Sensitivity of a spatially-varying Elastic Lithosphere-Relaxed Asthenosphere (ELRA) isostatic model of the Antarctic ice sheet
On glacial-interglacial time scales, isostatic effects of ice sheet volume changes may have a large impact on timingand magnitude of retreating and advancing ice through grounding-line migration. A common isostatic model usedin ice-flow modelling is the Elastic Lithosphere-Relaxed Asthenosphere (ELR...
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| Format: | Conference Object |
| Language: | English |
| Published: |
2018
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| Online Access: | http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/283593 https://dipot.ulb.ac.be/dspace/bitstream/2013/283593/3/Poster_UNITER_2018_vcoulon.pdf |
| Summary: | On glacial-interglacial time scales, isostatic effects of ice sheet volume changes may have a large impact on timingand magnitude of retreating and advancing ice through grounding-line migration. A common isostatic model usedin ice-flow modelling is the Elastic Lithosphere-Relaxed Asthenosphere (ELRA) model. It considers an elasticlithosphere, defined by a given effective lithosphere thickness and a relaxation equation for asthenospheric responsewith a characteristic time scale as a function of asthenosphere viscosity. However, effective lithosphere thicknessin Antarctica ranges from tens (West-Antarctica) to hundreds of meters (East Antarctica), leading to a flexuralrigidity that varies spatially across several orders of magnitude. Furthermore, recent studies also point out to alarge spatial variability in asthenosphere viscosity. Here, we explore in a sensitivity analysis both spatially uniformand spatially varying values of flexural rigidity and asthenosphere viscosity applied to a model of the Antarcticice sheet, forced by background temperature and sea-level changes over the last 40,000 years, thus covering thelast glacial-interglacial transition. Results demonstrate a higher sensitivity for the West Antarctic ice sheet, whereasthenosphere viscosity essentially influences timing and magnitude of grounding-line retreat during the glacialinterglacialtransition. info:eu-repo/semantics/published |
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