1. A B
1.What is / has happened in each photo
2. Where might they be taken?
3. What links all 4? C D

2. Key Question: What are the causes of landslides
and why do the impacts on people vary?
1979
1981
Key Words:
Secondary Hazard
Mass Movement
Saturated
Lateral Blast
Think?
What has happened to this mountain?

3. Causes of Landslides Words to use: Stress Gravity Strength
mass movement
stress
down
soil
Causes of Landslides
mass movement
Another name for a landslide is a……………….. ……………………. They are ………………….. slope movements of rock, sediment or…………………………………The force…………………………….. is responsible for all mass movements. They occur when the…………………………. is increased on a slope or when the …………………………………… decreases.
down
soil
gravity
stress
strength
Stress
Gravity
Strength

4. The Effect of Water
Max angle = angle of repose
Internal cohesion

5. 2. Water
Pore water pressure = liquefaction

6. Types of Mass Movement
Flows

7. Pick a minimum of 5 and explain how they cause landslides?
Strength
Stress
Increase in water content of slope
Increase in slope angle
Soft clay soils
Shocks & vibrations like earthquakes
Weathering
Loading the slope with additional weight
Alternating layers of varying rock types/lithology
Undercutting the slope
Burrowing animals
Removal of vegetation
Think carefully is it stress of strength which changes?

8. A B
What type of mass movement is each? C D

9. In your notes write as many facts down about each of the case studies

10. Holbeck Hall Hotel, Scarborough, 1993
Heavy rain
Saturated Ground
Clays

11. Aberfan, South Wales 1966
Spoil Heaps
Built on spring line

12. Mt St Helen’s 1980
Lateral Blast Eruption

13. Karakoram Highway, Pakistan
Highly weathered rock
Steep Sides
Earthquakes common

14. Now explain for each of the 4 why the landslip occurred?
What caused strength to change?
What caused stress to change?
Extension: Thinking about the levels of economic development in each example, put them in order of worst to least effect on people and explain your 1st and 4th choice!