Physical Landscape Creating features

Question 1

Headlands and bays

Answer 1

• DISCORDANT COASTLINES

1) waves perpendicular to coast line corrasion erodes less resistant rock creating bays
2) headlands stick out so wave refraction occurs causing hydraulic action on sides
3) when the waves reach the bays they don’t have as much energy so deposition occurs and creates beaches

Question 2

Cliffs retreating

Answer 2

• CONCORDANT COASTLINE

1) corrasion causes wave-cut notch, freeze-thaw weathering weakens top
2) overhang collapses due to gravity, corrasion continues using material from overhang
3) Cliff retreats further and a wave cut platform is produced, smooched by abrasion, shows at low tide

Question 3

Sand dunes creation

Answer 3

1) Wind transport sand up the beach and deposits it forming an embryo dune (hard to colonise: saline, low fertility, windy)
2) presence of marram grass changes conditions: new species colonise, Greater fertility leads to soil, marram grass traps sand so new dune develops protecting dune A (shrubs like heather +gorse colonise)
3) eventually dune A has the right conditions to support a climax community deciduous woodland: soil, shelter, freshwater

Question 4

Formation of a waterfall and gorge

Answer 4

• occurs when river flows over resistant rock and then less resistant rock

1) The less resistant rock erodes faster
2) vertical erosion + power of water falling deepens plunge pool
3) hydraulic action erodes less resistant
4) overhang collapses due to gravity
5) rocks from overhang are used for abrasion of less resistant rock so process continues + waterfall retreats

Gorge: is a narrow, steep-sided valley found downstream of a retreating waterfall

Question 5

How oxbow lakes form

Answer 5

1) erosion and deposition occur on opposite sides of the lake which causes lake to migrate
2) deposition on the inside of the bend eventually cuts off meander
3) deposition on edge of river channel cuts oxbow lake off from main channel, water will evaporate

Question 6

Formation of spit

Answer 6

1) constructive waves approach coast and transport material
2) when coastline changes direction, long sure drift continues building a spit
3) split grows across Esturary but presence of river prevents it from becoming a bar and the secondary wind direction creates a hook
4) River deposit material behind the spit because it is sheltered making a salt marsh

Question 7

Land formations from a spit

Answer 7

Bar: spit that extends across the bay, lagoon behind eventually evaporates and creates a salt marsh

Tombolo: when a spit connects mainland to an island

Question 8

Erosion of headland

Answer 8

1) Crack: caused by waves
2) Cave: hydraulic action in cracks
3) Arch: Corrasion widens cave
4) stack: freeze-thaw weathering weakens arch
5) stump: abrasion + corrasion = wave-Cut notch