Landslides and Slumps

1
Landslides and Slumps

• By James Morrison, Only James.

2
Type of Mass Movement Landslides and Slumps
Earliest landslide blocks are hummocky because of
glacial erosion and deposition
Concave sliding surface
Large sections of rock and soil break away and
move quickly down-slope as a unit
Key Downward slumping of
heavy basalt rock
3
Processes

• A landslide is the movement of large quantities
  of rock and/ or earth.
• Landslides are a form of rotational sliding
  which is when a mass of rock slumps along a
  curved plane. This causes the land to break away
  and move downhill as a unit
• This process is very fast.

4
Conditions

• Material involved-
• Soft rock Clay
• Hard rock Sandstone
• Soft material such as clay overlies a harder
  substance such as sandstone.
• Weather conditions-
• Surface soil is saturated after prolonged heavy
  rain which lubricates the rock
• Slopes are undercut because of river or sea
  erosion
• Rock becomes weaker and unsupported.

5
Conditions Continued

• Vegetation-
• Prevented by vegetation as the roots as the roots
  bind the soil.
• Vegetation also protects the soil from heavy rain
  
• Movement-
• The movement is helped by gravity and this
  process happens quickly

6
(No Transcript)