Lesson 8 Mass Wasting Flashcards
The downslope movement of rock, regolith, and soil under the direct influence of gravity?
Mass Wasting
What is the controlling force of mass wasting?
Gravity
Factors (4) that influence or trigger downslope movements?
Saturation of the material with water
Oversteepening of slopes beyond the angle of repose
Removal of anchoring vegetation
Ground vibrations from earthquakes.
The steepest angle at which a sloping surface formed of a particular loose material is stable?
angle of repose
Are oversteepened slopes stable?
no
What is it when unconsolidated granular particles assume a stable slope?
the angle of repose
What changes depending on the various materials?
stable slope angle
What two things does saturation of the material with water do to the material?
Destroys particle cohesion
Water adds weight
In the evolution of most landforms, what step does mass wasting follow?
weathering
What is produced from the combined effect of mass wasting and erosion by running water?
stream valleys
What describes and classifies the various processes of mass wasting?
the type of material involved
the kind of motion
the rate of the movement
What are 4 common materials involved in mass wasting?
Debris
Mud
Earth
Rock
What are the three movements that can occur with mass wasting?
fall
slide
slow
What mass wasting movement involves a free-fall of pieces?
fall
What mass wasting movement involves material that moves along a well-defined surface?
slide
What mass wasting movement involves material that moves as a viscous fluid?
slow
What are the two types of movement?
slow
fast
Which forms of mass wasting include the more rapid movements?
slump
rockslide
debris flow
earthflow
Which forms of mass wasting include the slow movements?
creep
soliflucation
Mass wasting with blocks of bedrock that move down a slope?
rockslide
Mass wasting with movement along a curved surface
and along oversteepened slopes?
slump
Mass wasting with a flow of debris with water?
Debris flow
Mass wasting often confined to channels?
Debris flow
Mass wasting with in dry areas with heavy rains?
Debris flow
Mass wasting with debris flows composed mostly of volcanic materials on lahars?
Debris flow
the flanks of volcanoes
lahars
What is debris flow also called?
mudflow
Mass wasting that occurs on hillsides in humid regions?
earthflow
a special type of earthflow sometimes associated with earthquakes
liquefaction
Mass wasting where water saturates the soil?
earthflow
Mass wasting associated with liquefaction?
earthflow
Mass wasting with slow movement of soil and regolith downhill?
creep
Mass wasting that causes fences and utility poles to tilt?
creep
Mass wasting in areas underlain by permafrost?
solifluction
Mass wasting where upper (active) soil layer becomes saturated and slowly flows over a frozen surface below?
solifluction
