Iceberg calving of Thwaites Glacier, West Antarctica: full-Stokes modeling combined with linear elastic fracture mechanics
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 flow-band full-Stokes (FS) model of its viscous flow with linear elastic fracture mechanics (LEFM) theory to model...
Main Authors: | , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
eScholarship, University of California
2017
|
Subjects: | |
Online Access: | https://escholarship.org/uc/item/9cd7d1g1 |
id |
ftcdlib:oai:escholarship.org:ark:/13030/qt9cd7d1g1 |
---|---|
record_format |
openpolar |
spelling |
ftcdlib:oai:escholarship.org:ark:/13030/qt9cd7d1g1 2023-06-18T03:36:56+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 1283 - 1296 2017-05-30 https://escholarship.org/uc/item/9cd7d1g1 unknown eScholarship, University of California qt9cd7d1g1 https://escholarship.org/uc/item/9cd7d1g1 public The Cryosphere, vol 11, iss 3 Climate Action Oceanography Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences article 2017 ftcdlib 2023-06-05T18:00:31Z 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 flow-band 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 are consistent with the distribution of depth and width of surface and bottom crevasses observed by NASA's Operation IceBridge radar depth sounder and laser altimeter, whereas HO/LEFM and SSA/LEFM do not generate crevasses that are consistent with observations. We attribute the difference to the nonhydrostatic 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 models. We 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 timescale of calving events. It is more prominent for glaciers with rapid calving rates than for 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 to calving events. We conclude that the FS/LEFM combination yields substantial improvements in capturing the stress field near the grounding line of a glacier for constraining crevasse formation and iceberg calving. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf The Cryosphere 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 |
topic |
Climate Action Oceanography Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences |
spellingShingle |
Climate Action Oceanography Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences Yu, Hongju Rignot, Eric Morlighem, Mathieu Seroussi, Helene Iceberg calving of Thwaites Glacier, West Antarctica: full-Stokes modeling combined with linear elastic fracture mechanics |
topic_facet |
Climate Action Oceanography Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences |
description |
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 flow-band 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 are consistent with the distribution of depth and width of surface and bottom crevasses observed by NASA's Operation IceBridge radar depth sounder and laser altimeter, whereas HO/LEFM and SSA/LEFM do not generate crevasses that are consistent with observations. We attribute the difference to the nonhydrostatic 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 models. We 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 timescale of calving events. It is more prominent for glaciers with rapid calving rates than for 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 to calving events. We conclude that the FS/LEFM combination yields substantial improvements in capturing the stress field near the grounding line of a glacier for constraining crevasse formation and iceberg calving. |
format |
Article in Journal/Newspaper |
author |
Yu, Hongju Rignot, Eric Morlighem, Mathieu Seroussi, Helene |
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 |
2017 |
url |
https://escholarship.org/uc/item/9cd7d1g1 |
op_coverage |
1283 - 1296 |
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 The Cryosphere Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Ice Shelf The Cryosphere Thwaites Glacier West Antarctica |
op_source |
The Cryosphere, vol 11, iss 3 |
op_relation |
qt9cd7d1g1 https://escholarship.org/uc/item/9cd7d1g1 |
op_rights |
public |
_version_ |
1769009106945835008 |