GEG 1301 Lecture Notes - Lecture 15: Frost Heaving, Permafrost, Solifluction

• School: University of Ottawa
• Department: Geography
• Course: GEG 1301
• Professor: Denis Lacelle

Document Summary

Water and ice may play a role, but they are not dominant. While creep is typically a slow process, it can be quite rapid under the right conditions. Continuous creep is caused by the deformation of the soil/rock due to its own weight. Typically less than 1 mm per year. Can be faster in permafrost environments (rock glaciers several cm/year) Solifluction: a combination of frost creep and gelifluction (downslope movement of saturated soil), leads to internal deformation. Surface rates ~ 1-5 cm/year, as you get deeper speed decreases. One-sided freezing = concave downslope velocity profile, seasonally frozen ground and discontinuous permafrost. Two-sided freezing = convex downslope velocity profile, continuous permafrost. Can form lobes or sheets (from a few m 10s of m, and rising 0. 5-3 m) Flows: movement incorporating viscous, fluid or plastic motion (high moisture content), typically leaves scars. Earthflow: slowest flow, rarely cause damage, crescent scar, short flow track and bulging lobe.