Frozen ground conditions in a subarctic mountain environment, Northern Sweden

Abstract

Frozen ground conditions and the geomorphological significance of contemporary permafrost have been assessed in a mountain environment south of Abisko, Sweden, using a combination of different methods including geomorphological mapping, near-surface temperature monitoring and 2D near-surface geophysics. The results confirm the existence of permafrost and related periglacial morphodynamics (e.g. gelifluction) for most of the upper parts of the investigation area (above 1200 m a.s.l.). The middle parts form a transition zone with periglacial morphodynamics related to perennial and seasonal frost (gelifluction/solifluction) in combination with presently inactive periglacial landforms (ca. 1100 to 1200 m a.s.l.). At lower altitudes recent morphodynamics are not related to contemporary permafrost conditions although landforms indicating the former impact of permafrost are present. The permafrost distribution is heterogeneous, showing a strong relationship to the distribution and duration of snow cover and surface textural characteristics. These factors together with the local hydrological conditions also determine the characteristics of the frozen ground. Multiple 2D electrical resistivity imaging surveys pointed to highly variable subsurface resistivity patterns corresponding to different frozen ground characteristics at close distance.