Ch.9 Mass Movement Flashcards
Mass movement
the movement of loose material on the earth’s surface due to gravity
Regolith
loose material, formed by weathering and erosion, made up of soil, gravel and rocks
Gradient
The angle of a slope
Lahars
form when volcanic eruptions which melt snow on volcanic cones, causing huge amounts of water to flow downhill suddenly
Name 4 types of mass movement
- Soil creep
- bog bursts
- mudflows
- landslides
How does soil creep happen
I t occurs as soil moves very slowly down gentle slopes
How do bog bursts happen
They happen when a pear bog becomes completely full of water after heavy rain and causes it to burst and slide downhill
How do mudflows happen
They are Thick rivers of mud and rock that sweep downhill, burying everything in their path
How do landslides happen
When huge amounts of regolith slide downhill at a great speed, destroying everything in their path
Soil creep
- gentle
- dry
- slow
Bog bursts
- Gentle to steep
- wet
- fast
Mudflows
- Gentle to steep
- Wet
- Very rapid
Landslides
- Steep
- Dry
- Rapid
Name 3 effects of mass movement
- death or injury
- polluted water
- migration
What factors influence mass movement
- gradient/slope
- vegetation
- water content
- Human activities
