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neurologyYou need to know

• The coast is the meeting point between the land and the sea.
• Coastal processes include marine processes that act offshore and terrestrial processes that act onshore.
• Coastal processes shape coastal landscapes through wave action, erosion, transportation, deposition, weathering and mass movement.
• Waves form when wind blows across the surface of the sea.
• Wave size increases when wind strength is greater, wind blows for longer and the fetch is longer.
• As waves enter shallow water, friction with the seabed causes the wave to slow, steepen, break and move water onto the shore.
• Swash is the movement of water up the beach and backwash is the movement of water back down the beach.
• Constructive waves have a strong swash, a weak backwash, a long wavelength, a low height and a low frequency of about 6 to 8 waves per minute.
• Constructive waves deposit sediment and help to build wide sandy beaches.
• Destructive waves have a weak swash, a strong backwash, a short wavelength, a high height and a high frequency of about 10 to 12 waves per minute.
• Destructive waves remove beach material and are responsible for most coastal erosion.
• Weathering is the breakdown of rock in situ without the movement of material.
• Mechanical weathering breaks rock into smaller pieces without changing the rock's chemical composition.
• Freeze-thaw weathering happens when water enters cracks in rock, freezes and expands, and repeated freezing and thawing widens the cracks until pieces of rock break off.
• Chemical weathering happens when slightly acidic rainwater reacts with minerals in rock and gradually decomposes the rock.
• Limestone is more vulnerable to chemical weathering than granite because limestone dissolves more easily in weak acids.
• Biological weathering happens when plant roots grow into cracks or burrowing animals disturb rock and soil, causing rock to break apart.
• Weathering weakens cliff faces and makes them more vulnerable to erosion and mass movement.
• Mass movement is the downhill movement of weathered material under the force of gravity.
• Heavy rainfall increases the risk of mass movement by saturating cliff material through runoff and throughflow.
• The type and speed of mass movement depend on slope angle, rock type, rock structure, water content, vegetation cover, climate and human activity.
• Rockfalls happen when fragments break away from a steep cliff face and fall rapidly, often after weathering or heavy rain has weakened the rock.
• Landslides happen when a mass of rock or soil suddenly slides downhill along a slip plane.
• Slumping is a rotational movement in which saturated material, often clay, moves downhill along a curved slip plane.
• Hydraulic action erodes the coast when waves force air and water into cracks, increasing pressure until rock breaks apart.
• Abrasion erodes the coast when rocks and sand carried by waves scrape and grind against the cliff.
• Attrition happens when pebbles carried by waves collide with each other, becoming smaller, smoother and rounder.
• Solution erodes the coast when acidic seawater dissolves soluble rocks such as limestone and chalk.
• Coastal material can be transported by traction, saltation, suspension and solution.
• Traction transports large pebbles and boulders by rolling them along the seabed.
• Saltation transports small pebbles and sand grains by bouncing them along the seabed.
• Suspension transports very fine sediment within the water.
• Longshore drift is the main process of sediment transportation along many coasts.
• Longshore drift happens when waves approach the shore at an angle, the swash moves sediment up the beach at that angle and the backwash returns sediment at right angles under gravity.
• Longshore drift moves sediment along the coast in a zig-zag pattern in the direction of the prevailing wind.
• Deposition happens when the sea loses energy and can no longer carry its load.
• Deposition is most likely in sheltered areas such as bays and estuaries where water movement is slower.
• Deposited sediment can build beaches in bays and create mudflats and salt marshes in sheltered estuaries, often behind spits.
• Geology shapes coastlines over time by controlling how quickly different rocks erode.
• Softer rocks such as sands and clays erode more easily than harder rocks and tend to form low, flatter coastal landscapes such as bays and beaches.
• Harder rocks erode more slowly than softer rocks and tend to form rugged coastal landscapes such as headlands.
• Hard rock coasts usually have high, steep cliffs with bare rock and boulders at the base.
• Soft rock coasts usually have lower, gentler cliff faces with smoother profiles, evidence of slumping, and little rock at the base.
