice Shelves |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/248979 |
op_rights |
Attribution-NonCommercial 2.0 UK: England & Wales http://creativecommons.org/licenses/by-nc/2.0/uk/ |
_version_ |
1789959833814827008 |