Chapter 14 Flashcards
Mass wasting
Downslope movement of rock, regolith and soil under the influence of gravity that
doesn’t require a transportation medium such as water, wind or ice.
Landslide
Non-specific term for rapid mass movements of rock or soil
Classification of mass wasting processes (3)
- Type of motion
- Type of material
- Rate of movement
Types of motions (3)
- Falling
- Sliding
- Flowing
Falling
Motion vertically downwards, often through the air.
Sliding
A cohesive unit of rock or soil moves along a clearly defined plane. Caused by weak planes in folded and faulted rocks, glacial erosion, mines.
Slump
Special case of sliding where the material rotates as it moves along a well defined curved
Flowing
Material moves as viscous fluid with turbulent flow.
Types of material in mass movement (2)
Unconsolidated (debris, earth flow) or bedrock (rock slide)
Rates of movement (3)
Creep rate, freeze thaw cycle, solifluction (water saturated over solid layer).
Controls and Triggers of mass wasting (6)
Shear stress, friction, water, vegetation, construction, earthquakes
Oversteepening
A slope that becomes steeper than the angle of repose (25-40°).
Landslide hazard reduction methods (2)
Barriers/protection, and landslide forecasts