Coastal erosion is influenced by four main processes: corrosion from saltwater, attrition from pebbles hitting cliffs and other materials, abrasion from waves throwing stones that smooth materials, and hydraulic action from water forcing into cracks and splitting rocks apart. These processes create landforms like headlands and bays, wave-cut platforms and notches, beaches, spits, and bars. The geology of the coast determines how resistant the rocks are to erosion - more resistant rocks like chalk erode more slowly than less resistant rocks like clay and limestone. Waves coming directly onto shore are more destructive than waves hitting the coast at an angle, as destructive waves have more energy to erode the land.

1. Exam Q
• Including keywords where possible, describe
and explain how erosion can influence the
coast. You may use a diagram.
[3marks]

2. Recap: What are the 4 Types of
coastal erosion?

3. Erosion is……. the wearing away of
materials by one of four processes:
 Corrosion = chemical reactions of salt water
weakening rocks like an acid
 Attrition = Pebbles hitting into each other or into
cliffs making rocks break and get smaller and rounder
 Abrasion = ‘sand paper’ effect. Waves throwing small
stones and pebbles at cliffs and beaches to smooth the
material
 Hydraulic Action = Power of the water forcing its way
into cracks and weaknesses in rocks, splitting apart

4. Recap : landforms

5. The main landforms created by erosion are…

6. Headlands and Bays

8. Wave cut notches and platforms

9. Wave-cut platform –
Burgh Island, Devon
Wave cut platform
Southerndown,
South Wales.

11. Beaches develop where the supply of sediment exceeds loss
through backwash and longshore drift.
Beaches are usually distinguished as either …
Shingle
or Sand
Shingle beaches are free draining so there is little backwash of material to sea.
As a consequence, they are usually steeper.

12. How was this landform created?

13. Spits and Bars
Where there is a change in the coastline e.g. a headland or an
estuary mouth, longshore drift may continue to deposit
sediments into the sea forming a spit.

14. Local currents and changes in wind direction may curve
the end of the spit landwards creating a hooked tip.
The presence of the estuary discharging river water into
the sea prevents the spit from developing into a bar.
Such a feature is known as a recurved spit
wind

15. Exam Q
• How does geology influence the speed of
erosion at the coast?
[2marks]

16. The geology of the coast
affects how much it is
eroded.
More resistant rocks
(e.g. chalk) erode more
slowly than less
resistant rocks (e.g. clay,
limestone)
This gives us BAYS
And HEADLANDS

17. The Jurassic
Coast
• The Jurassic Coast is a section of coastline in
Southern England that shows geology over
millions of years.
• The coastline first began forming 250million
years ago
• Dorset shows the geology of the Jurassic
period, between 200-140million years ago

19. What about waves?

20. If you were a wave, and you wanted to grow big and strong so you
could knock the UK’s block off, which direction would you come from?
Why?

21. Waves
• There are two main types of waves:
• Constructive vs Destructive

22. Exam Q
Describe and explain how constructive and
destructive waves work. Use keywords or
examples where possible. [4marks]

23. How do waves influence
landforms?
Longshore drift

24. Longshore drift…
http://www.youtube.com/watch?v=29o5ntbxjJs

25. Long-shore drift (LSD)

26. Exam Q:
“With the use of a diagram, explain the process
and effects of longshore drift, and how it can be
managed”
[6marks]

27. Reminder about Grid References

28. Constructive or Destructive coastline?
What evidence from the map?