Slides in this set
Hard rock-Granite, Lands End:
1. High rugged steep.
2. Cliff face has no vegetation. Little loose rock
Soft rock-Scarborough, Yorkshire.
1. High, not so rugged, not so steep.
2. Plies of mud/clay slipped down the cliff.
1. Sea attacks base of the cliff, due to hydraulic action a wave cut notch is formed.
2. Wave cut notch gets bigger causing the base of the cliff to be weak and unstable causing the cliff to collapse.
3. Backwash carries rubble out to sea which rubs which due to abrasion against the base of the cliff turns into a wave
4. This process repeats itself and the cliff retreats.
1. Waves containing sediment and rocks enter the cracks in weak areas of the rock. Over time the sediment grinds
against the cracks causing it to wear over time and grow larger. The cracks grow larger and larger until they become a
cave. This is a hydraulic action.
2. The cave gets bigger and bigger until it breaks through to the other side forming an arch.
3. The arch will continue to get eroded by hydraulic action until it can no longer support its roof, so the roof collapse
breaking the arch away from the mainland forming a stack.
4. The waves then attack the base of the stack (same as how the waves attack the base of a cliff to form a wave cut
notch). The stacks base eventually gets very weak and collapses forming a stump.…read more
Rock is the same type along the coastline=concordant.
Different layers of rock at right angles to the coast= discordant.
Joints= natural small cracks
Faults=larger cracks caused by tectonic plate movement.
1. Friction between the wind and water is what cause a wave.
Factors that affect how large a wave is:
1. The strength of the wind.
2. The distance of the water the winds blown over=the fetch.
3. How long the wind blow for.
How a wave breaks:
1. Each water particle travels in a circular shape, its only the energy that's travelling not the water itself.
2. When the wave reaches shallow water, water particles travel shape goes from circular to elliptical. Cause wave to be
top heavy so wave breaks causing the energy and wave to go forward.
Constructive waves= long wavelengths, low amplitude, large swash so a lot of sediment is deposited on the beach
causing the beach to build up.
Destructive=larger amplitude, shorter wavelength so are taller. Larger backwash, small swash, so takes sediment away
from beaches. Steep beach is formed.
Longshore Drift= continual swash and backwash carries sediment along a coastline. In the direction of the wind, in a
Spits=formed at the end corner of a coastline as LSD still continue and deposits sediment in a curved shaped due to the
wind and waves. Salt marshes form in the corner of a spit.
Bar=when a spit form between two mainlands to join them together.
Tombolo=when a spit forms between a mainland and island and joins them together.…read more
Low lying areas at risk due to a rise in sea levels due to ice caps melting and thermal expansion (water droplets exapnd
when heated). E.g. Bangladesh.
1. Storm surges happen when spring tides and low pressure occur at the same time.
2. Huge waves would flood the coast.
3. More storm surges and rising sea-level would mean there would be faster erosion.
4. Current sea defences would be useless in a couple years time, new ones are expensive.…read more
1. Sea wall:
-Reflect waves back out to sea
-Hard to access beach
-Ugly to locals
-Would eventually erode so the maintenance costs are high
-Stops longshore drift as the wave is dissipated (wave has no energy left).
-Build up a nice sandy beach good for tourism.
-Little sediment reaches further along the coast as longshore drift has been stopped, causing the beaches further along
the coast to be less sandy causing conflict e.g. Due to loss of tourism for them,
3. Rock armour
-Kept at base of the cliff so wave is dissipated.
-Boulder, so natural looking.
-Harder to access the beach though.
-Concrete slatted structure built at the foot of the cliff.
-Absorbs and spreads out energy of the wave.
-Doesn't interfere with longshore drift
Hard engineering for: Help save locals housing, businesses etc. Against: If I don't live near the coast why should I pay,
environmentalists worry habitats are going to be destroyed.…read more
-Planting vegetation to make cliff more stable
-Offshore breakwaters to break up the cliff before it reaches the coast.
-Managed Retreat- Businesses and homes retreat away from the coastline
-Beach Nourishment-Sand is pumped onto the beach but due to longshore drift it has to be done repeatedly as
otherwise it would travel further down the coastline.
-Cliff Regrading-Making the cliff face longer so its less steep.
Holistic Management=takes into account not only 1 place, but the entire coastline
For things council can do:
1. Advance the Line= Build the coast further into sea, extremely expensive.
2. Hold the line=use defences to stop the coast from retreating and keep it where it is. Expensive.
3. Strategic retreat=move houses and businesses away from the coastline. Use no defences against the coastline,
however compensation must be given.
4. Do nothing = let nature take its course.
SMP = shoreline management plans.…read more
Holderness Coatline, East Yorkshire.
1. Cliffs made of soft glacial material = easily eroded.
2. Destructive waves = sediment washed out to sea = longshore drift carries a lot of sediment further long coastline =
left with a narrow beach = not much protection from the waves = eroding base of cliffs from hydraulic aaction.
3. Exposed to waves with long fetchs = more energy = more erosion
4. Sea level rising = more erosion
What they did:
1. Groynes to trap sediment, build up a sandy beach as protection.
2. Sea wall + revetments at base of the cliff to dissipate waves at the base of the cliff.
3. Sea wall used to protect Easington gas station worth 4.5 million pounds.
4. artificial offshore breakwaters made of concrete break waves before they reach the shore.…read more