Paper 1 Flashcards
What is a coastline?
a coastline is where the sea and land meet. they constantly change due to the action of the sea, weather and humans.
what are the characteristics of a destructive wave?
weak swash tall breaker short wave length strong backwash breaks downwards with great force 12-15 per minute
what are the characteristics of a constructive wave?
strong swash weak backwash long wave length 7-10 per minute long in relation to its height
what is a wave?
the movement of the wind across the surface of the sea
what is corrosion?
this is the chemical action of sea water. the acids in the salt water slowly dissolve rocks on the coast. limestone and chalk are particularly prone to this process.
what is attrition?
the process in which the coast is worn down by material carried by the waves. waves throw these particles against the rock, sometimes at high velocity.
what is corrasion/ abrasion?
materials carried by the waves bump into each other and so are smoothed and broken down into smaller particles
what is hydraulic action?
the waves enter cracks (faults) in the coastline and compress the air within the crack. when the wave retreats the air in the crack explodes quickly. causing a mini explosion, this carries on continuously
explain traction
some heavy rocks get dragged across the sea bed by the water. because they are too heavy to float
explain saltation
some rocks get picked up by the sea, then dropped right away. the rocks bounce off the seabed and move forward
explain suspension
some small rocks get lifted by the sea and are carried to the shore eg clay
explain solution
these rocks are alkali and dissolve into the water. then it is carried onto the sea shore
explain mechanical weathering
1) water seeps into joints
2) water freezes overnight and expands in volume by 8% (10% is ok)
3) the ice thaws and freezes countless times which applies pressure on the rock
4) the rock shatters which creates scree
what is biological weathering?
1) seeds blow into joints and grow
2) roots develop and widen the joints
3) joints break apart
4) small pieces of scree are developed
what is chemical weathering?
1) rain mixes with gases (co2) in the air
2) acid rain falls into rock (limestone)
3) acid rain dissolves the metal carbonates of the limestone
4) the process is known as solution
explain slumping?
slow
series of steps
rainwater saturates the rock until it starts to slowly slump down
occurs in Holderness Coastline
explain sliding (landslide)
sudden collapse
in hard rock areas
eg beachy head
how is a bay formed
waves erode the soft rock inbetween the headlands, soft rock eg clay. via abrasion (sea throwing material)
the remaining hard rock is known as headlands and the soft rock that’s eroded is known as a bay
explain cliff erosion/ how a cliff collapses
destructive waves throw sediment at base of the cliff (abrasion) known as undercutting. creates a wave cut notch, makes it unstable.
the process repeats itself as the wave cut platform grows in length until the cliff collapses under gravity.
explain how a cave, arch, stack and stump are caused in order.
destructive waves attack a fault in a headland via abrasion and enlarge it. repeats until a cave is formed.
back of cave is eroded through to form an arch
roof of arch collapses as it’s base is widened via sea erosion.
makes a stack
stack is undercut and collapses to make a stump
why is the holderness coast the fastest eroding coastline
made of soft boulder clay
what happens south of protected areas on the holderness coast
waves are refracted and target the unprotected area
where does the fetch come from to reach the holderness coast?
norway
explain LongShore Drift
the movement of sediment along the coastline. enters with a 45 degree angle (swash) and exits at 90 degree (backwash)
meaning material is drifting along the beach
how much metres of farmland is lost each year on the holderness coast
2m a year
how much have houses prices dropped by on the holderness coast
90%
how much did hornseas sea wall to make
£8 million
how is a spit formed (spurn head)
one end is attached to land other is attached to open sea
by LSD, when the sea is slowed deposition takes place. fresh water and sea water are trapped behind the spit.
as the spit extends into deeper water the end of the spit is affected by strong winds and it curves
how is a bar formed
a bar is a ridge of sand and shingle that crosses the entrance to a bar, some go all the way across to cut off access via sea meaning it becomes a lagoon rather than a bay.
3 examples of hard engineering
rip rap
groynes
sea walls