Downslope displacement rates of ploughing boulders in a mid-alpine environment: Finse, southern Norway

Annual and seasonal displacements of ploughing boulders were investigated a t Finse, southern Norway, by traditional surveying and differential carrier -phase global positioning system measurements. Annual displacement rates we re mainly below 10 mm/year, although one particular season showed rates of 26 mm/year on average. There was a tendency for larger boulders to travel f a tcr. Seasonal displacements were restricted to the annual freeze-thaw cyc le. The frost heave seems to have a significant horizontal component, which does not necessarily point in the downslope direction. Thus, the concept o f frost creep is not applicable to the investigated ploughing boulders, On the other hand, due to tilting of the boulders, a momentum may, be gained d uring thaw consolidation that could induce downslope displacements. Such a process will work together with gelifluction.