Geography Landscapes-paper 1 (Landscapes (Coastal erosion - (Coastal…
Geography Landscapes-paper 1
Coastal erosion -
Coastal Landforms Caused by Erosion -
Wave Cut Plat Forms -
3)The rock above the notch becomes unstable and collapses.
4)The collapsed material is washed away and a new wave-cut notch starts to form.
2)This forms a wave-cut notch, which is enlarged as erosion continues.
5) Repeated collapsing results in the cliff retreating.
1) Waves cause most erosion at the foot of a cliff.
6)A wave-cut platform is the platform that's left behind as the cliff retreats.
Headlands and Bays Form Where Erosion Resistance is Different -
2)Headlands and bays form where there are alternating bands of resistant and less resistant rock along the coast
3)The less resistant rock(clay) is eroded quickly and this forms a bay, have gentle slopes.
1) Soft rocks have low resistance to erosion, hard rocks have high resistance.
4) The resistant rock(chalk) is eroded more slowly and it's left jutting out, forming a headland, steep slopes.
Headlands are Eroded to form Caves, Arches and Stacks -
3)Repeated erosion and enlargement of the cracks a cave to form.
4)Continued erosion deepens the cave until it breaks through the headland forming an arch e.g. Durdle Door in Dorset.
2) Waves crash into the headlands and enlarge the cracks mainly by hydraulic power and abrasion.
5) Erosion continues to wear away the rock supporting the arch until it eventually collapses.
1) Headlands are usually made of resistant rocks that have weaknesses like cracks.
6)This forms a stack and isolated rock that's separate from the headland e.g. Old Harry in Dorsey.
Coastal Transportation and Deposition -
3)The swash carries material up the beach, in the same direction as the waves.
4)The backwash then carries material down the beach at right angles, back towards the sea.
2)They usually hit the coast at tan oblique angle.
5)Over time, material zigzags along the coast.
1)Waves follow the direction of the prevailing wind.
Suspension - small particles like silt and clay are carried along in the water.
Saltation - pebble sized particles are bounced along the sea bed by the force of water.
Traction - large particles like boulders are pushed along the sea bed by the force of the water.
Solution - soluble materials dissolve in the water and are carried along.
2)Coasts are built up when the amount of deposition is greater than the amount of erosion.
3)The material is increased when lots of erosion elsewhere on the coast, lots of transportation of material into the area.
1)Material carried by sea water is dropped on the coast. When the sediment slows down and isn't fast enough.
4)Low energy waves carry material to the coast but they're not strong enough to take a lot of material away - this means there's lots of deposition and very little erosion.
Constructive waves deposit more material.
1)Constructive waves have a low frequency.
2)Low and Long.
3)The swash is powerful and it carries material u[ the coast.
4)Backwash is weaker and it doesn't take a lot of material back down the coast.
Coastal Weathering and Erosion -
Mass movement -
When coastline rocks are weakened by weathering and collapse under the influence of gravity, causing coasts to retreat rapidly
Slumps - material shifts with a rotation.
Rock falls - material breaks up and falls down a slope.
Slides - material shifts in a straight line.
Weakens rock structure by chemical, biological or mechanical means.
Chemicals in sea or rain that alter the structure of rock such as acid rain dissolves carboniferous limestone.
Living things burry or grow in the structures of rick like tress, bushes or animals.
Physical breakdown of rocks due to freeze thaw. Freezing puts pressure on the rock and then thaw realises the pressure repeated causes cracks.
Abrasion - eroded particles in the water scrape and rub against rock, removing small pieces.
Attrition -rocks and pebbles in the water smash into eachother.
Hydraulic power - waves crash against rock and compress the air in the cracks putting pressure on the rock making it crack.
Solution - Acids within the sea water dissolve some types of rock easily eroding them.,
Destructive waves are high and steep, the backwash is more powerful than their swash.
Identifying Coastal Landforms -
Landforms Caused by Erosion -
Caves, Arches and Stacks-
1)Cliffs are shown on maps as little black lines.
2)Wave-cut platforms are shown as bumpy edges along the coast.
Cliffs and Wave-cut Platforms -
1)Caves and arches can't be seen on a map because of the rock above them,
2)Stacks look like little blobs in the sea.
Landforms Caused by Deposition -
1)Sand beaches are shown on maps as pale yellow.
2)Shingle beaches are shown as white or yellow speckles.
1)Spits are shown by a beach that carries on out to sea, but is still attached to the land at one end.
2)There might also be a sharp bend in the coast that caused it to form.
Coastal management Strategies -
Hard Engineering -
Groynes - Timber or rock structures, that trap sand - creates wider beach - problem goes to another beach - Eastbourne Sussex
Rock armour - piles of boulders at foot of cliffs - very cheap and easy to maintain -don't fit local geology - Naze Essex
Sea wall - Concrete barrier placed at foot of cliffs - effective at stopping sea - very expensive, unnatural - Dualsh Devon
Gabins - wire cages with rocks - merge into landscape - cages lost 5-10 years - Thurpness Suffock
Soft Engineering -
Beach Nourishment and Reproofing - Sand and shingle from elsewhere - creates wider beaches which slow the waves - taking material from the seabed can kill organisms, very expensive.
