Sammendrag
Soil temperature variation is one of the governing factors of mechanical properties of frozen soils and has a large effect on the stability of soil masses in regions affected by permafrost. The understanding of the thermal regime is critical for planning, designing, constructing, and maintaining infrastructure needed to sustain communities and/or industries in these regions. Detailed studies on the effects of thermal variations based on field data measured in permafrost are limited due to the high cost and high risk associated with field investigations in these remote areas. This study will contribute to bridge the current knowledge gap through an investigation of the thermal regime in permafrost at Pesyakov Island in the Varandey settlement along the Barents Sea coast, in northwest Arctic Russia. Samples were collected and thermistor string was installed at a series of 6 boreholes along a 500 m transect. The transect crosses a coastal barrier island from the beach margin through a dune belt to the laida zone. Continuous measurement of the ground temperature over a period of two years reveals a strong correlation between the surface conditions (air temperature, vegetation, snowfall) and the variation of soil temperature above the permafrost. Numerical modelling of the transect, calibrated with the measured soil temperature, shows important features of the thermal profile, including the existence of frozen soil lenses within unfrozen soil masses and vice versa.