The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica
Ice shelf fractures frequently terminate where they encounter suture zones, regions of material heterogeneity that form between meteoric inflows in ice shelves. This heterogeneity can consist of marine ice, meteoric ice with modified rheological properties, or the presence of fractures. Here, we use...
Published in: | Journal of Geophysical Research: Earth Surface |
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Online Access: | https://doi.org/10.1002/2013Jf002935 http://infoscience.epfl.ch/record/199066 |
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ftinfoscience:oai:infoscience.tind.io:199066 2023-05-15T13:48:05+02:00 The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica Mcgrath, Daniel Steffen, Konrad Holland, Paul R. Scambos, Ted Rajaram, Harihar Abdalati, Waleed Rignot, Eric 2014-05-26T17:28:46Z https://doi.org/10.1002/2013Jf002935 http://infoscience.epfl.ch/record/199066 unknown Washington, Amer Geophysical Union doi:10.1002/2013Jf002935 ISI:000334362800011 http://infoscience.epfl.ch/record/199066 http://infoscience.epfl.ch/record/199066 Text 2014 ftinfoscience https://doi.org/10.1002/2013Jf002935 2023-02-13T22:20:49Z Ice shelf fractures frequently terminate where they encounter suture zones, regions of material heterogeneity that form between meteoric inflows in ice shelves. This heterogeneity can consist of marine ice, meteoric ice with modified rheological properties, or the presence of fractures. Here, we use radar observations on the Larsen C Ice Shelf, Antarctica, to investigate (i) the termination of a 25km long rift in the Churchill Peninsula suture zone, which was found to contain similar to 60m of accreted marine ice, and (ii) the along-flow evolution of a suture zone originating at Cole Peninsula. We determine a steady state field of basal melting/freezing rates and apply it to a flowline model to delineate the along-flow evolution of layers within the ice shelf. The thickening surface wedge of locally accumulated meteoric ice, which likely has limited lateral variation in its mechanical properties, accounts for similar to 60% of the total ice thickness near the calving front. Thus, we infer that the lower similar to 40% of the ice column and the material heterogeneities present there are responsible for resisting fracture propagation and thereby delaying tabular calving events, as demonstrated in the >40year time series leading up to the 2004/2005 calving event for Larsen C. This likely represents a highly sensitive aspect of ice shelf stability, as changes in the oceanic forcing may lead to the loss of this heterogeneity. Text Antarc* Antarctica Ice Shelf Ice Shelves EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) Churchill Peninsula ENVELOPE(-62.781,-62.781,-66.440,-66.440) Cole peninsula ENVELOPE(-63.969,-63.969,-66.845,-66.845) Journal of Geophysical Research: Earth Surface 119 3 588 602 |
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EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) |
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ftinfoscience |
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description |
Ice shelf fractures frequently terminate where they encounter suture zones, regions of material heterogeneity that form between meteoric inflows in ice shelves. This heterogeneity can consist of marine ice, meteoric ice with modified rheological properties, or the presence of fractures. Here, we use radar observations on the Larsen C Ice Shelf, Antarctica, to investigate (i) the termination of a 25km long rift in the Churchill Peninsula suture zone, which was found to contain similar to 60m of accreted marine ice, and (ii) the along-flow evolution of a suture zone originating at Cole Peninsula. We determine a steady state field of basal melting/freezing rates and apply it to a flowline model to delineate the along-flow evolution of layers within the ice shelf. The thickening surface wedge of locally accumulated meteoric ice, which likely has limited lateral variation in its mechanical properties, accounts for similar to 60% of the total ice thickness near the calving front. Thus, we infer that the lower similar to 40% of the ice column and the material heterogeneities present there are responsible for resisting fracture propagation and thereby delaying tabular calving events, as demonstrated in the >40year time series leading up to the 2004/2005 calving event for Larsen C. This likely represents a highly sensitive aspect of ice shelf stability, as changes in the oceanic forcing may lead to the loss of this heterogeneity. |
format |
Text |
author |
Mcgrath, Daniel Steffen, Konrad Holland, Paul R. Scambos, Ted Rajaram, Harihar Abdalati, Waleed Rignot, Eric |
spellingShingle |
Mcgrath, Daniel Steffen, Konrad Holland, Paul R. Scambos, Ted Rajaram, Harihar Abdalati, Waleed Rignot, Eric The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica |
author_facet |
Mcgrath, Daniel Steffen, Konrad Holland, Paul R. Scambos, Ted Rajaram, Harihar Abdalati, Waleed Rignot, Eric |
author_sort |
Mcgrath, Daniel |
title |
The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica |
title_short |
The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica |
title_full |
The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica |
title_fullStr |
The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica |
title_full_unstemmed |
The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica |
title_sort |
structure and effect of suture zones in the larsen c ice shelf, antarctica |
publisher |
Washington, Amer Geophysical Union |
publishDate |
2014 |
url |
https://doi.org/10.1002/2013Jf002935 http://infoscience.epfl.ch/record/199066 |
long_lat |
ENVELOPE(-62.781,-62.781,-66.440,-66.440) ENVELOPE(-63.969,-63.969,-66.845,-66.845) |
geographic |
Churchill Peninsula Cole peninsula |
geographic_facet |
Churchill Peninsula Cole peninsula |
genre |
Antarc* Antarctica Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves |
op_source |
http://infoscience.epfl.ch/record/199066 |
op_relation |
doi:10.1002/2013Jf002935 ISI:000334362800011 http://infoscience.epfl.ch/record/199066 |
op_doi |
https://doi.org/10.1002/2013Jf002935 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
119 |
container_issue |
3 |
container_start_page |
588 |
op_container_end_page |
602 |
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1766248578735407104 |