Evolution of the East Antarctic ice sheet: a numerical study of thermo-mechanical response patterns with changing climate
An efficient numerical ice sheet model, including time dependence and full thermo-mechanical coupling, has been developed to investigatethe thermal regime and overall configuration of a polar ice sheet with respect to changing environmental conditions. From basic sensitivityexperiments, in which a s...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
1988
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| Online Access: | https://epic.awi.de/id/eprint/3659/ https://epic.awi.de/id/eprint/3659/1/Huy1988a.pdf https://hdl.handle.net/10013/epic.14236 https://hdl.handle.net/10013/epic.14236.d001 |
| Summary: | An efficient numerical ice sheet model, including time dependence and full thermo-mechanical coupling, has been developed to investigatethe thermal regime and overall configuration of a polar ice sheet with respect to changing environmental conditions. From basic sensitivityexperiments, in which a schematic East-Antarctic Ice Sheet is forced with a typical glacial-interglacial climatic shift, it is found that (i):themutual interaction of temperature and deformation has a stabilizing effect on its steady state configuration (ii) in the transient mode, thisclimatic transition initially leads to increased ice thickness due to enhanced accumulation, whereafter this trend is reversed due to a warmerbase. Time scales for this reversal are of the order of 103 years in marginal zones and of 104 years in interior parts. (iii): horizontal heatadvection plays a major role in damping possible runaway behaviour due to the dissipation-strain rate feedback, suggesting that creepinstability is a rather unlikely canditate to initiate surging of the East-Antarctic Ice Sheet.The model is then applied to 4 East-Antarctic flowlines. Only the flowline passing through Wilkes Land appears to be vulnerable towidespread basal melting due to enhanced basal warming following a climatic warming. Time-dependent modelling of the Vostokflowline, indicates that the Vostok Station area has risen about 95 m since the beginning of the present interglacial, which is of particularinterest in interpreting the palaeoclimatic signal of the obtained ice core there. |
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