Sub-aerial Processes

Question 1

What do sub-aerial processes refer to?

Answer 1

Processes that act on land surfaces, primarily weathering and mass movement.

Question 2

Define weathering.

Answer 2

The breaking down of rock in situ.

Question 3

What are the two main types of weathering?

Answer 3

• Mechanical weathering
• Chemical weathering

Question 4

What causes biological weathering?

Answer 4

Factors like the roots of vegetation, burrowing animals, and nesting birds.

Question 5

What is mechanical weathering?

Answer 5

Physical processes that break down rocks, such as freeze-thaw and wetting/drying.

Question 6

What occurs during salt crystallisation?

Answer 6

Salt applies pressure to cracks in rocks over time.

Question 7

Describe freeze-thaw weathering.

Answer 7

Water freezes in cracks, expands, and applies pressure, breaking the rock.

Question 8

What is chemical weathering?

Answer 8

Weak chemical reactions between water and rock.

Question 9

What is the role of carbonic acid in weathering?

Answer 9

It reacts with calcium carbonate in limestone, leading to weathering.

Question 10

What happens to limestone during carbonation?

Answer 10

It gets weathered and can form complex cave systems.

Question 11

How does weathering affect cliffs?

Answer 11

It weakens cliffs, speeding up erosion rates.

Question 12

What is mass movement?

Answer 12

The movement of material downslope under the influence of gravity.

Question 13

What are the two types of mass movement?

Answer 13

• Rapid events (e.g., landslides, rockfalls)
• Slow processes (e.g., soil creep)

Question 14

What is a common type of mass movement at coasts?

Answer 14

Slumps.

Question 15

What causes slumps?

Answer 15

A combination of marine erosion and rainfall infiltration into slopes.

Question 16

What creates a slip plane in slumping?

Answer 16

Rainwater infiltrates porous material and reaches saturated material above.

Question 17

Fill in the blank: The weakening of cliffs due to weathering leads to _____ rates of erosion.

Answer 17

increased

Question 18

What are the two main types of landforms?

Answer 18

Erosional landforms and depositional landforms

Examples include cliffs, stacks, bars (erosional) and beaches, spits (depositional)

Question 19

What factors influence landforms apart from erosion and deposition?

Answer 19

The relationship between marine erosion and the sub-aerial processes of weathering and mass movement

Weathering includes both physical and chemical processes

Question 20

What are ‘sub-aerial processes’?

Answer 20

Weathering and mass movement, which work together to remove material from the earth’s surface

Question 21

What did Louis Peltier create in 1950?

Answer 21

A diagram showing how temperature and rainfall determine the type of weathering

Physical weathering occurs where rainfall and temperature are low; chemical weathering occurs where rainfall and temperatures are high; freeze weathering occurs where rainfall is low and temperature is high.

Question 22

What is mass movement?

Answer 22

Downslope movement of material under gravity

Influenced by climate, topography, vegetation, and the material itself.

Question 23

What makes the White Cliffs of Dover susceptible to mass movement?

Answer 23

The presence of soft chalk and heavy rainfall increases the likelihood of failure

Over time, saturation due to rainfall can lead to slumping.

Question 24

What led to a large slumping event in Dorset?

Answer 24

Porous sandstone absorbed rainwater, making it heavier

The impermeable layer of Eype clay at the base acted as a sliding plane.

Question 25

How can sub-aerial processes affect the characteristics of cliff profiles?

Answer 25

The presence of a beach at the base of a cliff can protect against erosion ## Footnote Beaches can absorb wave energy and reduce the impact on cliffs.

Question 26

What type of weathering is characterized by the physical breakdown of rocks?

Answer 26

Mechanical weathering ## Footnote Mechanical weathering involves processes like freeze-thaw and exfoliation.

Question 27

Which weathering process involves the dissolution of minerals in rocks by acidic water?

Answer 27

Chemical weathering ## Footnote An example of chemical weathering is carbonation.

Question 28

What is the weathering process occurring in Eastern Australia, particularly involving limestone?

Answer 28

Carbonation ## Footnote Carbonation is a significant chemical weathering process affecting limestone.

Question 29

Fill in the blank: The freeze-thaw process involves water getting into _______ in rocks, freezing, and expanding.

Answer 29

cracks

Question 30

What is the term for the weathering process where layers of rock peel away due to temperature changes?

Answer 30

Exfoliation ## Footnote Exfoliation occurs due to repeated heating and cooling of rocks.

Question 31

What type of weathering occurs when pressure is released from rocks?

Answer 31

Pressure release ## Footnote Pressure release can lead to the expansion and fracturing of rocks.

Question 32

Which organisms contribute to biological weathering by bringing rock particles to the surface?

Answer 32

Burrowing animals ## Footnote Burrowing animals and vertebrates can significantly impact rock weathering.

Question 33

Fill in the blank: Root action in weathering refers to _______ growing down into the soil, affecting the rock.

Answer 33

plant roots

Question 34

What is the primary type of weathering occurring in Northern Greenland?

Answer 34

Mechanical weathering ## Footnote The colder climate in Northern Greenland affects the type of weathering.

Question 35

True or False: Chemical weathering can occur when water interacts with minerals in rocks.

Answer 35

True