Deep-seated creep of massive ground ice, Tuktoyaktuk, NWT, Canada

A study of the in situ creep deformation of massive ground ice has been carried out at a field site near the village of Tuktoyaktuk, NWT. Cumulative surface displacements, accounted for by creep deformation to a depth of 25 m, vary from about 3 mm/a at the upslope site to 4 mm/a at the downslope site. While net displacements on a year to year basis were downslope, the creep pattern at both sites displays a quasi-sinusoidal fluctuation, with significant seasonal upslope movement during the late winter and early summer. This fluctuation is thought to be due to the effects of thermal contraction.