• Geology shapes coastlines vertically by influencing cliff height and profile and horizontally by creating headlands and bays.
• Headlands and bays form where alternating bands of hard and soft rock lie perpendicular to the incoming waves.
• Softer rock erodes more rapidly to form an inlet that widens into a bay.
• More resistant rock remains projecting into the sea as a headland.
• Bays are often associated with beaches because they are more sheltered from wave energy than headlands.
• A headland usually projects into the sea, is longer than it is wide, and is made of resistant rock.
• A bay usually has a wide sea entrance, a roughly semi-circular shape, and land lower than the surrounding headlands.
• Cliffs are shaped by a combination of marine erosion and sub-aerial weathering.
• Soft rock tends to form sloping cliff faces, whereas hard rock tends to form steeper cliffs.
• A wave-cut platform is a wide, gently sloping rocky surface at the foot of a retreating cliff.
• Wave erosion between high and low tide levels cuts a wave-cut notch into the base of a cliff.
• Hydraulic action, abrasion and corrosion deepen the wave-cut notch until the cliff above becomes unstable.
• When the overhanging cliff collapses and the debris is removed by the sea, a wave-cut platform is left behind.
• Repeated undercutting and collapse cause the cliff line to retreat inland over time.
• Caves, arches, stacks and stumps commonly develop in coastal headlands where waves exploit lines of weakness.
• Wave refraction happens when waves slow in shallow water and bend so that their crests become more parallel to the coastline.
• Wave refraction concentrates erosion on the sides of a headland.
• Hydraulic action, abrasion and corrosion widen cracks in a headland to form caves.
• Continued erosion can enlarge a cave until it breaks through the headland to form an arch.
• Erosion at the base and weathering from above weaken an arch until its roof collapses.
• The collapse of an arch leaves an isolated pillar of rock called a stack.
• Further undercutting and weathering cause a stack to collapse and leave a stump.
• Beaches usually form in sheltered areas such as bays where constructive waves deposit sediment.
• Constructive waves build beaches because swash is stronger than backwash.
• Beaches are often widest in summer when calmer conditions favour deposition.
• Larger sediment is usually deposited higher up the beach by swash, while finer material is deposited lower down the beach and offshore in lower-energy water.
• Storm waves can throw large shingle above the normal high tide level to form a berm at the top of a beach.
• Sand dunes usually develop behind sandy beaches where strong onshore winds blow dry sand inland.
• Obstacles such as driftwood, pebbles or vegetation trap wind-blown sand and start the formation of embryo dunes.
• Sand dune ridges tend to form at right angles to the prevailing wind.
• Sand dunes migrate inland as wind moves sand from the seaward side to the leeward side.
• Vegetation stabilises sand dunes and drives succession from embryo dunes to mature dunes.
• Pioneer species on embryo dunes must tolerate salinity, drought, strong winds, burial by sand and changing sea levels.
• Embryo dunes are fragile, alkaline, low in soil content and usually reach only about 1 metre in height.
• Fore dunes develop when embryo dunes provide shelter, allowing plants such as marram grass to colonise and stabilise the sand with their roots.
• Organic matter from vegetation makes fore dunes more hospitable for later plant species, and fore dunes can reach about 5 metres in height.
• Yellow dunes become darker as humus builds up, still contain much marram grass, and usually do not exceed about 8 metres in height.
• Grey dunes are more stable than yellow dunes, have little exposed sand, support greater biodiversity, and contain more acidic and moist soil.
• Mature dunes are the oldest and most stable dunes, occur furthest inland, and can support climax vegetation and diverse fauna.
• A spit is a long ridge of sand or shingle that extends from the coast into the sea.
• Spits form when longshore drift transports sediment along the coast and deposition occurs where the coastline changes direction or at an estuary mouth.
• A spit cannot usually grow right across an estuary because river flow keeps the channel open.
• Changes in wind direction and currents can create a hooked end at the end of a spit.
• The sheltered water behind a spit encourages the deposition of silt, forming mudflats or salt marshes.
