Sea-level and solid-Earth feedbacks on ice-sheet dynamics
Ice sheets fundamentally contribute to the climate system by exchanging freshwater with the oceans and influencing the Earth's radiative balance via their surface albedo. On the other hand, changing climatic conditions (precipitation, air and ocean temperature) as well as geothermal heat fluxes...
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ftfuberlin:oai:refubium.fu-berlin.de:fub188/8001 2023-05-15T13:53:47+02:00 Sea-level and solid-Earth feedbacks on ice-sheet dynamics Rückwirkungen von Meerespiegel und fester Erde auf die Dynamik von Eisschilden Konrad, Hannes m Prof. Dr. Maik Thomas Prof. Dr. Giorgio Spada 2015 VIII, 176 S. application/pdf https://refubium.fu-berlin.de/handle/fub188/8001 https://doi.org/10.17169/refubium-12200 https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000099901-5 eng eng https://refubium.fu-berlin.de/handle/fub188/8001 http://dx.doi.org/10.17169/refubium-12200 urn:nbn:de:kobv:188-fudissthesis000000099901-5 http://www.fu-berlin.de/sites/refubium/rechtliches/Nutzungsbedingungen ice dynamics glacial-isostatic adjustment sea level Antarctic Ice Sheet ddc:500 ddc:550 doc-type:doctoralThesis 2015 ftfuberlin https://doi.org/10.17169/refubium-12200 2022-05-15T20:45:55Z Ice sheets fundamentally contribute to the climate system by exchanging freshwater with the oceans and influencing the Earth's radiative balance via their surface albedo. On the other hand, changing climatic conditions (precipitation, air and ocean temperature) as well as geothermal heat fluxes control the advance and retreat of ice sheets during glacial cycles. With the changing ice and ocean load on the Earth's surface, their evolution forces the redistribution of mantle material in the Earth's interior and causes changes of the gravity field and the displacement of the surface, both leading to sea- level change. The gravitational and deformational response depends on the viscoelastic structure of the solid Earth, which in turn has an effect on the dynamic evolution of the ice sheets. In this thesis, a coupled model for ice and solid-Earth dynamics is realized, consistently accounting for surface loading of the Earth by redistribution of ice and ocean masses. It incorporates all primary feedbacks of viscoelastic deformation and gravitationally consistent sea level on the evolution of the modeled ice sheets. In idealized scenarios, it is found that the feedback mechanisms are most important at the boundary between grounded ice and oceans. This feedback is shown to be not adequately accounted for in an approximative representation of the solid-Earth deformation, commonly used in ice-sheet modeling. A possible future collapse of the West Antarctic Ice Sheet (WAIS) in a warming climate including rising sea levels is found to be prevented or delayed by soft viscoelastic Earth structures (i.e. featuring a thin lithosphere and a low-viscous asthenosphere), corresponding to the West Antarctic rift system. It is found that the iterative adjustment of the paleo bathymetry, necessary to match present-day observation of the bathymetry, as well as the ongoing relaxation imply shallower ambient ocean depths in Antarctica for stiffer Earth structures (i.e. featuring a thick lithosphere and a high-viscous mantle) during the ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Eisschild* Ice Sheet Freie Universität Berlin: Refubium (FU Berlin) Antarctic West Antarctic Ice Sheet |
institution |
Open Polar |
collection |
Freie Universität Berlin: Refubium (FU Berlin) |
op_collection_id |
ftfuberlin |
language |
English |
topic |
ice dynamics glacial-isostatic adjustment sea level Antarctic Ice Sheet ddc:500 ddc:550 |
spellingShingle |
ice dynamics glacial-isostatic adjustment sea level Antarctic Ice Sheet ddc:500 ddc:550 Konrad, Hannes Sea-level and solid-Earth feedbacks on ice-sheet dynamics |
topic_facet |
ice dynamics glacial-isostatic adjustment sea level Antarctic Ice Sheet ddc:500 ddc:550 |
description |
Ice sheets fundamentally contribute to the climate system by exchanging freshwater with the oceans and influencing the Earth's radiative balance via their surface albedo. On the other hand, changing climatic conditions (precipitation, air and ocean temperature) as well as geothermal heat fluxes control the advance and retreat of ice sheets during glacial cycles. With the changing ice and ocean load on the Earth's surface, their evolution forces the redistribution of mantle material in the Earth's interior and causes changes of the gravity field and the displacement of the surface, both leading to sea- level change. The gravitational and deformational response depends on the viscoelastic structure of the solid Earth, which in turn has an effect on the dynamic evolution of the ice sheets. In this thesis, a coupled model for ice and solid-Earth dynamics is realized, consistently accounting for surface loading of the Earth by redistribution of ice and ocean masses. It incorporates all primary feedbacks of viscoelastic deformation and gravitationally consistent sea level on the evolution of the modeled ice sheets. In idealized scenarios, it is found that the feedback mechanisms are most important at the boundary between grounded ice and oceans. This feedback is shown to be not adequately accounted for in an approximative representation of the solid-Earth deformation, commonly used in ice-sheet modeling. A possible future collapse of the West Antarctic Ice Sheet (WAIS) in a warming climate including rising sea levels is found to be prevented or delayed by soft viscoelastic Earth structures (i.e. featuring a thin lithosphere and a low-viscous asthenosphere), corresponding to the West Antarctic rift system. It is found that the iterative adjustment of the paleo bathymetry, necessary to match present-day observation of the bathymetry, as well as the ongoing relaxation imply shallower ambient ocean depths in Antarctica for stiffer Earth structures (i.e. featuring a thick lithosphere and a high-viscous mantle) during the ... |
author2 |
m Prof. Dr. Maik Thomas Prof. Dr. Giorgio Spada |
format |
Doctoral or Postdoctoral Thesis |
author |
Konrad, Hannes |
author_facet |
Konrad, Hannes |
author_sort |
Konrad, Hannes |
title |
Sea-level and solid-Earth feedbacks on ice-sheet dynamics |
title_short |
Sea-level and solid-Earth feedbacks on ice-sheet dynamics |
title_full |
Sea-level and solid-Earth feedbacks on ice-sheet dynamics |
title_fullStr |
Sea-level and solid-Earth feedbacks on ice-sheet dynamics |
title_full_unstemmed |
Sea-level and solid-Earth feedbacks on ice-sheet dynamics |
title_sort |
sea-level and solid-earth feedbacks on ice-sheet dynamics |
publishDate |
2015 |
url |
https://refubium.fu-berlin.de/handle/fub188/8001 https://doi.org/10.17169/refubium-12200 https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000099901-5 |
geographic |
Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Eisschild* Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Eisschild* Ice Sheet |
op_relation |
https://refubium.fu-berlin.de/handle/fub188/8001 http://dx.doi.org/10.17169/refubium-12200 urn:nbn:de:kobv:188-fudissthesis000000099901-5 |
op_rights |
http://www.fu-berlin.de/sites/refubium/rechtliches/Nutzungsbedingungen |
op_doi |
https://doi.org/10.17169/refubium-12200 |
_version_ |
1766259230586699776 |