The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers
© 2015 Elsevier B.V. Following the 2002 disintegration of the northern and central parts of the Larsen B Ice Shelf, the tributary glaciers of the southern surviving part initially appeared relatively unchanged and hence assumed to be buttressed sufficiently by the remnant ice shelf. Here, we modify...
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ftcdlib:qt7m1405b0 2023-05-15T16:17:24+02:00 The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers Khazendar, A Borstad, CP Scheuchl, B Rignot, E Seroussi, H 199 - 210 2015-06-01 application/pdf http://www.escholarship.org/uc/item/7m1405b0 english eng eScholarship, University of California qt7m1405b0 http://www.escholarship.org/uc/item/7m1405b0 Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ CC-BY Khazendar, A; Borstad, CP; Scheuchl, B; Rignot, E; & Seroussi, H. (2015). The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers. Earth and Planetary Science Letters, 419, 199 - 210. doi:10.1016/j.epsl.2015.03.014. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/7m1405b0 article 2015 ftcdlib https://doi.org/10.1016/j.epsl.2015.03.014 2018-01-05T23:52:27Z © 2015 Elsevier B.V. Following the 2002 disintegration of the northern and central parts of the Larsen B Ice Shelf, the tributary glaciers of the southern surviving part initially appeared relatively unchanged and hence assumed to be buttressed sufficiently by the remnant ice shelf. Here, we modify this perception with observations from IceBridge altimetry and InSAR-inferred ice flow speeds. Our analyses show that the surfaces of Leppard and Flask glaciers directly upstream from their grounding lines lowered by 15 to 20 m in the period 2002-2011. The thinning appears to be dynamic as the flow of both glaciers and the remnant ice shelf accelerated in the same period. Flask Glacier started accelerating even before the 2002 disintegration, increasing its flow speed by ~55% between 1997 and 2012. Starbuck Glacier meanwhile did not change much. We hypothesize that the different evolutions of the three glaciers are related to their dissimilar bed topographies and degrees of grounding. We apply numerical modeling and data assimilation that show these changes to be accompanied by a reduction in the buttressing afforded by the remnant ice shelf, a weakening of the shear zones between its flow units and an increase in its fracture. The fast flowing northwestern part of the remnant ice shelf exhibits increasing fragmentation, while the stagnant southeastern part seems to be prone to the formation of large rifts, some of which we show have delimited successive calving events. A large rift only 12 km downstream from the grounding line is currently traversing the stagnant part of the ice shelf, defining the likely front of the next large calving event. We propose that the flow acceleration, ice front retreat and enhanced fracture of the remnant Larsen B Ice Shelf presage its approaching demise. Article in Journal/Newspaper Flask Glacier Ice Shelf University of California: eScholarship Flask Glacier ENVELOPE(-62.792,-62.792,-65.762,-65.762) Starbuck Glacier ENVELOPE(-62.416,-62.416,-65.616,-65.616) Earth and Planetary Science Letters 419 199 210 |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
description |
© 2015 Elsevier B.V. Following the 2002 disintegration of the northern and central parts of the Larsen B Ice Shelf, the tributary glaciers of the southern surviving part initially appeared relatively unchanged and hence assumed to be buttressed sufficiently by the remnant ice shelf. Here, we modify this perception with observations from IceBridge altimetry and InSAR-inferred ice flow speeds. Our analyses show that the surfaces of Leppard and Flask glaciers directly upstream from their grounding lines lowered by 15 to 20 m in the period 2002-2011. The thinning appears to be dynamic as the flow of both glaciers and the remnant ice shelf accelerated in the same period. Flask Glacier started accelerating even before the 2002 disintegration, increasing its flow speed by ~55% between 1997 and 2012. Starbuck Glacier meanwhile did not change much. We hypothesize that the different evolutions of the three glaciers are related to their dissimilar bed topographies and degrees of grounding. We apply numerical modeling and data assimilation that show these changes to be accompanied by a reduction in the buttressing afforded by the remnant ice shelf, a weakening of the shear zones between its flow units and an increase in its fracture. The fast flowing northwestern part of the remnant ice shelf exhibits increasing fragmentation, while the stagnant southeastern part seems to be prone to the formation of large rifts, some of which we show have delimited successive calving events. A large rift only 12 km downstream from the grounding line is currently traversing the stagnant part of the ice shelf, defining the likely front of the next large calving event. We propose that the flow acceleration, ice front retreat and enhanced fracture of the remnant Larsen B Ice Shelf presage its approaching demise. |
format |
Article in Journal/Newspaper |
author |
Khazendar, A Borstad, CP Scheuchl, B Rignot, E Seroussi, H |
spellingShingle |
Khazendar, A Borstad, CP Scheuchl, B Rignot, E Seroussi, H The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers |
author_facet |
Khazendar, A Borstad, CP Scheuchl, B Rignot, E Seroussi, H |
author_sort |
Khazendar, A |
title |
The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers |
title_short |
The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers |
title_full |
The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers |
title_fullStr |
The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers |
title_full_unstemmed |
The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers |
title_sort |
evolving instability of the remnant larsen b ice shelf and its tributary glaciers |
publisher |
eScholarship, University of California |
publishDate |
2015 |
url |
http://www.escholarship.org/uc/item/7m1405b0 |
op_coverage |
199 - 210 |
long_lat |
ENVELOPE(-62.792,-62.792,-65.762,-65.762) ENVELOPE(-62.416,-62.416,-65.616,-65.616) |
geographic |
Flask Glacier Starbuck Glacier |
geographic_facet |
Flask Glacier Starbuck Glacier |
genre |
Flask Glacier Ice Shelf |
genre_facet |
Flask Glacier Ice Shelf |
op_source |
Khazendar, A; Borstad, CP; Scheuchl, B; Rignot, E; & Seroussi, H. (2015). The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers. Earth and Planetary Science Letters, 419, 199 - 210. doi:10.1016/j.epsl.2015.03.014. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/7m1405b0 |
op_relation |
qt7m1405b0 http://www.escholarship.org/uc/item/7m1405b0 |
op_rights |
Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.epsl.2015.03.014 |
container_title |
Earth and Planetary Science Letters |
container_volume |
419 |
container_start_page |
199 |
op_container_end_page |
210 |
_version_ |
1766003250986745856 |