Final answer:
Water-saturated soil moving downslope slowly is known as soil creep or solifluction, not to be mistaken for rapid movements like landslides. It's a form of mass wasting that causes landscape features like terraces on slopes, differing from erosion, sedimentation, and weathering.
Step-by-step explanation:
The phenomenon where water-saturated soil moves downslope at a slow rate, either a few millimeters or centimeters per day or per year, is known as soil creep or solifluction. This process is a type of mass wasting event that often occurs in regions where there is consistent soil saturation, either from precipitation or from thawing of frost. It differs from rapid movements such as landslides, which can be triggered by factors like heavy rainfall, earthquakes, volcanic eruptions, or overloading slopes with weight, and can cause serious damage to structures. Contrarily, soil creep is a much slower process that can cause features such as terraces on slopes.Solifluction is not to be confused with erosion, which is the process of transporting soil or rock fragments by water, wind, or ice, shaping the landscape over time. It is also distinct from sedimentation, which involves the accumulation or deposition of sediments, and weathering, which is the breakdown of rocks and minerals at the Earth's surface.