• A bar forms when a spit extends across a bay and joins two headlands.
• A bar can trap water behind it to create a lagoon.
• Offshore sandbars can also form when breaking waves deposit sediment away from the shoreline.
• Swanage Bay along the Dorset coast contains alternating bands of soft clay, limestone and chalk that have produced both erosional and depositional landforms.
• Durdle Door is a coastal arch on the Dorset coast formed when wave erosion widened a crack and cave in a limestone headland.
• Lulworth Cove formed where erosion broke through a resistant limestone band and then rapidly eroded the softer clay behind it, creating a small bay with a narrow entrance.
• Swanage lies between Studland Bay and Swanage Bay, which are associated with softer sandstone and clay.
• The Foreland is a chalk headland between Studland Bay and Swanage Bay.
• Old Harry is a stack formed from the erosion of the chalk headland at The Foreland.
• Old Harry's Wife is a stump formed after further erosion of the chalk headland at The Foreland.
• Chesil Beach is a pebble tombolo about 18 miles long formed by longshore drift and joining the Isle of Portland to the mainland.
• Swanage is a seaside town in Dorset on the south coast of England.
• Swanage lies in a sheltered bay with a broad sandy beach.
• Different rock types and geological structures around Swanage have created a range of contrasting coastal landforms.
• Headlands and bays around Swanage have formed where alternating bands of resistant hard rock and less resistant soft rock meet the sea.
• The coastline around Swanage includes a discordant section where alternating bands of hard chalk and softer clays and sands lie at right angles to the sea.
• The coastline around Swanage also includes a concordant section where limestone runs parallel to the sea and creates a relatively straight coastline.
• Poole Harbour, near Swanage, is a sheltered bay where deposition has formed two spits at the harbour mouth.
• Studland, near Swanage, contains lagoons, salt marshes and sand dunes.
• Old Harry is a stack formed by erosion on a chalk headland south of Studland Bay.
• Old Harry's Wife is a stump formed by further erosion of the same chalk headland south of Studland Bay.
• Swanage Bay is a bay with a sandy beach formed in softer rock known as Wealden clay.
• Coastal management aims to reduce the risks of coastal erosion and flooding for people, property and environments.
• Some stretches of coastline are not protected because the economic value of the land and assets at risk is lower than the cost of defence.
• Hard engineering uses artificial structures made from materials such as concrete, wood and rock to resist wave energy.
• Hard engineering schemes are expensive to build and usually require regular maintenance.
• Hard engineering can protect one place while increasing erosion or flood risk further along the coast by interrupting natural sediment movement.
• Hard engineering is most likely to be used where settlements or high-value infrastructure such as power stations are at risk.
• A sea wall is usually a curved concrete barrier that reflects wave energy back towards the sea.
• Sea walls are among the most effective defences against both erosion and flooding when they are high enough.
• Sea walls are expensive to build and maintain, can be damaged if the beach in front of them is lowered, can restrict beach access and can look visually intrusive.
• Groynes are timber, rock or steel barriers built at right angles to the shore to trap sediment moved by longshore drift.
• Groynes slow beach erosion and create wider beaches by increasing the amount of sand and shingle stored on the up-drift side.
• Groynes can increase erosion down-drift by starving other beaches of sediment, require maintenance if made of wood and can obstruct movement along the shore.
• Rock armour, also called rip-rap, consists of large boulders placed along the coast to absorb wave energy and protect cliffs or sea walls.
• Rock armour is cheaper than many other hard engineering methods and is effective at protecting the base of cliffs and sea walls.
• Rock armour can be eroded or dislodged during severe storms.
• Gabions are wire cages filled with rock, concrete or other material and are usually placed at the foot of cliffs or in front of defences.
• Gabions are one of the cheapest coastal defences, absorb wave energy and can be stacked to give extra support to cliffs or sea walls.
• Gabions are less effective than stronger hard engineering structures, and the wire cages can break unless they are secured well.
• Soft engineering works with natural coastal processes rather than trying to stop them completely.
