Unit 1C - Coastal Landscapes in the UK - Weathering, erosion and mass movement

Question 1

Weathering definition?

Answer 1

Breakdown of rocks by physical or chemical changes in situ

Question 2

Erosion definition?

Answer 2

Wearing away and removal of land by rivers, glaciers and wind.

Question 3

Difference between physical/mechanical and chemical weathering?

Answer 3

M - Disintegration of rock without a chemical change, usually associated with extremes of climate
C - Decomposition of rocks caused by a chemical reaction within rock

Question 4

2 types of mechanical weathering?

Answer 4

Freeze-thaw weathering and slat weathering

Question 5

What is freeze-thaw weathering?

Answer 5

Water freezing and thawing in a crack causes expansion and contraction of rock, putting and releasing pressure on rock, eventually causing rock to disintegrate

Question 6

What is salt weathering?

Answer 6

Seawater evaporates, leaving behind salt crystals. They grow and expand in cracks and holes, putting pressure on rocks, and flakes may eventually break off.

Question 7

Name a type of chemical weathering and what is it?

Answer 7

Carbonation - rainwater slightly acidic from CO2 in air. Contact with alkaline rocks such as chalk and limestone produces a chemical reaction causing rocks to slowly dissolve

Question 8

4 processes of erosion names on coast?

Answer 8

Attrition, hydraulic action, solution and abrasion

Question 9

Explain process of abrasion?

Answer 9

Eroded particles in water scrape and rub against rock, removing small pieces

Question 10

Explain process of attrition?

Answer 10

Eroded particles in water smash into each other and break into smaller fragments. Edges get rounded off as they rub together

Question 11

Explain process of hydraulic action?

Answer 11

Waves crash against rock and compress air in cracks, putting pressure on rock. Repeated compression widens cracks and makes it eventually break apart

Question 12

Explain process of solution?

Answer 12

Salts and other acids in seawater dissolve rocks on the land/cliff

Question 13

Difference between constructive and destructive waves?

Answer 13

Destructive tend to remove and erode material whereas constructive tend to deposit material

Question 14

Mass movement definition? What do they cause to coasts?

Answer 14

Downslope movement of rock, soil or mud under gravity influence. Cause coasts to retreat rapidly

Question 15

3 types of mass movement?

Answer 15

Slides, rock falls and slumping

Question 16

What is a slide?

Answer 16

Loose surface material becomes saturated and extra weight causes it to become unstable and move rapidly downhill in a straight line, sometimes in an almost fluid state

Question 17

What is rockfall?

Answer 17

Occurs on bar rock surfaces that are well jointed and prone to freeze-thaw weathering. Material breaks up and falls down slope

Question 18

What is slumping?

Answer 18

Rapid mass movement, involving a whole segment of cliff moving down-slope along a saturated shear-plane or line of weakness. Material shifts with a rotation

Question 19

Destructive wave characteristics? Height, frequency, swash and backwash strength

Answer 19

High height and frequency, strong backwash and weak swash

Question 20

3 things that determine size of waves?

Answer 20

• How strong wind is
• How long wind has been blowing
• Longer fetch equals a larger wave

Question 21

What causes waves?

Answer 21

Wind blowing over surface of sea creates friction on water’s surface. Energy is transferred