Weathering And Erosion Flashcards
What is Scree/Talus?
Formation of ice within mountain rock slopes, freezes , expands and cracks
What is Soil Creep
It is when damp soil moves very slowly down a slope as the weight of water pushes it forward
Landslide
A Rapid movement of soil down slope . Can occur on slopes that are not steep enough for scree. Direct influence of gravity.
Mud slide and debris flow
Sandy soils absorb water and it tends to flow , causing a fast moving “river” of dirt and debris liquified by water
Slump
A term used for a section or a slab of land that breaks away and slips a short distance down slip. The top layer of soil and vegetation usually untouched.
Rockfalls and Avalanches
A mass of rock or snow breaks away and slides down mountain slope. Triggered by wind, skiers, earthquakes, etc. air temp also affects it
Soliflunction
Very slow movement of saturated soil , related to freeze thaw activity
Difference between Weathering and erosion
Erosion breaks down rock and particles are carried away by wind and water but weathering degrades rock without displacing them.
Difference between physical and chemical weathering
Physical weath. Breaks the rock apart, chemical weath. Changes it’s composition.
4 main types of physical weathering
Frost shatter, plant roots, thermal expansion , exfoliation
Frost shatter
Happens in northern/temperate regions. Water enters cracks in rocks then freezes and expands the rock
Plant roots
As roots grow into cracks they force the rock apart.
Thermal expansion
During the day hot sun heats the rocks and expansion happens . At night rock contracts and some may fall off
Exfoliation
Thin layers of rock peel off the outer surface of the rock face.
Three main types of chemical weathering
Solution : falling rain droplets absorb C02 from atmosphere and mild acid called carbonic acid created
Hydrolysis
Carbonic acid works on minerals called silicates , a new solution is formed as chemicals in rock interact with water
Oxidation
As waters comes into contact with iron oxide , it dissolves and gets carried away. Oxygen dissolved in water can Change into iron oxide
What is Mass wasting ?
Mass wasting is the downhill movement of weathered rock particles/soil material caused by the force of gravity and other factors. Rates affected due to amount of water in weathered material , presence of vegetation , human activities , etc.
Why is vegetation important in stabilizing slopes
Vegetation is important because plants roots anchor the soul and help hold it in place
Causes of Mass wasting
Human interaction with government, like mining destruction and lodging. Rainfall also causes it because it causes soil to expand and become heavier.
How do hot springs form
If water percolates deeply enough into the crust, it comes into contact with hot rocks near mantle and can circulate to the surface to form hot springs.
Why did the frank slide occur ?
- Water(rivers) through running mountain, heavy rain in the spring season, also freeze thaw action because of season weather, gravity and as well as mountain instability.
