1. Solifluction

• Solifluction is a form of creep that occurs in cold climates or high altitudes where masses of saturated rock waste move downslope.
• Generally, the bulk of the moving mass consists of fine debris but blocks of appreciable size also may be moved.
• Saturation is brought about by rain or melting snow. Moreover, in periglacial regions, water commonly cannot drain into the ground since it is frozen permanently.
• Solifluction differs from mudflow in that it moves much more slowly, the movement is continuous and it occurs over the whole slope. See Figure 5.1

2. Soil Creep

• Creep refers to the slow downslope movement of superficial rock or soil debris, which usually is imperceptible except by observations of long duration.
• It is a more or less continuous process that is distinctly a surface phenomenon and occurs on slopes with gradients somewhat in excess of the angle of repose of the material involved.
• Similarly to landslip, the principal cause of creep is gravity, although it may be influenced by seasonal changes in temperature, and by swelling and shrinkage in surface rocks.
• Evidence of soil creep may be found on many soil-covered slopes. See Figure 5.2