• Soft engineering is usually cheaper than hard engineering, has less visual impact and is generally more sustainable.
• Soft engineering methods are often less immediately effective than hard engineering methods.
• Beach nourishment adds sand or shingle to a beach to replace sediment lost through erosion.
• Beach nourishment widens beaches so that more wave energy is absorbed before waves reach cliffs or defences.
• Beach nourishment must be repeated regularly, can disrupt sediment movement elsewhere and can damage fragile seabed ecosystems where material is dredged.
• Dune regeneration stabilises dunes by planting vegetation and managing access so that natural dune systems can recover.
• Dune regeneration reduces wind erosion, keeps the coastline looking natural and allows dunes to absorb wave energy and reduce erosion and flooding.
• Dune regeneration is relatively cheap but is difficult to use on large cliffed coastlines, often requires public access restrictions and can be damaged by storm waves.
• Beach reprofiling reshapes a beach by moving sediment from the lower beach to the upper beach to create a gentler profile.
• Managed retreat, also called coastal realignment, is the deliberate movement of people, land uses or defences away from areas at risk from coastal flooding or erosion.
• Managed retreat allows the sea to flood low-value land until it reaches higher ground or a new inland line of defence.
• Managed retreat avoids major construction costs, can create salt marsh habitats, can increase biodiversity and can reduce pressure on other sections of coastline inland or nearby.
• Managed retreat can cause the loss of homes and land, relocation costs, saltwater damage to existing ecosystems and disputes over compensation and high-value land.
• Coastal management often involves conflict because different stakeholders disagree about which stretches of coastline should be protected and which methods should be used.
• Many coastal managers use a range of methods based on the value of the land, communities and infrastructure being protected.
• Integrated Coastal Zone Management combines different management methods to balance physical conditions with the needs of different stakeholders.
• Coastal strategies often divide the coastline into coastal cells so that erosion and flood risks can be managed within linked sediment systems.
• Using coastal cells helps planners identify risks, target resources more effectively and compare the costs and benefits of different options.
• Shoreline Management Plans set out long-term approaches to reducing erosion and flood risk along stretches of coastline.
• Shoreline Management Plans aim to protect people, settlements, farmland and natural environments such as salt marshes.
• A hold-the-line policy maintains or strengthens defences so that the present shoreline position is preserved.
• Hold the line is usually the most expensive long-term option and mainly relies on hard engineering supported by some soft engineering.
• An advance-the-line policy builds new defences seaward of the existing coast and may involve land reclamation.
• Advance the line uses a mixture of hard and soft engineering to extend the current coastline.
• A managed realignment policy allows the shoreline to move naturally inland by removing or reducing defences.
• Managed realignment can create marshland that protects land further inland and new habitats, but it can also cause land loss, damage livelihoods and allow saltwater to affect ecosystems.
• A do-nothing policy allows the coast to erode and retreat without further investment in defence.
• A do-nothing policy is the cheapest option financially but is often the most controversial socially and politically.
• Decisions about shoreline management depend on the economic value of the land and property that could be protected.
• Decisions about shoreline management also depend on whether engineering solutions are physically possible on unstable cliffs or mobile landforms such as spits.
• The cultural and ecological importance of a place, including historic sites and areas of high biodiversity, can influence shoreline management decisions.
• Community pressure and the social importance of long-established settlements can also shape coastal management choices.
• Lyme Regis is a seaside town in Dorset on the south coast of England within the Jurassic Coast World Heritage Site.
• Lyme Regis is a named example of a coastal management scheme in the UK.
• Lyme Regis needed coastal management because the town was built on unstable cliffs exposed to destructive south-west waves.
• Coastal erosion and cliff instability at Lyme Regis breached the sea wall several times and damaged or destroyed properties.
• Phase 1 of the Lyme Regis scheme was completed in 1995 and included a new sea wall and promenade.
• Emergency work in 2003 and 2004 stabilised the cliffs at Lyme Regis by using rock nails, improving drainage and reprofiling the beach slope at a cost of £1.4 million.
• Phase 2 of the Lyme Regis scheme ran from 2005 to 2007 and cost £22 million.
