In this paper we use the entire longitudinal (GPR)profile of the Von Postbreen polythermal glacier, acquired in the Tempelfjorden region of the Svalbard Islands to link a peculiar electromagnetic anomalous zone (AZ) to the glacial thermal behaviour possibly influenced by the bedrock shape on which the glacier is lying and by the environmental thermal parameters. We used PoLIM tool, a 2D higher-order thermo-mechanical flowband modelling algorithm trying to explain the occurrences of the AZ and the other EM facies imaged by the GPR. We discovered that the AZ corresponds to a zone where the internal Von Postbreen temperature ranges between −2 °C/ −4 °C and that the Cold/Temperate-ice transition Zone on GPR data has a good correspondence with the 0°C modeled value above a bedrock uplift and with the −2°C value in the central part of the glacier, while a mismatch occurs only close to the front. The findings of this research should be validated by applying the same approach to other glaciers at different altitudes, latitudes and with different geological background, however the obtained results seem to suggest that there is a strong and distinct correlation between GPR EM facies and thermal behaviour of polythermal glaciers.
Polythermal Glaciers: a Link between GPR EM Facies and Glacial Thermal Modeling
Gutgesell, P.
;Forte, E.
2024-01-01
Abstract
In this paper we use the entire longitudinal (GPR)profile of the Von Postbreen polythermal glacier, acquired in the Tempelfjorden region of the Svalbard Islands to link a peculiar electromagnetic anomalous zone (AZ) to the glacial thermal behaviour possibly influenced by the bedrock shape on which the glacier is lying and by the environmental thermal parameters. We used PoLIM tool, a 2D higher-order thermo-mechanical flowband modelling algorithm trying to explain the occurrences of the AZ and the other EM facies imaged by the GPR. We discovered that the AZ corresponds to a zone where the internal Von Postbreen temperature ranges between −2 °C/ −4 °C and that the Cold/Temperate-ice transition Zone on GPR data has a good correspondence with the 0°C modeled value above a bedrock uplift and with the −2°C value in the central part of the glacier, while a mismatch occurs only close to the front. The findings of this research should be validated by applying the same approach to other glaciers at different altitudes, latitudes and with different geological background, however the obtained results seem to suggest that there is a strong and distinct correlation between GPR EM facies and thermal behaviour of polythermal glaciers.Pubblicazioni consigliate
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