term 1 physical geography (costs) (types of waves (high energy waves -…
term 1 physical geography (costs)
costal management strategies : groynes, sea wall, rip rap, beach nourishment, breakwater.
gold coast (broad beech)
costal management - they use beach nourishment and they also have the great barrier reef as a barrier.
types of waves
high energy waves - (storm waves) produced by strong winds, when breaks onto steep sloping beaches producing plunging waves, these are destructive.
low energy waves - if the wind dies the wave will still travel until they hit a coastline. the hight of the wave decreases and the wave length increases, these are genital waves
destructive waves - these waves remove the sediment from the beach, they have a short wavelength and a high wave height also with a hight frequency. the swash is weak and the backwash is strong.
constructive waves - these waves add sediment to the coastline as their swash is stronger than the backwash. they have a long wavelength and a low frequency
different waves breaks
spilling waves -genital beech gradients and steep waves. the peaks of the waves become unbalanced and spill forward onto the beach.
plunging waves - steep breaker, crashing down onto the beach, they have tall wave height, short wavelength and high frequency.
surging breakers - steep beaches, the waves slide so don't officially break as they surge up the beach.
sub arial processes
salt weathering - the sodium and the magnesium compounds expand the cracks in the rock, increasing the rate of erosion
freeze thaw weathering - the water freezes in the cracks in the rocks, when it freezes the crack in the rock expands then happens again when the water melts and freezes again.
biological weathering - carried out by and animal / plant that exerts stress or damage onto the rock.
chemical weathering - the chemical reactions of chemicals of acid rein and the rocks or plants that will effect the rock.
slaking - when the rocks disintegrate when they touch the water
hydraulic action / erosion - wave induced pressure breaking down materials like rock.
abrasion - materials scraping the beeches / cliffs, chipping away at the surface.
solution - the dissolved materials rubbing against the surface.
attrition - the materials, when moving breaking down, does not affect the coast.
cavitation - air is forced into gaps in the cliff and then expands under pressure.
transportation - movement of the eroded materials.
suspension - sediment suspended in the water, you can see the materials
traction - the materials rolling along the bed.
saltation - the materials bouncing along the bed.
deposition - the materials dropping from the movement of the water.
sea level change is the change in depth of the sea in relation to land.
factors affecting the sea level
the air pressure
types of reef
fringe reefs - these are close to shore reefs that are shallow broad and sand floored. they could be protected by a barrier reef so suited to low energy waves.
barrier reefs - grow great distances from the shore that fringe reefs. these reefs are broader than fringe reefs, are older and more continuous.
atoll reefs - rise from submerged volcanic foundation and often support small islands of wave-borne.