Sub-aerial Weathering

Question 1

What are the three types of weathering?

Answer 1

Mechanical/ physical
Biological
Chemical

Question 2

What type of weathering is freeze-thaw?

Answer 2

Physical

Question 3

What type of weathering is carbonation?

Answer 3

Chemical

Question 4

What type of weathering is solution?

Answer 4

Chemical

Question 5

What type of weathering is hydration?

Answer 5

Chemical

Question 6

What type of weathering is pressure release?

Answer 6

Physical

Question 7

What type of weathering is hydrolysis?

Answer 7

Chemical

Question 8

What type of weathering is oxidation?

Answer 8

Chemical

Question 9

What does physical weathering depend on?

Answer 9

It depends on the nature of the climate.

Question 10

What is chemical weathering?

Answer 10

This is where chemical processes break down the rocks.

Question 11

When does chemical weathering occur?

Answer 11

This occurs when rocks are exposed to air and moisture.

Question 12

What is biological weathering?

Answer 12

This involves processes that lead to the break down of rocks by vegetation and coastal organisms.

Question 13

What is pressure release?

Answer 13

This is where geomorphological processes remove overlying material from the rock.

Question 14

What geomorphological processes cause pressure release?

Answer 14

Weathering, mass movement and erosion.

Question 15

What is freeze-thaw?

Answer 15

This is where water enters cracks in the rocks and then freezes. When water freezes it expands and therefore exerts pressure on the rock. The process repeats causing the crack to widen and then pieces of rock to break off.

Question 16

What is solution?

Answer 16

This is where water dissolves rocks.

Question 17

What is oxidation?

Answer 17

This is where oxygen that is dissolved in the water reacts with minerals in the rocks to form oxides and hydroxides which causes the rock to disintegrate.

Question 18

In what type of rock is oxidation most likely to occur?

Answer 18

Oxidation mainly affects ferrous, iron rich rocks.

Question 19

What is hydration?

Answer 19

This is where water is added to the rock, causing it to expand by creating stress.

Question 20

What can hydration cause?

Answer 20

It can cause rocks to disintegrate or cracks and joints to widen.

Question 21

What is hydrolysis?

Answer 21

This is where mildly acidic water reacts or combines with minerals in the rock to create clays and dissolvable salts which degrades the rock. The clays and salts are likely to be weaker than the parent rock.

Question 22

What is carbonation?

Answer 22

This occurs when CO2 is dissolved in rainwater to create a weak carbonic acid which reacts with calcium carbonate rocks to make calcium bicarbonate which dissolves easily in water.

Question 23

Give two examples of calcium carbonate rocks.

Answer 23

Limestone an chalk.

Question 24

Where is carbonation most effective?

Answer 24

It is mot effective in areas with cool temperatures.

Question 25

What is acid rain?

Answer 25

This is where slightly acidic rainwater caused when water mixes with certain compounds, dissolves rock.

Question 26

What type of weathering is acid rain?

Answer 26

Chemical

Question 27

What does the nature of mass movement depend on?

Answer 27

It depends on the level of cohesion within the sediment. The height and angle of the slope. Grain size within the sediment. Temperature and level of saturation.

Question 28

What can mass movement either be?

Answer 28

It can either be rapid sudden failures of the slope or the effect of a process that has been ongoing for sometime.

Question 29

What are rockfalls?

Answer 29

These occur from cliffs that have been undercut by the sea or on slopes affected by mechanical weathering.

Question 30

What are landslides?

Answer 30

This occurs on cliffs made from soft rock or deposited material which slips as a result of a failure in the rock when lubricated.

Question 31

What are landslides usually caused by?

Answer 31

Heavy rainfall.

Question 32

What is rotational slip or slumping?

Answer 32

Excessive lubrication causes whole sections of the cliff face to move downwards with a concave side plane which creates a rotational movement.

Question 33

What causes rotational slip or slumping?

Answer 33

This occurs when softer material overlies harder, more resistant material.

Question 34

What are mudflows?

Answer 34

This occurs when heavy rain causes large quantities of material to flow downhill.

Question 35

What causes mudflows?

Answer 35

When soil becomes saturated, excess water cannot percolate deeper into the ground, the surface layers become very fluid and flow downhill.

Question 36

What are mudflows referred to as on gentle slopes?

Answer 36

Solifluction

Question 37

What is soil creep?

Answer 37

This is the very slow but continuous movement of individual soil particles downwards.

Question 38

Is runoff a type of mass movement?

Answer 38

No

Question 39

What is run-off?

Answer 39

This is water that runs across the land surface. Sometimes it can take large quantities of load with it.