GSCE AQA GEOGRAPHY - coasts

what are the 3 terminal terms?

quality of life, standard of living, biodiversity

what is hydraulic action?

force water through crack

what is attrition?

rock smashing together to make them smaller and rounder

what is solution?

dissolved rocks

what is abrasion?

rocks hitting the cliff face

what is the different between soft rock and hard rock?

soft rocks are younger and less resistant hard rocks are older and more resistant

what is boulder clay?

boulder clay is made up of bits of rocks and dirt that have been eroded then deposited

what is a headland?

headland is where the underlying rock is more resistant to erosion

what is a bay?

bay is where less resistant clay and sand are

what is fetch?

fetch is the length of water the wind blows over

what is geology?

the study of rocks and their impacts

what is eroded material?

the material that has been broken down

what is swash?

swash is the depositing of sediment onto a beach

what is backwash?

backwash is the taking away of material from the beach

What is a wave cut notch?

wave cut notch is the eroded part that the wave has hit

what is weathering?

weathering is the wearing away of rocks by the atmosphere

what is freeze thaw?

the repetion of water getting into crack and freezing causing it to expand and break in half

What are bedding planes?

Zones of weakness cause fractures between layers in sedimentary rocks

what are vertical joints?

they are vertical cracks in the cliff they are very vulnerable to erosion

what are horizontal bedding planes?

they are horizontal cracks that are weakness in the rock

How are wave-cut notches formed?

sea attacks base fo clif by hydraulic action and abrasion. notch becomes unstable and eventually collapses

How are wave cut platforms formed?

a notch increases in size becomes unstable retracts leaving behind the platform

where are headlands and bays formed?

discordant coastline

what are the different types of rock on a discordant coastline?

headlands made of granite bays made of clay

what are the characteristics of constructive waves?

low energy, large swash, small backwash, small in height

what are the characteristics of destructive waves?

high energy, small swash, large backwash, large in height

what is deposition?

water slows down and waves lose their energy leaving behind the sediment

what is longshore drift?

the movement of sediment depending on the direction of the waves

where spits formed?

they are formed on discordant coastlines

How are spits formed?

By longshore drift sediment is deposited by a headland

how is a stump formed?

1. lines of weakness in the rocks are vulnerable to erosion 2. abrasion and hydraulic action widen the joint forming a cave 3. erosion leads to it breaking through causing and arch 5. leaves an isolated stamp 6. stack eroded and collapses

what is a sea wall?

they are concrete or rock barriers at the foot of the cliff of top of the beach. they are curved out to reflect the wave

what are the advantages of sea wall and how much do they cost?

effective at stopping the sea, often create a walk way. they cost around 5000- 10000 per metre

what are the disadvantages of sea walls?

they can look obtrusive and unnatural also they are expensive and high maintenance

what are groynes?

groynes are rock or timber structures built at right angles to the beach. they trapped moved sediment from longshore drift and enlarge the beaches

what are the advantages of groynes and how much do they cost?

creates a wider beach and not too expensive. they cost 150000 per 200 metres

what are the disadvantages of groynes?

they interrupt longshore drift can lead to increased erosion, also look unnatural and unattractive

what are rock amour ?

they are piles of large boulders at the foot of the cliff. the rocks absorb waves energy to protect the cliff

what are the advantages of rock amour and how much do they cost?

relatively cheap, easy to maintain and can add interest to the coast. they cost 200000 per 100 metres

what are the disadvantage of rock amour?

the rock don't fit with local geology, expensive to transport rocks, can be obtrusive

what are gabions?

they are rock filled wire cages that support a cliff and provide a buffer against the sea

what are the advantages of gabions and how much do they cost?

cheap to produce, improve drainage of the cliff ,can become eventually vegetated and merge into landscapes. they cost 50000 per 100 metres

What is beach nourishment?

the using of sand or shingle is dredged offshore and transported to the coast barge and dumped on the beach

what are the advantages of beach nourishment and how much do they cost?

blends in with existing beach, bigger beach increases tourists potential. they cost 500000 per 100 metre

what are the disadvantage of beach nourishment?

need constant maintenance and they are expensive

What is dune regeneration?

marram is planted to stabilise dunes and help them develop

what isthe advantages of dune regeneration and how much do they cost?

maintains a natural environment and good for wildlife, relatively cheap. they cost 200- 2000 per 100 metre

what are the disadvantages of dune regeneration?

they are time consuming to plant grass and construct fencing, can be damaged by storms

where is Dorset located?

it is located in the south of england on the coast

what examples does dorset have?

swanage is example of headland and bay, old harry is an example of caves, stacks and stumps and chesil beach is an example of a bar