What are the sub-aerial processes ? Flashcards
1
Q
What is mass movement ?
A
A sub-aerial process, involving the downhill movement of material under the influence of gravity
2
Q
What are the examples of mass movement ?
A
- Soil Creep
- Rotational Slumping
- Rockfalls
- Landslides
- Mudflows
- Runoff
3
Q
What is soil creep ? + What causes it ?
A
- Very slow movement downhill (1 cm/year) of individual soil particles
- Particles dislodged by raindrops or wave splash + typically freeze-thaw or wetting + drying
- Caused by gravity (slopes more than 5 degrees)
4
Q
What is rotational
slumping ? + What causes
it ?
A
- Heavy rain infiltrates unconsolidated soil
- Impermeable soil traps water adding weight
- Undercutting causes collapse on slip plane
5
Q
What is rock fall ? + What causes it ?
A
- Caused by physical weathering
- Weaknesses exposed and can no longer support itself
6
Q
What is landslides ? + What causes it ?
A
- A significant section falls
- Unconsolidated, shales and sandstones
- Sudden
- Usually been lubricated
7
Q
What is mudflows ? + What causes it ?
A
- Excessive amounts of rainfall
- Infiltration can’t take place as soil is saturated
- Fine particles of mud
8
Q
What is runoff ? + What causes it ?
A
- Intense rainfall
- Impermeable surface
- Transports fine material
- Might also be transported by a river
9
Q
What is an example of a landslide/mudflow ?
Give data ?
A
Ischia
- 2022
- At least 12 people died
- 126 mm of rainfall in 6 hours
- Steep slopes
- Deforestation
- Illegal buildings
10
Q
What is talus / scree ?
A
Rock / material left at the bottom of the slope.
