5 Kinds of Downward Movement of Soil or Rock

We’re going to take a look at five kinds of downward movement of soil or rock that can occur. First is the avalanche. This is a large mass of snow, ice, soil, or rock, or a mixture of some of those materials, that is falling, sliding, or flowing very rapidly under the force of gravity.

I’m sure you’re somewhat familiar with avalanches, but usually we think of an avalanche just pertaining to snow, but it could be with soil, or rock, or a combination of any of those. Then there’s a fall which is the free-falling or quick movement of a detached segment of bedrock of any size from a cliff or other very steep outcrop or slope, so this is pretty self-explanatory.

Then there’s a rotational slide or slump. This is a slide in which the slip service of failure closely follows the arc of a circle. The slip surface is the contact point when things are about to get loose, basically, it’s the area that is losing friction, and so that’s where the problem is going to occur, that’s where the failure is going to occur, and then something is going to be let loose to start sliding away.

The slip surface of failure in a rotational slide or slump usually follows the arc of a circle, and generally the slide is going to be of homogeneous earth or clay. Then there’s topple, which is an overturning slope movement. This is with a turning point below the center of gravity of the falling unit, so say here that this is the top of a mountain, there’s a rock right here and then it topples, so it just falls from right here, it goes over like this, that would be an example of a topple.

Then there’s a translational slide. This is a landslide displacement in which the components have not rotated relative to one another. Say here that I had a slope here and then I had a rock, and then it just slid down like this. That would be a translational slide.

Everything is still kind of in the same place relative to one another within the slide and all the components here are still in the same spot relative to each other, but they’re now in a different location because they have gone through this slide. That’s a look at some downward movement of soil or rock.