Frost Heave and Creep in the Sør Rondane Mountains, Antarctica

Abstract

Frost heave, slope deformation, and ground temperature have been monitored for 5 yr on ice-free mountains in Antarctica, where only diurnal frost action operates during the midsummer. The monitoring was done at three sites with similar soils but different local climates. Diurnal freeze-thaw cycles result in significant heave (max. 3.4 mm) and downslope movements (max. 1.5 cm yr^–1 at the surface) on some wet slopes subject to both snow flurries and strong insolation. The estimation from the cumulative frost heave measurements indicates that frost creep is most responsible for the movements. The velocity profile, calculated using the values of thaw depth and frost heave, agreed fairly well with the actual profile, demonstrating that subsurface freeze-thaw frequency is the primary control of the profile. However, such activities are insignificant on the most of the mountain slopes owing to little thawing and/or a moisture shortage. Significant frost heave and creep usually take place after the ground achieves water content of > 5% and has thawed deeper than 7 cm.