Coasts as Natural Systems (AQA AS Geography): Exam Questions

Erosion occurs at the base of a cliff $\to$ a wave-cut platform begins to form $\to$ erosion extends the platform $\to$ waves have further to travel and lose energy $\to$ erosion decreases.

Vegetation begins to grow in sediments of saltmarshes $\to$ vegetation traps more sediment $\to$ height of the marsh increases $\to$length of time inundated by the sea reduces $\to$vegetation growth increases.

Storms erode sediment from a beach $\to$ sediment deposited as offshore bars $\to$ waves break earlier $\to$ erosion reduces $\to$ after the storm, waves return sediment to the beach.

Waves erode the base of a cliff $\to$ undercutting leaves the cliff unsupported $\to$ cliff collapses leaving debris at the base $\to$ cliff is protected from powerful waves $\to$ rates of erosion are reduced.

Changes in a system amplify, or speed up, the impacts of an initial action.

Changes in a system decrease, or slow down, the impacts of an initial action.

When there is a balance between the inputs and outputs of a system.

When there is a transfer of energy beyond the boundary of the system.