Mass movement

Question 1

the nature of mass movement depends on the 4 factors:

Answer 1

• level of cohesion within the sediment
• the height of the slope and slope angle
• grain size within the sediment
• temperature

Question 2

the five types of mass movement are:

Answer 2

• landslides
• rock falls
• mudflows
• rotational slip or slumping
• soil creep

Question 3

landslides occur

Answer 3

on cliffs made from softer rocks or deposited material, which slip as a result of failure within it when lubricated following heavy rainfall

Question 4

rock falls occur

Answer 4

from cliffs undercut by the sea, or on slopes affected by mechanical weathering like frost action

Question 5

muflows are caused by

Answer 5

heavy rainfall which causes large quantities of fine material to flow downhill. this occur where saturated soil sits on top of an impermeable layer, causing the surface layers to slide downhill. on gentler slopes, flows are referred to as solifluction

Question 6

rotational slip or slumping is where

Answer 6

softer material overlies much more resistant rock, making the cliff subject to slumping. with heavy rainfall providing excessive lubrication, whole sections of cliff face move downwards with a slide plane that is concave, producing a rotation movement. slumps are a common feature of the British coast, particularly where glacial deposits form the coastal areas, for example, east Yorkshire and Northfolk

Question 7

soil creep occur

Answer 7

where there is a very slow, almost imperceptible, but continuous movement of individual soil particles downslope. soil moisture is the biggest drive of soil creeps