1. 4. Coastal Erosion

2. Coastal erosion
When a wave crashes down a beach or smashes against a cliff, it carries out the process of erosion.
There are several processes of coastal erosion:
Hydraulic power
Corrasion
Abrasion
Solution
Attrition

3. 1. Hydraulic Power Also known as hydraulic action or wave pounding.
The sheer power of the waves smash into the cliff. Trapped air is blasted into holes and cracks in the rock, eventually causing the rock to break apart. The explosive force of trapped air operating in a crack is called cavitation.

4. How much energy is that per m² per day? _______tonnes
Did you know?
As storm waves crash into cliffs, they create incredible pressures on the air inside joints and caves at 30 tonnes per square metre per wave, and remember there are 22,000 waves per day at Land’s End – that’s a lot of wave energy!
How much energy is that per m² per day? _______tonnes

5. Rock type
Soft rock: soft clays will be eroded quickly. Turns the sea brown and muddy e.g. Holderness. Over 1 metre per year!
Hard rocks: granite are eroded slowly e.g. Land’s End, Cornwall. 0.1m each century!

6. 2. Corrasion
This involves fragments of rock being picked up and hurled by the sea at a cliff. The rocks act like erosive tools by scraping and gouging the rock.

7. 3. Abrasion
This is the ‘sandpapering’ effect of pebbles grinding over a rocky platform, often causing it to become smooth.
Label the evidence for wave abrasion.

8. 4. Solution Also known as corrosion.
Some rocks are vulnerable to being dissolved by seawater. This is particularly true of limestone and chalk, which form cliffs in many parts of the UK.
Sea water itself is a corrosive agent which operates all year round.

9. 5. Attrition
This is where rock fragments carried by the sea knock against one another, causing them to become smaller and more rounded.
As the tide comes in, waves will move the individual particles and clatter them together in a banging motion, especially violently in storms.

10. What is the effect of wave attrition upon the beach material?

11. Wave Scouring
How was this wave cut notch created?

12. Cliff Line Retreat
How does a cliff line retreat?

14. Over to you…
You must learn these key terms and understand the difference between them.
Create a poster showing all 5 processes of erosion for you to have as a summary.
Use the rocks to help you!