Dune regeneration - Creating or restoring dunes - Provide a barriers which absorbed the wave energy - The protection is limited to a small area.
Managed Retreat -
Works at Medberry west Sussex by creating a large natural saltmarsh to form a natural buffer to the sea, help protect surrounding farmland and Caravan parks from flooding establish a valuable wildlife habitat and encourage visitors to the area.
Coastal Landscape -
Lulworth Cove -
Small bay formed after a gap was eroded in a band of limestone. Behind the limestone is a band of clay, which has been eroded away to form the bay. The same is now starting to happen at Stair Hole further west along the coast.
Chesil Beach -
Tombolo (a type of bar) formed by longshore drift. It joins the Isle of Portland to the mainland. Behind Chesil Beach is a shallow lagoon called The Fleet Lagoon.
Durdle Door -
Great example of an arch-Erosion by waves opened up a crack in the limestone headland, which became a cave and then developed into an arch.
Swanage Bay, The Foreland and Studland Bay -
There are two bays with beaches called Swanage bay and Studland Bay. They're areas of softer rock (sandstone and clay). In between them is a headland called The Foreland made from a band of harder rock (chalk). The end of the headland has been eroded to become a stack called Old Harry and a stump called Old Harry's Wife.
The Dorset coast is made from bands of hard rock (like limestone and chalk) and soft rock (like clay).
Coastal Management - Example -
In 1991, 450 m of coastline around Mappleton was protected at a coast of £2 million, and using over 61000 tonnes or rock. Built two groynes. This protects two towns, Hornsea and Mappleton. Important infrastructure like the B1242 road and a gas terminal which supplies 25% of the UK's gas.
Coastal Landforms Caused by Deposition -
Beaches are formed by Deposition -
2) Destructive waves destroy the beach's taking away the sand we use hard or soft engineering to counteract this.
1) Formed by constructive waves depositing material like sand and shingle.
3)Strong winds and waves can curve the end of the spit (forming a recurved end).
2)Longshore drift transports sand and shingle past the bend and deposits it in the sea.
4)The sheltered area behind the spit is protected from waves - lots of material accumulates in this area, which means plants can grow there.
1)Form at sharp bends in the coastline.
5) Over time, the sheltered area can become a mud flat or a salt marsh.
2)The bar cuts off the bay between the headlands from the sea.
3)This means a lagoon can form behind the bar.
1)A bar is formed when a spit joins two headlands together.
Sand Dunes -
2)Obstacles can cause wind speed to decrease so sand is deposited. The vegetation stabilises the sand and encourages more sand to accumulate there.
3)Over time, the oldest dunes migrate inland as newer embryo dunes are formed. These mature dunes can reach heights of up to 10m
1)Formed when sand deposited by longshore drift is moved up the beach by the wind.
Glacial Landscapes -
Identifying Glacial Landforms -
are really thin hill with tightly packed, parallel contours on either side.
are flat valets with very steep sides. N0 c0nt0ur lines on the bottom of the valley but they're tightly packed on the sides.
has tightly packed contour line that curve away from a central high pint. If you find this you'll find the arêtes and corries around it.
in them. Flat valley with steep sides surrounding a long straight lake.
have tightly packed contours in a U-shape around them.
Glacial Landscape - Example - Snowdonia - North Wales
A lot of moraine can be found around Llyn Idwal, where it was deposited by the melting glacier.
Llyn Ogwen is an example of a ribbon lake.
Llyn Bochlwyd and Llyn Idwal are tarns. They sit in hollowed out corries above the main valley.
Nant Ffrancon is a glacial trough. You can see the large U-shaped valley and the River Ogwen that looks too small to have created it.
The sharp ridge between the two corries known as Y Gribin is an example of an arête. At its lower end, it is cut off by the Ogwen valley leaving a truncated spur.
Glacial Deposition -
Medial moraine -
is a long ridge if natural deposited along the centre of a valley floor. When two glaciers meet, the lateral moraines from the two edges join and form a line of material running along the centre of the new glacier.
Terminal moraine -
builds up at the snout of the glacier marking the furthest point reached by the ice. Material that's abraded and plucked from the valley floor is transported at the front of the glacier and then deposited as semi-circular mounds as the ice retreats.
Lateral moraine -
is a long mound of material deposited where the side of the glacier was. It's formed by material eroded from the valley walls and carried along on the ice surface at the sides of the glacier.
Ground moraine -
us eroded material that was dragged along the base of the glacier and is deposited over a wide area on the valley floor as the ice melts.
Are elongated hills of glacial deposits - the largest ones can be over 100m long, 500m wide and 50m high.
They're round, blunt and steep at the upstream end, and tapered, pointed and gently sloping at the downstream end.
