AQA GCSE Geography: Coasts

Wind blowing over the sea. Friction with water surface causes ripples that develop into waves. The longer the fetch the more powerful the wave.

The distance the wind blows across the water

The wave breaks onto the beach and moves up it

Water rolling back from the beach due to gravity

A wind coming from the predominant direction

Long fetch with weak wind, low wave in proportion to length. Strong swash, weak backwash (soaks into sand/slowly drains away)

Usually found in summer because of the weaker winds

Strong prevailing wind with a long fetch. Causes erosion. Tall breaker, weak swash, strong backwash.

It breaks downwards with a great force

In the winter (strong winds) and near oceans because of the strong prevailing wind, e.g Cornwall as it is close to the Atlantic

1. Hydraulic Action (pop!) 2. Abrasion 3. Attrition 4. Solution

1. Traction 2.Saltation 3. Suspension 4. Solution

Biological (trees growing), Chemical (limestone dissolving in water), Mechanical (freeze thaw)

The downhill movement of weathered material due to the force of gravity

1. Rock Fall 2. Mudflow 3. Landslide 4. Rotational Slip

An avalanche of loose rocks, made worse by mechanical weathering (freeze thaw). An example of this was in Burton Bradstock, Dorset Coast in August 2016

A fluid or hardened stream or avalanche of mud often made worse by biological weathering. An example of this was in Stehekin, Washington in 2013.

Blocks of rock slide downhill made worse by biological weathering. An example of this was in Hells Mouth, Cornwall in 2016.

Slump of saturated soil on a weak surface. An example of this is the Holbeck Hall landslide in Scarborough

When sediment moves across the beach. First onto it by swash (in the direction of the prevailling wind), when it comes back in backwash it goes at a right angle to the beach. This repeats.

a narrow piece of land that projects from a coastline into the sea.

a broad inlet of the sea where the land curves inwards.

It starts with a cliff face facing the sea that has alternate layers of soft rock (clay) and hard rock (sandstone, chalk, limestone). As the waves crash into the cliff face, erosion occurs. Due to the soft rock being less resistant, it erodes quickly, causing the hard rock to be left jutting outwards.

It starts with a cliff face facing the sea that has alternate layers of soft rock (clay) and hard rock (sandstone, chalk, limestone). As the waves crash into the cliff face, erosion occurs. Due to the soft rock being less resistant, it erodes quickly, causing the hard rock to be left jutting outwards. This leaves bays that form in the soft rocks that curve inwards.

Narrow flat area found at the edge of a sea cliff

Long narrow ridges of sand and shingle which is projected into the sea from the coastline.

1. L.S.D carries material across the coastline 2. This build of material creates an extension of the land 3. Spit grows out into sea 4. Spit becomes exposed to changes in wind and wave direction causing the spit to create a recurved end 5. Salt marshes form behind the spit 6. If the spit is growing across an estuary the length will be restricted due to floculation

Spurn Head, Humber, Holderness Coast

A ridge of sand and shingle joining the mainland to an island

The spit continues to grow until it connects the mainland and an island (like a bridge)

Chesil Beach - which joins the South Dorset coast to the Isle of Portland.

A ridge of sand and shingle which has joined two headlands, cutting off a bay

1. A spit grows the whole way across a bay 2. A lagoon forms in the bay and as there is low energy a salt marsh is created as there is lots of deposition

Slapton Sands - Devon.

1. The headland is eroded by the force of the waves 2. This creates a fault in the rock 3. This forms a cave 3. is eroded through, arch 4. Arch head falls, stack 4. Stack is undercut, stump

a natural underground chamber in a hillside or cliff, formed due to erosion of a headland

e.g old harry

e.g old harry's wife

hard engineering is controlled disruption of natural processes by using man-made structures, e.g groynes, sea walls, rock armour

Can prevent lsd (groynes), protect the base of the cliff (sea wall), absorb energy of waves and allow build up of beach (rock armour)

Ugly, expensive, unsustainable, lots of maintenance needed

soft engineering is the use of ecological principles and practices to reduce erosion, working with the environment, e.g beach nourishment, managed retreat

don't disturb the natural environment, cheap, natural

have to compensate farmers (managed retreat), constant maintenance (beach nourishment)

As temperatures rise (due to global warming), the sea absorbs heat from the atmosphere causing it to expand and sea levels rise.

Top layer of water is getting warmer so ice caps are melting, this causes sea level rise

SOCIAL: death toll, water supplies (too much salt), loss of housing, loss of jobs ECON: decrease of land value, loss of tourism, damaged farm land ENVIRON: adaptation to ecosystems, increased coastal erosion

Maldives - population of 300,000, made up of 1190 islands (199 are inhabited). Flat land (1.5m above sea level is average island height) scientists think it will be completely submerged in 50 to 100 years. Could disrupt their fish export which is their largest export