Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica
Thwaites Glacier (TG), West Antarctica, has been losing mass and retreating rapidly in the past three decades. Here we present a two-dimensional, Full-Stokes (FS) modeling study of the grounding line dynamics and iceberg calving of TG. First, we compare FS with two simplified models, the higher-orde...
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ftcopernicus:oai:publications.copernicus.org:tcd51054 2023-05-15T13:54:27+02:00 Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica Yu, Hongju Rignot, Eric Morlighem, Mathieu Seroussi, Helene 2018-09-26 application/pdf https://doi.org/10.5194/tc-2016-101 https://tc.copernicus.org/preprints/tc-2016-101/ eng eng doi:10.5194/tc-2016-101 https://tc.copernicus.org/preprints/tc-2016-101/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-2016-101 2020-07-20T16:24:08Z Thwaites Glacier (TG), West Antarctica, has been losing mass and retreating rapidly in the past three decades. Here we present a two-dimensional, Full-Stokes (FS) modeling study of the grounding line dynamics and iceberg calving of TG. First, we compare FS with two simplified models, the higher-order (HO) model and the shallow-shelf approximation (SSA) model, to determine the impact of changes in ice shelf basal melt rate on grounding line dynamics. Second, we combine FS with the Linear Elastic Fracture Mechanics (LEFM) theory to simulate crevasse propagation and iceberg calving. In the first experiment, we find that FS requires basal melt rate consistent with remote sensing observations to reach steady state at TG’s current geometry while HO and SSA require unrealistically high basal melt rate. The grounding line of FS is also more sensitive to changes in basal melt rate than HO and SSA. In the second experiment, we find that only FS can produce surface and bottom crevasses that match radar sounding observations of crevasse width and height. We attribute the difference to the non- hydrostatic conditions of ice near the grounding line, which facilitate crevasse formation and are not accounted for in HO and SSA. Additional experiments using FS indicate that iceberg calving is significantly enhanced when surface crevasses exist near the grounding line, when ice shelf is shortened, or when the ice shelf front is undercut. We conclude that FS yields substantial improvements in the description of ice flow dynamics at the grounding line under high basal melt rate and in constraining crevasse formation and iceberg calving. Text Antarc* Antarctica Ice Shelf Thwaites Glacier West Antarctica Copernicus Publications: E-Journals Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Thwaites Glacier (TG), West Antarctica, has been losing mass and retreating rapidly in the past three decades. Here we present a two-dimensional, Full-Stokes (FS) modeling study of the grounding line dynamics and iceberg calving of TG. First, we compare FS with two simplified models, the higher-order (HO) model and the shallow-shelf approximation (SSA) model, to determine the impact of changes in ice shelf basal melt rate on grounding line dynamics. Second, we combine FS with the Linear Elastic Fracture Mechanics (LEFM) theory to simulate crevasse propagation and iceberg calving. In the first experiment, we find that FS requires basal melt rate consistent with remote sensing observations to reach steady state at TG’s current geometry while HO and SSA require unrealistically high basal melt rate. The grounding line of FS is also more sensitive to changes in basal melt rate than HO and SSA. In the second experiment, we find that only FS can produce surface and bottom crevasses that match radar sounding observations of crevasse width and height. We attribute the difference to the non- hydrostatic conditions of ice near the grounding line, which facilitate crevasse formation and are not accounted for in HO and SSA. Additional experiments using FS indicate that iceberg calving is significantly enhanced when surface crevasses exist near the grounding line, when ice shelf is shortened, or when the ice shelf front is undercut. We conclude that FS yields substantial improvements in the description of ice flow dynamics at the grounding line under high basal melt rate and in constraining crevasse formation and iceberg calving. |
format |
Text |
author |
Yu, Hongju Rignot, Eric Morlighem, Mathieu Seroussi, Helene |
spellingShingle |
Yu, Hongju Rignot, Eric Morlighem, Mathieu Seroussi, Helene Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica |
author_facet |
Yu, Hongju Rignot, Eric Morlighem, Mathieu Seroussi, Helene |
author_sort |
Yu, Hongju |
title |
Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica |
title_short |
Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica |
title_full |
Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica |
title_fullStr |
Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica |
title_full_unstemmed |
Full-Stokes modeling of grounding line dynamics, ice melt and iceberg calving for Thwaites Glacier, West Antarctica |
title_sort |
full-stokes modeling of grounding line dynamics, ice melt and iceberg calving for thwaites glacier, west antarctica |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-2016-101 https://tc.copernicus.org/preprints/tc-2016-101/ |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Thwaites Glacier West Antarctica |
geographic_facet |
Thwaites Glacier West Antarctica |
genre |
Antarc* Antarctica Ice Shelf Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Ice Shelf Thwaites Glacier West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2016-101 https://tc.copernicus.org/preprints/tc-2016-101/ |
op_doi |
https://doi.org/10.5194/tc-2016-101 |
_version_ |
1766260339041632256 |