Typically, the crest of the slope is slightly convex to angular, the cliff (freeface) is nearly vertical, and a debris slope is present.
And shear strength is a function of cohesion (ability of particles to attract and hold each other together) and internal friction (friction between grains within a material).
Water contributes to resisting forces when sediment pores are partially filled with water.
The driving forces are gravity and the acceleration of the vehicle (if you step on the accelerator), the resisting force is the brake on the vehicle.
The main driving force in most land movements is gravity. Slope angle, climate, slope material, and water contribute to the effect of gravity.
Rockfall (free fall of rock) is an extremely rapid process and occurs without warning. Frost wedging is a process where water enters cracks in rocks, freezes, expands, and breaks the rock apart.
Frost wedging results in a fan-shaped pile of rock fragments at the base of the slope.
Have you ever noticed warning signs posted along roads stating "beware of falling rocks"?
These signs let you know that you are in a hazard zone, an area where rockfall is common!
Three major types of mass wasting are classified by the type of downslope movement.
The types of movement, falls, slides, and flows, will be covered in this module.
Resistant rock and rock from semi-arid regions have similar profiles because in both cases chemical weathering is slow.