Landforms change over time through erosion. Cracks and weaknesses in resistant rock are widened by hydraulic action and air, forming wave-cut notches and caves. Cliffs made of resistant rock like chalk steeply face coastlines. As cliffs collapse, wave-cut platforms of smooth, eroded rock are left behind on beaches. This process of cliff retreat and wave-cut platform formation is demonstrated in a diagram. Students are asked to identify specific landforms like headlands, bays, arches, and stacks on a map of the south coast.

1. Describe how a landform may
change over time
It is important to know not just what landforms are
made but how they are made.
Model Answer
Even in resistant rock there are cracks and
weaknesses. The process of hydraulic action
forces air into these cracks which causes them
to widen into a wave cut notch. Over time this
forms a cave.

2. Cliffs are steep rock faces along the coastline, they form
along coastlines with resistant harder rocks such as chalk

3. Wave-cut platforms are rocky ledges on the beach left behind after a cliff
collapses. They become smooth over time with erosion.

4. Last line of Defence
http://www.ifever.org.uk/camera/
Start from 5 mins in
How far do you think the flags will erode?

5. This diagram shows how a cliff retreats and
wave cut platforms are made.

6. Identifying Landforms
The exam board requires you to be able to
interpret maps. Look at your map of the
south coast on the next slide. Can you
identify the following things?
• A headland
• A bay
• Two arches
• Two stacks/stumps