How cold glaciers in the summit region of the Alps may add to polar glaciological research
The non-temperated glacier saddle Colle Gnifetti (Monte Rosa summit range, 4500m asl) offers polar properties regarding englacial temperature and accumulation rate, but differs greatly from polar areas through its strong horizontal gradients of almost all glaciological parameters. Accordingly, this...
| Main Authors: | , , , , , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2010
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/23032/ https://hdl.handle.net/10013/epic.35823 |
| Summary: | The non-temperated glacier saddle Colle Gnifetti (Monte Rosa summit range, 4500m asl) offers polar properties regarding englacial temperature and accumulation rate, but differs greatly from polar areas through its strong horizontal gradients of almost all glaciological parameters. Accordingly, this well characterized glacier constitutes an ideal target for pilot-studies dedicated to innovative polar research attempts. In this context, the LIMPICS project ("linking micro-physical properties to macro features in ice sheets with geophysical techniques") currently deploys instruments on the Colle Gnifetti drilling site, among others, for combining seismic pilot studies with routine ground-penetrating radar (GPR) soundings. Here we report on our attempt linking GPR reflectors to the stratigraphical information on impurity and physical properties obtained from our dense ice core array made up by four down-to-bedrock cores. By evaluating clear reflector signals confined to the upper (firn) section we were able to successfully link the ice core quartet by GPR horizon series allowing for mapping dated isochrones over the last 100 years. Thereby, we obtained an independent consistency assessment of the core chronologies and a detailed picture on the 3D accumulation distribution greatly improving the interpretation of the ice core derived isotope temperature record. Finally, we briefly outline our concept for investigating the origin of GPR reflectors deploying dielectrical and chemical ice core data. Supported by a relatively simple glacier flow model this attempt is eventually aimed at deriving the areal extension of the punctual ice core information (a challenge we meet on the large scale polar ice sheets as well). |
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