Mass Wasting

When mass wasting by flow occurs so slowly that it cannot be observed, it is called creep. Most vegetated slopes in humid climates are subject to soil creep, and there are many indicators that it occurs. Poles and fence posts often tip away from a slope a few years after they are emplaced. Trees growing on a slope usually have trunks with sharp curves at their bases. Older trees are bent more than younger ones. All this occurs because the upper layers of soil and weathered rock move gradually down the slope while deeper layers remain relatively fixed. This tips inanimate objects such as power poles. It would tip trees, too, except that they grow toward the sun, keeping the trunk growing vertically, and so a bend develops.

This gradual downslope movement requires years to result in significant transport, but because it occurs over a great portion of the surface of the Earth it is responsible for most mass wasting.