Types Of Mass Wasting Flashcards
Name the 7 types of mass wasting
Scree, soil creep, landslide, mudflow, slump, avalanche, soil solution
What are the natural causes of mass wasting?
Freezing and thawing
When water seeps into soil, the soil expands and becomes heavier. Adding the weight of water, in the form of rain or snow, may be enough to trigger a form of mass wasting.
During winter months, freezing and thawing action expands and contracts the soil > mass wasting
What are human-made causes of mass wasting?
Deforestation, clear cutting, urbanization affecting natural drainage patterns
Removing of trees leaves a mountain slope with little vegetation to prevent mass wasting.
What is mass wasting?
Downhill movement of weathered rock particles and soil material caused only by the force of gravity
Basically, weathered rock and soil fall down
Scree
Occurs on very steep, rocky slopes where weathered rock fragments are broken off by frost shatter and fall to the base of the cliff.
The pile formed at the base of the cliff is known as a scree or talus
Soil Creep
The slow, but steady downhill movement of soil
Results in leaning trees, telephone poles, and fences on hillsides, causing much property damage.
The vegetation is stretched and it produces terracites
Landslide
Rapid movement of soil down a slope (occurs on slopes that are not steep enough for a scree formation to take place)
Well defined zone/plane of sliding, material moves as a cohesive mass
Can be triggered by: heavy rain, a river undercutting the slope, construction, or the removal of vegetation
Mudflow
When soil on a slope absorbs too much water and the soil begins to flow downhill like a liquid.
(Happens most often in sandy soils where the absorbed water can flow)
((Slopes with high clay content turns the flow into a slide or a slump))
Slump
A section or slab of land breaks away from the rest of the slope and slips a short distance downhill (looks like stairs!)
When a slump occurs, the top layer of soil and the vegetation remain intact
Avalanche
A mass of snow and/or ice breaks away and slides down a mountain slope
Can be triggered by: wind, earthquakes, rising temperatures, heavy rain or snowfall, or skiers
Soil Solution
Invisible type of mass wasting that occurs when water carries away dissolved soil materials.
Occurs on the surface of the earth and under the soil as water seeps downwards
(Transport occurs horizontally and vertically)
Rockfall (optional, idk if it’s important)
Free fall of soil and rock (ROCK FALL. FALLING ROCK.)
What are some methods of stabilizing slopes?
**Vegetation: roots of trees, plants, and grass anchor the soil and protect it from being washed away by heavy rains
Long bolts: fastened into rock to keep slope intact
Concrete spray: binds slope together
Wire mesh netting: minimizes danger from falling rocks (catches)
Pipe inserts: drain away excess water so the slope does not become saturated
Terracing: reduce the angle of the slope (gentle slopes are more stable)
Retaining walls: stop falling rock and minimize debris reaching the road
Snow sheds: areas of heavy snowfall, allow snow to pass over shed and keep roads clear
Tunnels: constructed in mountainous where gradients are too great for slope stabilization
