Mass Movement

Question 1

What is mass movement?

Answer 1

The downhill movement of material under the influence of gravity

Question 2

What can cause mass movement?

Answer 2

Through flow and runoff caused by heavy rain can make cliffs more unstable and increase the likelihood of mass movement

Question 3

What does mass movement include?

Answer 3

Landslides, slumping and rockfalls

Question 4

What determines the type of mass movement?

Answer 4

Angle of slope (steeper means the faster the movement), amount and type of vegetation, water, type and structure of the rock, human activity, climate

Question 5

Explain soil creep?

Answer 5

Soil expands when it freezes and gets wet or is heated up in the sun, as the soil expands it lifts at a right angle to the slope, when the soil shrinks it falls back down, takes a long time

Question 6

Explain flow?

Answer 6

Occurs on slopes between 5 and 15 degrees with quicker speeds, happens after the soil has become saturated with a flow of water across the surface, the vegetation is flattened and carries away with the soil

Question 7

Explain slide:

Answer 7

Movement of material which remains together until hitting the bottom of a slope, the material shifts in a straight line

Question 8

Explain rock fall:

Answer 8

Slopes are steep and movement is rapid, when material breaks off and falls down the slope, extreme weathering like freeze thaw can loosen rock that becomes unstable and collapse, rainfall (too much) can soften the surface leading to the collapse of the slope, earthquakes can dislodge unstable rocks, hot weather can dry our soil causing it to shrink, allowing rocks to fall

Question 9

Explain slump:

Answer 9

Weaker rock type (eg. Clay) that becomes heavy and saturated, known as rotational slip, involves a large area of land moving down the slope in 1 piece, because of the way it slumps it leaves behind a curved indented face, material shifts with a rotation