5 coastal landscapes Flashcards
what is weathering and its two types
the gradual degradiation of rock tyhrough erosion
mechanical- eroded naturally by wind and pressure
chemical- eroded through chemicals
what is mass movement and its three types and what does it cause coasts to do
when rocks fall down a slope
rockfall
slumps
slides
describe all four processes of coastal erosion
abrasion- when other materials rub against it
attrition- when rocks smash into each other causing them to break down into smaller rocks
hydraulic power- when pressure forms cracks in the rock qhich eventually split
describe the process of longshore drift and the roles of swash and backwash in it
1- waves move in the direction of prevailing wind
2- material is moved along the coastline through the swash which is at an angle becuase of the prevailing wind
3-material goes back into the sea through backwash
4- material gradually gets deposited along the coastline
which landforms are formed by erosion and which landforms are formed by deposition.
why is this?
erosion- wave cut platforms. headlands and bays. caves archs stacks and stumps
deposition- spits bars sand and dunes. beaches
describe the formation of headlands and bays
they occur at a discordant coastline where the rock alternates between hard and soft at a right angle to the coastline. the area of soft rock begins to be eroded much faster, causing headlands and bays
describe the formation of a wave cut platform
wave begins to erode the soft rock which is level with it. once thats been eroded it causes the rock above it to be unstable. this unstable rock then falls
describe the formation of archs caves stacks and stumps
- resistant rock has weaknesses such as cracks
- waves crash into headlands and widen the cracks
describe the formation of beaches
beaches- low energy waves cause sand beaches which are long
high energy waves cause shringle beaches which are steep and narrow
describe the formation of spits, bars and sand dunes
spits- longshore drift deposits material past the bend. strong winds then curve the end of the spit. material behind is now sheltered
bars- when two spits meet
sand dunes- deposited sand is moved up the beach by wind
what is your example of a coastline and what are its landforms
swanage bay.
- made of hard rock chalk
- hard rock was then eroded into a cliff
- cliff-arch-stack-stump
what are the four hard engineering coast management strategies along side their costs and benefits
groynes-long planks in the sea. they stop LSD but are very expensive
rock armour- a load of rocks placed to protect the clif. expensuve and ugly
gabions- rocks in a cage which protects the cliff but its expensive/ugly
sea wall- protects the cliff by being a wall but its expensive/ugly
what is the difference between hard and soft engineering
hard engineering- man made
soft engineering- natural
what are the three soft engineering coast management strategies along side their costs and benefits
beach replenishment- sand and shringle from elsewhere is added to the top of the beach
drainage channels- shows the water out of the village
dune regeneration- levelling out the dune to make it a more stable surface
what is managed retreat and its advantages/disadavantages
- allows the sea to flood the land
- that land becomes marshland therefore protecting the land behind it
- cheap and easy
why were defences needed in overstrand
area of soft rock which was too easy to erode through hydraulic action
which defences were built in overstrand
hard:
- groynes
- sea wall
- rock armour
soft:
-drainage channels
social, economic and enviromental issues in overstrand
car park, houses and businesses are lost. exponentially increasing over time
four examples of transportation
saltation
suspension
traction
solution
difference between a discordant and a concordant coastline
discordant- hard rock and soft rock alternates at a right angle to the coastline
concordant- hard rock and soft rock alternates parallel to the coastline
what was the effects of the defences put in place in overstrand
successfull at slowing erosion down and stopping LSD but they eventualy broke
