Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics

Abstract. Thwaites Glacier (TG), West Antarctica, has been losing mass and retreating rapidly in the past few decades. Here, we present a study of its calving dynamics combining a two-dimensional flowband Full Stokes (FS) model of its viscous flow with linear elastic fracture mechanics (LEFM) theory...

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Main Authors: Yu, Hongju, Rignot, Eric, Morlighem, Mathieu, Seroussi, Helene
Format: Article in Journal/Newspaper
Language:unknown
Published: eScholarship, University of California 2016
Subjects:
Online Access:https://escholarship.org/uc/item/1d5221cq
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spelling ftcdlib:oai:escholarship.org:ark:/13030/qt1d5221cq 2023-09-05T13:15:17+02:00 Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics Yu, Hongju Rignot, Eric Morlighem, Mathieu Seroussi, Helene 2016-11-09 application/pdf https://escholarship.org/uc/item/1d5221cq unknown eScholarship, University of California qt1d5221cq https://escholarship.org/uc/item/1d5221cq public article 2016 ftcdlib 2023-08-14T18:03:17Z Abstract. Thwaites Glacier (TG), West Antarctica, has been losing mass and retreating rapidly in the past few decades. Here, we present a study of its calving dynamics combining a two-dimensional flowband Full Stokes (FS) model of its viscous flow with linear elastic fracture mechanics (LEFM) theory to model crevasse propagation and ice fracturing. We compare the results with those obtained with the higher-order (HO) and the shallow-shelf approximation (SSA) models coupled with LEFM. We find that FS/LEFM produces surface and bottom crevasses that match the distribution of crevasse depth and width observed from NASA's Operation IceBridge radar depth sounders, whereas HO/LEFM and SSA/LEFM do not generate crevasses that match observations. We attribute the difference to the non-hydrostatic condition of ice near the grounding line, which facilitates crevasse formation, and is accounted for by the FS model but not by the HO or SSA model. We also find that calving is enhanced when pre-existing surface crevasses are present, when the ice shelf is shortened or when the ice shelf front is undercut. The role of undercutting depends on the time scale of calving events. It is more prominent for glaciers with rapid calving rates than glaciers with slow calving rates. Glaciers extending into a shorter ice shelf are more vulnerable to calving than glaciers developing a long ice shelf, especially as the ice front retreats close to the grounding line region, which leads to a positive feedback. We conclude that the FS/LEFM combination yields substantial improvements in capturing the stress field near the grounding line for constraining crevasse formation and iceberg calving. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Thwaites Glacier West Antarctica University of California: eScholarship West Antarctica Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500)
institution Open Polar
collection University of California: eScholarship
op_collection_id ftcdlib
language unknown
description Abstract. Thwaites Glacier (TG), West Antarctica, has been losing mass and retreating rapidly in the past few decades. Here, we present a study of its calving dynamics combining a two-dimensional flowband Full Stokes (FS) model of its viscous flow with linear elastic fracture mechanics (LEFM) theory to model crevasse propagation and ice fracturing. We compare the results with those obtained with the higher-order (HO) and the shallow-shelf approximation (SSA) models coupled with LEFM. We find that FS/LEFM produces surface and bottom crevasses that match the distribution of crevasse depth and width observed from NASA's Operation IceBridge radar depth sounders, whereas HO/LEFM and SSA/LEFM do not generate crevasses that match observations. We attribute the difference to the non-hydrostatic condition of ice near the grounding line, which facilitates crevasse formation, and is accounted for by the FS model but not by the HO or SSA model. We also find that calving is enhanced when pre-existing surface crevasses are present, when the ice shelf is shortened or when the ice shelf front is undercut. The role of undercutting depends on the time scale of calving events. It is more prominent for glaciers with rapid calving rates than glaciers with slow calving rates. Glaciers extending into a shorter ice shelf are more vulnerable to calving than glaciers developing a long ice shelf, especially as the ice front retreats close to the grounding line region, which leads to a positive feedback. We conclude that the FS/LEFM combination yields substantial improvements in capturing the stress field near the grounding line for constraining crevasse formation and iceberg calving.
format Article in Journal/Newspaper
author Yu, Hongju
Rignot, Eric
Morlighem, Mathieu
Seroussi, Helene
spellingShingle Yu, Hongju
Rignot, Eric
Morlighem, Mathieu
Seroussi, Helene
Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics
author_facet Yu, Hongju
Rignot, Eric
Morlighem, Mathieu
Seroussi, Helene
author_sort Yu, Hongju
title Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics
title_short Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics
title_full Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics
title_fullStr Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics
title_full_unstemmed Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics
title_sort iceberg calving of thwaites glacier, west antarctica: full-stokes modeling combined with linear elastic fracture mechanics
publisher eScholarship, University of California
publishDate 2016
url https://escholarship.org/uc/item/1d5221cq
long_lat ENVELOPE(-106.750,-106.750,-75.500,-75.500)
geographic West Antarctica
Thwaites Glacier
geographic_facet West Antarctica
Thwaites Glacier
genre Antarc*
Antarctica
Ice Shelf
Thwaites Glacier
West Antarctica
genre_facet Antarc*
Antarctica
Ice Shelf
Thwaites Glacier
West Antarctica
op_relation qt1d5221cq
https://escholarship.org/uc/item/1d5221cq
op_rights public
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