1.2- Coastal Landscapes Flashcards
What are the 3 types of weathering?
chemical, biological and mechanical
What is chemical weathering?
rocks reacting with slightly acidic water
What is biological weathering?
action of plants and animals causing the rocks to widen and split apart
What is mechanical weathering?
water falls into the cracks in rocks and freezes, causing it to expand. over time the repeated thawing and freezing causes the rocks to break apart
What is mass movement?
the downhill movement of material under the influence of gravity
What are 4 types of coastal erosion?
abrasion, attrition, hydraulic action and soloution
What is abrasion?
breaking waves containing sand erode the shoreline or headland. It is also known as the sandpaper effect.
What is hydraulic action?
The sheer weight and impact of water compressing air in rock joints forcing them apart.
What is attrition?
rocks and pebbles carried by waves smashing together and breaking into smaller pieces
what is solution? (erosion)
the chemical action of seawater dissolving some rocks
What is soil creep?
individual particles of soil moving down a slope under 5he influence of gravity
What is sliding?
where material moves rapidly downslop in one go like a landslide.
What is slumping?
when the ground also rotates
What are flows?
masses of with water flowing like a liquid downhill
What what causes rain to become more acidic?
pollution
What is longshore drift?
the process at which sand is transported along the beach by waves.
What is traction?
large boulders being rolled along the seabed
What is salatation?
smaller stones being bounced along the seabed.
What is suspension?
sand and small particles being carried along in the flow
what is solution? (transportation)
some minerals being dissolved in seawater and carried along with the flow
What is deposition?
the dropping of sediment
What is the process of longshore drift?
waves approach the coastline at an acute angle. bringing sediment onto the beach with the swash. sediment is then dragged back down by the backwash under the force of gravity at a right angle. this process continues in a zig zag pattern moving sediment along the beach.
what is a constructive wave?
a wave that deposits sand
swash is stronger than backwash
low energy
occur in calm conditions
what is a destructive wave?
a wave that erodes sand
swash is weaker than backwash
high energy
occur in stormy conditions
what is a concordant coast?
A coast that is made up of the same type of rock
what is a discordant coast?
a coast that is made up of many different types of rock. it forms headlands and bays because some rock is erodes faster.
what are joints?
smaller cracks in rocks
what are faults?
larger cracks in rocks
what are some effects of stormy weather?
mass movement contribution frequent storms erode landforms beach sediment is removed sand dunes can be removed by storms flooding causes soil saturation
what is coastal erosion?
the breakdown and removal of material along the coast
what is coastal retreat?
when coastal erosion causes the coastline to move further inland
what type of coastlines do headlands and bays develop on?
discordant ones
hows are cliffs formed?
through weathering and erosion
how are caves formed?
when the waves erode a weakness in the rock like a joint or fault
how are arches formed?
when 2 caves erode from either side and meet in the middle
what is a wave cut platform?
areas of flat rock at the bass of the cliff
how are beaches formed?
the accumulation of sand and shingle formed by deposition and shaped by erosion
What are spits?
narrow beaches of sand and shingle that are attached to land at one end. they extend across a bay or estuar
what is a bar?
a spit that extends further and is joined at both ends
how are bars formed?
a bar forms in the same way as a spit, with longshore drift depositing materialaway from the coast until a long ridge is built up. but unlike a spit, a bar then grows all the way across the bay so that a stretch of water is cut off to form a lagoon.
what landforms does deposition form?
beaches
spits
bars
why is urbanisation bad for coasts?
the weight of the buildings makes cliffs more vunerable
changes to drainage increases soil saturation
why is agriculture bad for coasts?
it increases soil erosion
it increases sedimentation
why is industry bad for coasts?
it increases air, noise and pollution
it can destroy animal habitats
what are the advantages and disadvantages of seawalls
protect cliffs very expensive(£10000/metre) restrict access to the beach
what are the advantages and disadvantages of Groynes?
prevent sea removing sand
cheaper (£2000/metre)
what are the advantages and disadvantages of rip rap defences?
rocks absorb wave energy
cheaper (£3000/metre)
what are the advantages and disadvantages of beach replenishment?
reduces wave energy
maintains tourism
cheaper (£2000/ metre)
what are the advantages and disadvantages of offshore reefs?
waves break on reef and lose power more expensive (£5000/ metre)
