Depending on where you live, you may have observed a downslope displaement of trees, fences, or utility poles. This slow displacement is the result of creep, an extremely slow movement of regolith, soil, and rock under the influence of gravity. Creep is the least spectacular of all mass movements. However, its continuity of operation and its widespread action over Earth make it the most important mass movement process in terms of the total volume of material moved downslope each year. Abnorally high rates of creep may indicate that a potentially deep failure is imminent.
Creep acceleration is a mass movement indicator.
The downslope movement of water-saturated regolith is called solifluction. Movement rates can be faster than creep and may attain a few centimeters per year. Solifluction may occur in any climate in which regolith becomes satruated with water. However, it is most common in cold climates where the upper part of the regolith freezes and thaws periodically. Many cold areas are underlain by permanently frozen ground called permafrost .