L3 - Sliding on the edge

Question 1

In what situation do concordant coastlines appear?

Answer 1

When beds/layers of differing rock types get folded into ridges that run parallel to coasts.
Harder rock layers protect soft rock layers before it.

Question 2

In what situation when the hard rock is in front of the soft rock does the soft rock become subject to erosion?

Answer 2

If there is a puncture in the hard rock the soft rock is exposed.

Question 3

What stresses are there on coastlines?

Answer 3

• Slope angle
• Rainwater/saturation
• Vibration
• Cliff erosion
• Earthquakes

Question 4

What affects the strength of a slope On a coastline?

Answer 4

• Lubricant layers (weakens the cliff)
• Vegetation - tree roots (strengthen the cliff). It can also weaken in if the tree roots break the soil apart…
• Soil porosity (weakens the cliff(

Question 5

What can increase the likelihood of landslides?

Answer 5

• Prolonged precipitation causing rock saturation
• Undercutting (excavation of the slope)
• Buildings increase weight and add stresses

Question 6

Give an example of mechanical, chemical and biological weathering.

Answer 6

Mechanical - freeze-thaw weathering
Chemical - acid rain, weakens rocks to break them down
Biological - Plant roots widen cracks in cliff rock, burrowing animals can stress cliffs

Question 7

What are 3 types of mass movement?

Answer 7

Rock falls
Slumping
Sliding

Question 8

Describe and explain what happens during rock falls.

Answer 8

Pieces of rock fall from cliffs that have been weathered or undercut (base of cliff), rock above is not supported and collapses

Question 9

Describe and explain what happens during slumping.

Answer 9

High precipitation
Water seeps through permeable rock, when it meets impermeable rock the saturated permeable rock slumps in a rotational manner.

Question 10

Describe and explain what happens during sliding.

Answer 10

Similar to slumping, material moves across flat surfaces