Coupled thermo-geophysical inversion for high-latitude permafrost monitoring:assessment of the method and practical considerations
The sedimentary settings of West Greenlandic towns with their fine-grained, often ice-rich marine deposits are of great concern in building and construction projects in Greenland, as they lose volume, strength and bearing capacity upon thaw. Since extensive permafrost thawing over large areas of inh...
| Main Authors: | , , , |
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| Format: | Conference Object |
| Language: | English |
| Published: |
2013
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| Subjects: | |
| Online Access: | https://orbit.dtu.dk/en/publications/2c54c85a-d26a-4464-a0d5-67fd14d79d2e https://backend.orbit.dtu.dk/ws/files/83593890/Tomaskovicova_et_al_2013_Coupled_thermo_geophysical_inversion_for_high_latitude_permafrost_monitoring_assessment_of_the_method_and_practical_consi.pdf |
| Summary: | The sedimentary settings of West Greenlandic towns with their fine-grained, often ice-rich marine deposits are of great concern in building and construction projects in Greenland, as they lose volume, strength and bearing capacity upon thaw. Since extensive permafrost thawing over large areas of inhabited Greenlandic coast has been predicted as a result of climate change, it is of great both technical and economical interest to assess the extent and thermal properties of such formations. Availability of methods able to determine the thermal parameters of permafrost and forecast its reaction to climate evolution is therefore crucial for sustainable infrastructure planning and development in the Arctic. We are developing a model of heat transport for permafrost able to assess the thermal properties of the ground based on calibration by surface geoelectrical measurements and ground surface temperature measurements. The advantages of modeling approach and use of exclusively surface measurements (in comparison with direct measurements on core samples) are smaller environmental impact, cheaper logistics, assessment of permafrost conditions over larger areas and possibility of forecasting of the fate of permafrost by application of climate forcing. In our approach, the heat model simulates temperature distribution in the ground based on ground surface temperature, specified proportions of the ground constituents and their estimated thermal parameters. The calculated temperatures in the specified model layers are governing the phase distribution between unfrozen water and ice. The changing proportion of unfrozen water content as function of temperature is the main parameter driving the evolution of electrical properties of the ground. We use a forward modeling scheme to calculate the apparent resistivity distribution of such a ground as if collected from a surface geoelectrical array. The calculated resistivity profile is compared to actual field measurements and a difference between the synthetic and the measured ... |
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