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Wave Action (Wave Type (Wind Strength (Pressure Gradient Forces,
Wind…
Transportation
Rivers pick up and carry material as they flow downstream.
The four different river transport processes
Solution - minerals are dissolved in the water and carried along in solution.
Suspension - fine light material is carried along in the water.
Saltation - small pebbles and stones are bounced along the river bed.
Traction - large boulders and rocks are rolled along the river bed.
Deposition
When the sea loses energy, it drops: the load which is the sand, the rock particles and pebbles it has been carrying. This is called deposition. Deposition happens when the swash is stronger than the backwash and is to do with constructive waves.
Deposition is likely to occur when:
waves enter an area of shallow water.
waves enter a covered area, eg a cove or bay.
there is a good supply of material.
Erosion
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Hydraulic Action: the force of the river against the banks can cause air to be trapped in cracks and crevices. The pressure weakens the banks and gradually wears it away.
Longshore Drift:the movement of material along a coast by waves which approach at an angle to the shore but recede directly away from it.
Attrition: ocks being carried by the river smash together and break into smaller, smoother and rounder particles.
Wave Type
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Wind Direction
The main 3 factors that effect wind direction and speed are: the pressure-gradient force, the Coriolis force and friction. These factors working together cause the wind to go in different directions and at different speeds.
Wind Strength
Pressure Gradient Forces,
Wind ultimately comes from temperature differences because temperature differences lead to air pressure differences, and air pressure creates convection currents, which create wind.
The Coriolis Effect:The Coriolis effect is like being on a merry-go-round. Imagine that you are on one side and your friend is directly across from you on the other. If you were to throw a ball to your friend while the merry-go-round was not spinning, it would go straight to them. This is our one-cell circulation pattern on a non-rotating Earth.
Constructive:
They are created in calm weather and are less powerful than destructive waves. They break on the shore and deposit material, building up beaches. They have a swash that is stronger than the backwash
Destructive:
They are created from big, strong waves when the wind is powerful and has been blowing for a long time. They occur when wave energy is high and the wave has travelled over a long fetch. They tend to erode the coast. They have a stronger backwash than swash.