• Phase 2 at Lyme Regis built new sea walls and promenades and created a wider sand and shingle beach to absorb wave energy and increase use of the shore.
• The shingle used in Phase 2 at Lyme Regis was dredged from the English Channel and the sand was imported from France.
• Phase 2 at Lyme Regis also extended rock armour at The Cobb to dissipate wave energy and help retain the new beach.
• The planned Phase 3 scheme west of The Cobb was not carried out because the cost was judged to outweigh the benefits.
• Phase 4 of the Lyme Regis scheme ran from 2013 to 2015 and cost £20 million.
• Phase 4 at Lyme Regis built a new 390 metre sea wall in front of the existing sea wall.
• Phase 4 at Lyme Regis used extensive nailing, piling and drainage to stabilise the cliffs and protect 480 homes.
• The new beaches at Lyme Regis have increased visitor numbers and helped seafront businesses to thrive.
• The new coastal defences at Lyme Regis have remained effective through recent stormy winters and have given better protection to the harbour, boat owners and fishermen.
• Increased tourism at Lyme Regis has created conflict because it has contributed to traffic congestion and littering.
• Some people argue that the new defences at Lyme Regis have spoiled the natural coastal landscape.
• Some people argue that the new sea wall at Lyme Regis interferes with natural coastal processes and may starve neighbouring beaches of sediment.
• Stabilising the cliffs at Lyme Regis may reduce the landslips that reveal important fossils.
• Abrasion is a type of coastal erosion in which rocks and pebbles carried by waves wear away cliffs and shorelines like sandpaper.
• Attrition is a coastal process in which rocks and pebbles carried by waves collide and break into smaller, smoother and rounder pieces.
• Backwash is the movement of water back down a beach after a wave has broken.
• Chemical weathering is the breakdown of rock by chemical reactions, often involving slightly acidic rainwater.
• Constructive waves have strong swash and weak backwash, so they deposit sediment and build up beaches.
• Destructive waves have weak swash and strong backwash, so they remove sediment and erode the coastline.
• Fetch is the distance that wind blows across open water and it influences the size and strength of waves.
• Freeze-thaw weathering is a mechanical process in which water enters cracks, freezes, expands and gradually breaks rock apart.
• Hydraulic action is coastal erosion caused by the force of waves compressing air and water into cracks in rock.
• Longshore drift is the transport of sediment along a coastline in a zigzag pattern caused by waves approaching the shore at an angle.
• Mass movement is the downhill movement of rock and soil under the force of gravity, including sliding, slumping and rockfalls.
• Saltation is a form of coastal transportation in which small pebbles and sand grains bounce along the seabed.
• Solution as an erosion process is the dissolving of soluble rock by acidic water.
• Solution as a transportation process is the movement of dissolved minerals within seawater.
• Soil creep is a very slow form of mass movement in which soil gradually moves downhill.
• Suspension is a form of coastal transportation in which very fine sediment is carried within the water.
• Swash is the movement of water up a beach after a wave breaks.
• Traction is a form of coastal transportation in which large pebbles and boulders are rolled along the seabed.
• Weathering is the breakdown of rock in situ by physical, chemical or biological processes.
• An arch is a natural opening through a headland formed when erosion breaks through from one side to the other.
• A bar is a depositional landform formed when a spit grows across a bay and joins two headlands.
• A bay is a curved and sheltered inlet between two headlands, often containing a beach.
• A beach is a depositional landform made of sand or shingle that is usually formed by constructive waves.
• A berm is a ridge of material at the top of a beach formed by strong waves depositing larger sediment.
• A cave is a hollow in a cliff or headland formed by erosion widening a crack or weakness in the rock.
• A cliff is a steep rock or earth face along the coast formed by erosion, weathering and mass movement.
• An embryo dune is the first stage of sand dune development, formed where wind-blown sand collects around an obstacle.
• A fore dune is a larger sand dune behind the embryo dune that has been stabilised by vegetation such as marram grass.
