Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet
Abstract Radio‐echo sounding (RES) shows large‐scale englacial stratigraphic folds are ubiquitous in Greenland's ice sheet. However, there is no consensus yet on how these folds form. Here, we use the full‐Stokes code Underworld2 to simulate ice movements in three‐dimensional convergent flow, m...
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ftdoajarticles:oai:doaj.org/article:55100ba1a1654be090a43728021fea10 2024-09-15T18:12:13+00:00 Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet Yu Zhang Till Sachau Steven Franke Haibin Yang Dian Li Ilka Weikusat Paul D. Bons 2024-08-01T00:00:00Z https://doi.org/10.1029/2024GL109492 https://doaj.org/article/55100ba1a1654be090a43728021fea10 EN eng Wiley https://doi.org/10.1029/2024GL109492 https://doaj.org/toc/0094-8276 https://doaj.org/toc/1944-8007 1944-8007 0094-8276 doi:10.1029/2024GL109492 https://doaj.org/article/55100ba1a1654be090a43728021fea10 Geophysical Research Letters, Vol 51, Iss 16, Pp n/a-n/a (2024) ice modeling fold anisotropy polar ice sheet non‐linear viscosity bedrock topography Geophysics. Cosmic physics QC801-809 article 2024 ftdoajarticles https://doi.org/10.1029/2024GL109492 2024-09-02T15:34:38Z Abstract Radio‐echo sounding (RES) shows large‐scale englacial stratigraphic folds are ubiquitous in Greenland's ice sheet. However, there is no consensus yet on how these folds form. Here, we use the full‐Stokes code Underworld2 to simulate ice movements in three‐dimensional convergent flow, mainly considering ice anisotropy due to a crystallographic preferred orientation, vertical viscosity and density gradients in ice layers, and bedrock topography. Our simulated folds show complex patterns and are classified into: large‐scale folds (>100 m amplitude), small‐scale folds (<<100 m) and basal‐shear folds. The amplitudes of large‐scale folds tend to be at their maximum in the middle of the ice column or just below, in accordance with observations in RES data. We conclude that ice anisotropy amplifies the perturbations in ice layers (mainly due to bedrock topography) into large‐scale folds during flow. Density differences between the warm deep ice and cold ice above may enhance fold amplification. Article in Journal/Newspaper Ice Sheet Directory of Open Access Journals: DOAJ Articles Geophysical Research Letters 51 16 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
ice modeling fold anisotropy polar ice sheet non‐linear viscosity bedrock topography Geophysics. Cosmic physics QC801-809 |
spellingShingle |
ice modeling fold anisotropy polar ice sheet non‐linear viscosity bedrock topography Geophysics. Cosmic physics QC801-809 Yu Zhang Till Sachau Steven Franke Haibin Yang Dian Li Ilka Weikusat Paul D. Bons Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet |
topic_facet |
ice modeling fold anisotropy polar ice sheet non‐linear viscosity bedrock topography Geophysics. Cosmic physics QC801-809 |
description |
Abstract Radio‐echo sounding (RES) shows large‐scale englacial stratigraphic folds are ubiquitous in Greenland's ice sheet. However, there is no consensus yet on how these folds form. Here, we use the full‐Stokes code Underworld2 to simulate ice movements in three‐dimensional convergent flow, mainly considering ice anisotropy due to a crystallographic preferred orientation, vertical viscosity and density gradients in ice layers, and bedrock topography. Our simulated folds show complex patterns and are classified into: large‐scale folds (>100 m amplitude), small‐scale folds (<<100 m) and basal‐shear folds. The amplitudes of large‐scale folds tend to be at their maximum in the middle of the ice column or just below, in accordance with observations in RES data. We conclude that ice anisotropy amplifies the perturbations in ice layers (mainly due to bedrock topography) into large‐scale folds during flow. Density differences between the warm deep ice and cold ice above may enhance fold amplification. |
format |
Article in Journal/Newspaper |
author |
Yu Zhang Till Sachau Steven Franke Haibin Yang Dian Li Ilka Weikusat Paul D. Bons |
author_facet |
Yu Zhang Till Sachau Steven Franke Haibin Yang Dian Li Ilka Weikusat Paul D. Bons |
author_sort |
Yu Zhang |
title |
Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet |
title_short |
Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet |
title_full |
Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet |
title_fullStr |
Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet |
title_full_unstemmed |
Formation Mechanisms of Large‐Scale Folding in Greenland's Ice Sheet |
title_sort |
formation mechanisms of large‐scale folding in greenland's ice sheet |
publisher |
Wiley |
publishDate |
2024 |
url |
https://doi.org/10.1029/2024GL109492 https://doaj.org/article/55100ba1a1654be090a43728021fea10 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Geophysical Research Letters, Vol 51, Iss 16, Pp n/a-n/a (2024) |
op_relation |
https://doi.org/10.1029/2024GL109492 https://doaj.org/toc/0094-8276 https://doaj.org/toc/1944-8007 1944-8007 0094-8276 doi:10.1029/2024GL109492 https://doaj.org/article/55100ba1a1654be090a43728021fea10 |
op_doi |
https://doi.org/10.1029/2024GL109492 |
container_title |
Geophysical Research Letters |
container_volume |
51 |
container_issue |
16 |
_version_ |
1810449808056385536 |