What is the most common form of mass movement of soil?

Soil creep is recognized as the most common form of mass movement of soil due to its slow and continuous nature. It occurs when soil moves downward on a slope under the influence of gravity, albeit at a very gradual pace – often measured in millimeters per year. This process is particularly prevalent in places where factors such as moisture, soil saturation, and freeze-thaw cycles facilitate the slow movement of soil particles down a slope.

Soil creep can be influenced by vegetation cover, the type of soil, and slope angle, which makes it a widespread phenomenon in various landscapes, especially in hilly or mountainous areas. Over time, soil creep can significantly modify the landscape, leading to characteristic landforms and affecting agricultural practices.

Other forms of mass movement listed, such as landslides, rockfalls, and debris flows, typically occur more rapidly and under specific conditions like heavy rainfall or seismic activity. While these can be more dramatic events, they are not as common as soil creep, which subtly but steadily shapes the terrain.