• A grey dune is an older, more stable dune with little exposed sand, richer soils and greater biodiversity.
• A headland is a projection of resistant rock that juts out into the sea.
• A mature dune is the oldest and most stable stage of a sand dune system, usually found furthest inland.
• A sand dune is a mound or ridge of wind-blown sand that is stabilised by vegetation.
• A spit is a narrow ridge of sand or shingle that extends out from the coast because of longshore drift.
• A stack is an isolated pillar of rock formed when the roof of an arch collapses.
• A stump is the low eroded remnant of a former stack.
• A tombolo is a ridge of sand or shingle that connects an island to the mainland.
• A wave-cut notch is an indentation at the base of a cliff formed by repeated wave erosion.
• A wave-cut platform is a flat rocky surface left behind as a cliff retreats through repeated undercutting and collapse.
• A yellow dune is a developing dune in which organic matter is beginning to build up and darken the sand.
• Advance the line is a coastal management policy in which new defences are built seaward of the existing coastline.
• Beach nourishment is a soft engineering method in which sand or shingle is added to a beach to absorb wave energy and reduce erosion.
• Beach reprofiling is a soft engineering method in which sediment is moved from the lower beach to the upper beach to change the beach profile.
• Gabions are wire cages filled with rocks that are placed at the foot of cliffs or defences to absorb wave energy.
• Groynes are barriers built at right angles to the shore to trap sediment moved by longshore drift.
• Hard engineering is the use of artificial structures such as sea walls and groynes to control coastal processes.
• Hold the line is a coastal management policy in which existing defences are maintained or strengthened to keep the shoreline in its current position.
• Integrated Coastal Zone Management is a coastal management approach that combines different methods to manage coastlines sustainably.
• Managed retreat is a coastal management strategy in which the sea is allowed to flood inland in a controlled way to reduce pressure on other areas.
• Offshore barriers are structures built in the sea to reduce wave energy before waves reach the coast.
• A revetment is a sloping wooden or concrete barrier built to absorb wave energy and protect the coast.
• Rip-rap, also called rock armour, is a line of large boulders placed along the shore to absorb wave energy.
• A sea wall is a concrete or stone wall built along the coast to reflect or absorb wave energy.
• A Shoreline Management Plan is a long-term plan that sets out how a stretch of coastline will be managed.
• Soft engineering is the use of coastal management methods that work with natural processes rather than resisting them completely.

• Identify whether a wave is constructive or destructive from its swash, backwash, height, wavelength, frequency and effect on sediment.
• Explain how fetch, wind strength and wind duration affect wave size and coastal energy.
• Distinguish between weathering, erosion, mass movement, transportation and deposition in a coastal process description.
• Select the most likely type of weathering, erosion, transportation or mass movement operating in a described coastal situation.
• Explain how geology and rock resistance produce contrasting headlands, bays, cliff profiles and wave-cut platforms.
• Sequence the formation of a wave-cut platform from notch development through collapse and cliff retreat.
• Sequence the formation of a cave, arch, stack and stump from lines of weakness in a headland.
• Explain how wave refraction increases erosion on headlands and encourages deposition in bays.
• Explain the formation of a beach, spit, bar or sand dune by linking transportation and deposition processes.
• Interpret photographs, maps or diagrams to identify erosional and depositional coastal landforms.
• Justify the identification of a coastal landform by referring to shape, sediment, geology and wave exposure.
• Apply knowledge of Swanage and the Dorset coast to explain how rock structure and resistance create contrasting coastal landforms.
• Compare hard engineering, soft engineering and managed retreat in terms of cost, effectiveness, sustainability and environmental impact.
• Select an appropriate coastal management strategy for a named place using evidence about land value, erosion risk and physical conditions.
• Evaluate the costs and benefits of sea walls, groynes, rock armour, gabions, beach nourishment, reprofiling and dune regeneration for a specific coastline.
• Explain why coastal management creates conflict between different stakeholders and locations along the same sediment cell.
• Assess the overall success of a named UK coastal management scheme by weighing its reasons, methods, effects and conflicts.