Not all mass movement occurs rapidly. Mass movement can also occur so slowly that it is not perceptible to the human eye. Examples of this kind of slow mass movement include:

• Creep: The slow, imperceptible movement of soil down an incline is known as creep. Creep is very common in sloped areas that experience frequent freezing and thawing. The rapid freezing and thawing produces lubricating layers that over time can result in a slow slide of the upper layers of soil. Creep is the slowest of all types of mass movement.


Solifluction in the ground at Seward Peninsula, Alaska.
• Solifluction: Solifluction is a type of slow mass movement that occurs in areas that experience permafrost. Permafrost is permanently frozen soil. The upper layers of soil in permafrost areas will thaw in summertime. This muddy, upper layer of soil will slowly side over the hard, permanently frozen soil underneath resulting in a slow mass movement.