Fracture-induced softening for large-scale ice dynamics
Floating ice shelves can exert a retentive and hence stabilizing force onto the inland ice sheet of Antarctica. However, this effect has been observed to diminish by the dynamic effects of fracture processes within the protective ice shelves, leading to accelerated ice flow and hence to a sea-level...
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2014
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ftdatacite:10.34657/969 2023-05-15T13:38:20+02:00 Fracture-induced softening for large-scale ice dynamics Albrecht, T. Levermann, A. 2014 application/pdf application/zip https://dx.doi.org/10.34657/969 https://oa.tib.eu/renate/handle/123456789/682 unknown München : European Geopyhsical Union Creative Commons Attribution 3.0 Unported CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 CC-BY Fracture ice flow ice sheet ice shelf ice stream viscous flow 550 CreativeWork article Other 2014 ftdatacite https://doi.org/10.34657/969 2022-03-10T12:43:22Z Floating ice shelves can exert a retentive and hence stabilizing force onto the inland ice sheet of Antarctica. However, this effect has been observed to diminish by the dynamic effects of fracture processes within the protective ice shelves, leading to accelerated ice flow and hence to a sea-level contribution. In order to account for the macroscopic effect of fracture processes on large-scale viscous ice dynamics (i.e., ice-shelf scale) we apply a continuum representation of fractures and related fracture growth into the prognostic Parallel Ice Sheet Model (PISM) and compare the results to observations. To this end we introduce a higher order accuracy advection scheme for the transport of the two-dimensional fracture density across the regular computational grid. Dynamic coupling of fractures and ice flow is attained by a reduction of effective ice viscosity proportional to the inferred fracture density. This formulation implies the possibility of non-linear threshold behavior due to self-amplified fracturing in shear regions triggered by small variations in the fracture-initiation threshold. As a result of prognostic flow simulations, sharp across-flow velocity gradients appear in fracture-weakened regions. These modeled gradients compare well in magnitude and location with those in observed flow patterns. This model framework is in principle expandable to grounded ice streams and provides simple means of investigating climate-induced effects on fracturing (e.g., hydro fracturing) and hence on the ice flow. It further constitutes a physically sound basis for an enhanced fracture-based calving parameterization. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves DataCite Metadata Store (German National Library of Science and Technology) |
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DataCite Metadata Store (German National Library of Science and Technology) |
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Fracture ice flow ice sheet ice shelf ice stream viscous flow 550 |
spellingShingle |
Fracture ice flow ice sheet ice shelf ice stream viscous flow 550 Albrecht, T. Levermann, A. Fracture-induced softening for large-scale ice dynamics |
topic_facet |
Fracture ice flow ice sheet ice shelf ice stream viscous flow 550 |
description |
Floating ice shelves can exert a retentive and hence stabilizing force onto the inland ice sheet of Antarctica. However, this effect has been observed to diminish by the dynamic effects of fracture processes within the protective ice shelves, leading to accelerated ice flow and hence to a sea-level contribution. In order to account for the macroscopic effect of fracture processes on large-scale viscous ice dynamics (i.e., ice-shelf scale) we apply a continuum representation of fractures and related fracture growth into the prognostic Parallel Ice Sheet Model (PISM) and compare the results to observations. To this end we introduce a higher order accuracy advection scheme for the transport of the two-dimensional fracture density across the regular computational grid. Dynamic coupling of fractures and ice flow is attained by a reduction of effective ice viscosity proportional to the inferred fracture density. This formulation implies the possibility of non-linear threshold behavior due to self-amplified fracturing in shear regions triggered by small variations in the fracture-initiation threshold. As a result of prognostic flow simulations, sharp across-flow velocity gradients appear in fracture-weakened regions. These modeled gradients compare well in magnitude and location with those in observed flow patterns. This model framework is in principle expandable to grounded ice streams and provides simple means of investigating climate-induced effects on fracturing (e.g., hydro fracturing) and hence on the ice flow. It further constitutes a physically sound basis for an enhanced fracture-based calving parameterization. |
format |
Article in Journal/Newspaper |
author |
Albrecht, T. Levermann, A. |
author_facet |
Albrecht, T. Levermann, A. |
author_sort |
Albrecht, T. |
title |
Fracture-induced softening for large-scale ice dynamics |
title_short |
Fracture-induced softening for large-scale ice dynamics |
title_full |
Fracture-induced softening for large-scale ice dynamics |
title_fullStr |
Fracture-induced softening for large-scale ice dynamics |
title_full_unstemmed |
Fracture-induced softening for large-scale ice dynamics |
title_sort |
fracture-induced softening for large-scale ice dynamics |
publisher |
München : European Geopyhsical Union |
publishDate |
2014 |
url |
https://dx.doi.org/10.34657/969 https://oa.tib.eu/renate/handle/123456789/682 |
genre |
Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves |
op_rights |
Creative Commons Attribution 3.0 Unported CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.34657/969 |
_version_ |
1766104263206895616 |