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 .
During warmer parts of the year, the uppermost part of this ground thaws and releases water within the sediment. This soggy mass of soil then can flow downslope over the permafrost beneath. Solifluction creates a topography characterized by curved lobate flows on the surface. Mudflows are common on slopes in semiarid areas, where rare but intense, short-lived rainstorms rapidly convert regolith into a mass of viscous mud and rock that moves downslope at high velocity. Mudflows are a serious geohazard in urbanized dry areas such as in the Los Angeles Basin, where development has spread onto steep mountain fronts.