physical landscapes in the uk - coasts

relief

* describes the height, steepness and shape of the landscape
* determined by geology

how waves form

* by wind blowing over the sea
* friction with the surface with the surface of the water causes ripples that develop into waves
* tsunamis form when earthquakes or volcanic eruptions shake the seabed

constructive waves

* formed by storms often hundreds of kilometres away
* common in summer
* low waves with wave crest far apart
* gently sloping wave front
* breaking waves push large amounts of sand and pebbles up the beach
* gently sloping beach

destructive waves

* formed by local storms close to coast
* common in winter
* waves close together
* waves become high with steep wave front
* breaking waves plunge down onto beach with little forward swash
* strong backwash erodes sand and pebbles and can destroy the beach
* steep beach

3 types of weathering

* mechanical - freeze thaw
* chemical - carbonation
* biological - plant roots

4 types of mass movement

* rockfall - rock breaks away often due to freeze thaw
* landslide - blocks of rock slide downhill
* mudflow - saturated soil and weak rock flows downhill
* rotational slip - slump of saturated soil and weak rock along a curved surface

coastal erosion

* solution - dissolving of soluble chemicals in rock
* corrasion - rock fragments picked up by the sea are thrown at cliff
* abrasion - sandpapering effect of pebbles
* attrition - rock fragments carried by sea knock against each other becoming smaller
* hydraulic power - power of waves hit a cliff

sediment transportation

* solution - dissolved chemicals
* suspension - particles suspended within water
* traction - large pebbles rolled along seabed
* saltation - bouncing of particles too heave to be suspended

longshore drift

* waves approach at an angle
* sediment moves along coast in a zig zag pattern
* direction of approaching waved driven by prevailing wind

coastal erosion landform - headlands and bays

* tougher, resistant bands of rock are eroded to form headlands
* weaker rocks eroded more easily to form bays

coastal erosion landform - caves, arches and stacks

* lines of weakness vulnerable to erosion
* abrasion and hydraulic action form a cave
* erosion lead to 2 back to back caves forming an arch
* arch eventually collapses from erosion and weathering
* leaves isolated stack
* stack eroded and collapses leaving a stump

coastal erosion landform - cliffs and wave cut platforms

* when waves break against cliff erosion will form a wave cut notch
* over time notch deepens undercutting cliff
* overlying cliff collapses
* repetition of this so cliff retreats
* leaves a wave cut platform

coastal deposition landforms - beaches

* deposits of sand and shingle
* found in bays and created by constructive waves
* along high energy coasts sand is washed away

coastal deposition landform - spits and bars

* longshore drift transports sand along coast
* change in shape of coastline
* spit grows from the land out into the sea
* spit exposed to changes in wind and wave directiob cause it to curve
* saltmarsh forms in sheltered water behind the spit as river mud deposits build up
* bar is spit across a bay