Soil creep is the slowest type of mass movement and occurs on gentle slopes. Movement can be as slow as 1 cm per year, which means it can take a long time for the effect to be noticeable. Soil creep becomes visible on the landscape through its impact on walls, roads, trees and houses. Terracettes, also known as soil ripples, can be seen on the land.
House with sagging foundations
and cracked walls Curving tree trunk 3. The impact of soil creep
Cracks appearing on the road parallel to the slope
telephone poles
Soil creep zone Intact bedrock
Soil builds up behind wall and puts pressure on it, causing collapse
Working with others
Study the photographs shown here. Then discuss with the person next to you what evidence you can see that soil creep is happening in these areas. Share your thoughts with the class.
A B
With the aid of a diagram, explain the process of soil creep as shown in figure 3 and the impact it has on the landscape.
Tilted
Mudflow
Mudflows occur when the soil and regolith become saturated with water, usually after heavy rainfall. They mix together to form mud, which then moves rapidly downslope. Mudflows are the fastest type of mass movement, with speeds of up to 100 km per hour.