Coastal Landforms

Question 1

Properties of constructive waves

Answer 1

• strong swash
• weak backwash
• builds up a gently sloping beach
• wave crests far apart
• gently sloping wave front

Question 2

Properties of destructive waves

Answer 2

• weak swash
• strong backwash
• destroy beach creating a steep slope
• waves close together
• steep wave fronts

Question 3

describe freeze-thaw

Answer 3

• water collects in cracks or holes in rock
• at night, water freezes and expand, making cracks bigger
• when temperature rises, ice thaws (melts), it seeps deeper into rock
• repetition causes fragments of rock to break off and fall to foot of the cliff

Question 4

what is scree

Answer 4

fragments of rock that have fallen and collected at the foot of the cliff

Question 5

describe salt weathering

Answer 5

• seawater contains salt, when water evaporates, it leaves behind salt crystals
• in cracks, these salt crystals grow and expand
• this puts pressure on the rocks and flakes may eventually break off

Question 6

describe carbonation

Answer 6

• rainwater absorbs CO2 from air and becomes slightly acidic
• contact with alkaline rocks (e.g. chalk, limestone) produces a chemical reaction causing rocks to slowly dissolve

Question 7

coastal erosion - solution

Answer 7

dissolving of soluble chemicals in rocks

Question 8

coastal erosion - corrasion

Answer 8

fragments of rock are picked up and hurled by the sea at a cliff.
act like tools scraping to erode the rock

Question 9

coastal erosion - hydraulic action

Answer 9

• power of the wave as they smash onto a cliff
• trapped air is forced into cracks in rock, causing the rock to break

Question 10

coastal erosion - attrition

Answer 10

rock fragments carried by the sea knock against one another, causing them to become smaller and more rounded

Question 11

coastal erosion - abrasion

Answer 11

‘sandpapering’ effect of pebbles grinding over a rocky platform causing it to become smooth

Question 12

describe long-shore drift

Answer 12

when wave approach the coast at an angle, the sediment will be moved along the beach in a zig zag pattern

Question 13

where does coastal deposition take place

Answer 13

where the flow of water slows down
waves lose energy in sheltered bays and where water is protected by spits/bars
here sediment can no longer be carried of mvoed and is therefore deposited

Question 14

discordant and concordant coastlines

Answer 14

discordant - bands of soft and hard rock are alternating perpendicular to the coastline, meaning headlands and bays are formed

concordant - bands of soft and hard rock are aligned parallel to coastline

Question 15

how are cliffs and wave-cut platforms formed

Answer 15

• when waves break against a cliff, erosion close to the high tide line will wear away the cliff to form a wave cut notch
• over time, notch will get deeper, undercutting the cliff
• eventually overlying cliff can no longer support its own weight and it collapses
• this repeats causing the cliff to retreat
• in its place will be a gently sloping platform called a wave-cut platform
• smooth due to the process of abrasion

Question 16

Where is Swanage

Answer 16

• a seaside town in Dorset on the south coast of England
• located in a sheltered bay and has a broad sandy beach

Question 17

Structures found in Swanage coastline

Answer 17

• headlands and bays
• Old Harry Rocks
• Poole Harbour (one of the UK’s largest natural harbours)
• Studland - there are lagoons, saltmarshes and sand dunes