Erratics often look out of place
Are rocks that have been picked up by a glacier, carried along and dropped in an area that has a completely different rock type.
Land Use in Glacial Landscapes -
Economic Uses -
Glaciated areas have dramatic landscapes making them attractive places to vising - People take part in many activities.
Provides building materials valuable resources - making cement
Sheep farming on steep slopes - Cattle are sometimes kept on flatter valley floors - Crops in valleys.
Coniferous forests are often planted in upland areas because they can cope with the cold weather and high rainfall.
Glacial Landforms -
Different Landforms -
begin as hollows containing a small glacier, As the ice moves by rotational slip its erodes the hollow into a steep sided, armchair shape with a lip at the bottom end. When the ice melts it can leave a small circular lake called a tarn. e.g. Red Tarn
Truncated Spurs -
are cliff like edges on the valley side formed when ridges of land (spurs) that stick out into the main valley are cu off as the glacier moves past.
Ribbon lakes -
are long, tin lakes that form after a glacier retreats. They form in hollows where softer rock was eroded more then the surrounding hard rock. e.g. Windermere
Hanging Valleys -
Valleys formed by smaller glaciers that flow into the main glacier. The glacial through is eroded much more deeply by the larger glacier, so when the glaciers melt the valleys are left at a higher level.
Pyramidal peak -
is a pointed mountain peak with at least three sides. it's formed when three or more back to back glaciers erode a mountain.
Glacial troughs -
are steep-sided valleys with flat bottoms. They start off as a V-shaped river valley but change to a U--shape as the glacier erodes the sides and bottom making it deeper and wider. e.g. Nant Ffrancon
is a narrow, steep-sided ridge formed when two glaciers flow in parallel valleys. The glaciers erode the sides of they valleys. The glaciers erode the sides of the valleys, which sharpens the ridge between them giving it a jagged profile. e.g. Lake District.
Tourism in Glacial Landscapes -
Social Impacts -
2)Shops that used to sell goods for local people now sell gifs for tourists.
3)Holiday homes are usually not occupied all tear round, lead to some services not being limited e.g. reduced bus services.
1)Increased traffic problems, congestion is common and not enough car parking.
Environmental Impacts -
3)Water sports create noise pollution, waves created by the bots can erode the shoreline.
4)Tourists may park on grass verges causing damage to vegetation.
5)Wildlife and livestock can be disturbed by walkers and their dogs.
1)Footpath erosion , vegetation destroyed and soil washed away.
Economic Impacts -
2)Offers employment to local people. Jobs are seasonal and low paid.
3)Extremely high house process due to the demand for holiday and second homes meaning locals are forced out of the area.
1) Positive economic impact on glacial landscapes on main industry.
4)Price of goods and services is often higher as tourists will pay more.
2)Managing traffic congestion: Increase public transport - improve the road network - encourage use of bikes, buses.
3)Protecting wildlife and farmland: Use signs to take their litter home - encourage visitors to enjoy the countryside responsibly by closing gates and keeping dogs on leads.
1)Managing footpath erosion: resurface paths with hard-wearing materials - Encourage visitors to use alterative routes - Reseed vegetation.
Glacial Erosion -
Plucking - occurs when meltwater at the base, back or sides of a glacier freezes onto the rock. As the glacier moves forward it pulls pieces of rock out.
Abrasion - Where bits of rock stuck in the ice grind against the rock below the glacier wearing it away(like the glacier has sandpaper on the bottom of it)
Tourism in Glacial Landscapes - Examples
The Lake District is a National Park in Cumbria, which gets 16.4 visitors every year. The attractions for visitors include : beautiful scenery, cultural attritions e.g. Beatrix Potter's House, activities.
Tourism impacts -
Economic Impacts -
1)Employed over 16000 people in 2014 and visitors spent £1 billion.
2)Average price of £350000 but the average local household income is only £27000.
Social Impacts -
2) Businesses in the village of Ambleside mostly cater for tourists. This makes costs high and locals travel to Kendal to buy food and cloths.
3)16% of homes in the national park are second or holiday homes, meaning fewer people living in the National park all year round, so bus services are limited and some schools are closed.
1)Traffic is heavy as 89% of visitors arrive by car.
Environmental Impacts -
2)Noise, erosion and pollution of water with fuel is caused by boats and water sports on Lake Windermere.
1) Tourists often park on the grass verges in the popular Langdale valley, which damages the vegetation.
Management Strategies -
2)High property prices - 134 affordable homes were built - 141 houses that only locals can buy.
3)Erosion of footpaths - Severely eroded paths have been covered with soil and reseeded, main routes have been gravelled.
1)Reduce car traffic use by only allowing people to use the car park for an hour and pay as you go bikes.
4)Coping with Water sports - Zoning schemes so only some water sports are only allowed in certain areas of some lakes e.g. Windermere has a 10 knot speed limit for all boats which falls to 6 knots in some zones.