coastal landforms

Question 1

discordant coastlines

Answer 1

discordant coastlines are made up of alternating bands of hard and soft rock at right angles to the coast

Question 2

concordant coastlines

Answer 2

alternating bands of hard and soft rock are parallel

Question 3

what can affect the rate of erosion
rock type and geological structure influence erosional landforms

Answer 3

hard rocks like granite take longer and soft rock like sandstone take a shorter amount of time
rocks with joints and faults like cracks erode faster

Question 4

headlands and bays form along what coastline

Answer 4

discordant - alternating bands of less resistant and resistant rock along a coast
less is eroded faster forming a bay with a gentle slope
because the resistant rocks erodes more slowly it juts out forming a headland with steep sides

Question 5

headlands are eroded forming caves, arches and stacks

Answer 5

• resistant rock likely has weaknesses like cracks
• waves crash into headlands and enlarge the cracks by hydraulic action and abrasion
• repeated erosion cause a cave to form
• continued erosion deepens the cave until it breaks through the headland to form the arch
• erosion wears away the rock supporting the arch until it eventually collapses
• this forms a stack

Question 6

waves erode cliffs to form wave - cut platforms

Answer 6

waves cause most erosion at the foot of a cliff, forming a wave cut notch which is enlarged over time
repeated erosion causes the rock and notch to become unstable and it collapses
collapsed material is washed away and a new wave cut notch starts to form
after repeated collapses the cliff retreats leaving a wave - cut platform e.g. Southerndown, South Wales

Question 7

beaches are formed by deposition

Answer 7

beaches are found on coasts between the high and low water marks
formed by contructive waves

Question 8

sand beaches

Answer 8

created by low energy waves and are flat and wide - sand particles are small so the weak backwash can move them back down the beach creating a long gentle slope

Question 9

shingle beaches

Answer 9

created by high energy waves and are steep and narrow - sand particles are washed away but larger shingle is left behind - the shingle particles build up to create a steep slope

Question 10

spits

Answer 10

form at sharp bends in the coastline - lngshore drift transports sediment and desposits it past the bend - wind and wave can curve the end of the spit

Question 11

bars

Answer 11

when a spit joins two headlands - bay gets cut off - lagoon can form behind the bar

Question 12

sand dunes

Answer 12

embryo dune - foredune - mature dune - occurs when sand deposited by longshore drift is pushed up the beach by winds - obstacles like driftwood decrease wind speed so sand is deposited

Question 13

how to identify cliffs on a map

Answer 13

little black lines

Question 14

how to identify stacks

Answer 14

little blobs in sea