Coastal Landscapes

1. Coastal Landscapes Higher Geography Physical Environments: Lithosphere

5. Topic Outline • Name and explain the erosion processes at work. • Explain the formation of the following erosional landforms with the aid of a diagram and named e.g’s: Cliffs, Wave-cut platforms, Caves, Arches, Stacks, Stumps, Geos. • Explain with the aid of a diagram, the process of longshore drift. • Explain the formation of the following features of deposition with the aid of a diagram and named e.g’s: Beaches (note there are various types), Spits, Tombolos, Sandbars, Sand dunes & Salt Marshes. • Identify coastal features on an O.S map.

6. Aims of the lesson • To learn about the types of wave affecting coastal landscapes. • To learn how to name and describe the processes of coastal erosion. • To learn how to describe the formation of headlands and bays with reference to a named example.

7. Swash & Backwash

8. Constructive Waves Flat and low in height. Its has a stronger swash than backwash. This means that it is responsible for depositing material on the coastline.

9. Destructive Waves Steep and high. The swash in this wave is weaker than the backwash. This means that material is removed from the beach leading to erosion.

10. Coastal Erosion Processes results from large waves hurling beach /eroded material against a cliff. Hydraulic pressure is when waves cause rocks and pebbles on the beach to bump into each other and wear down in size. Abrasion is the sheer force of the waves especially when they trap and compress air in cracks and holes in a cliff. Corrosion is when certain types of rock types in a cliff are actually slowly dissolved by the seawater. Attrition

11. Rate of Erosion Waves - Strength, frequency, height Weather - frequency of storm conditions Geology of the coastline

12. Headlands & Bays Take a copy of the diagram below in your notes. Arrange the statements in order to describe the formation of headlands and bays.

13. The softer rocks therefore erode backwards faster to form sheltered bays (which may have beaches), e.g. sandstone and clay and which meet the coast at right angles. Headlands and bays are formed due to differential erosion, whereas the harder rock areas jut out into the sea to form exposed headlands. An excellent example of this landform is Lulworth Cove on the Dorset coastline. Clay is a softer rock than the sandstone so is eroded more quickly. where rocks along the coastline are formed in alternating bands of different rock types

14. Lulworth Cove

15. Summary So far we have… • learnt about the types of wave affecting coastal landscapes. • learnt how to name and describe the processes of coastal erosion. • learnt how to describe the formation of headlands and bays with reference to a named example.

16. On the Wall! Each table has been given post-its. Get your answers stuck to the questions posted around the room First group wins!

17. On the Wall • Name the type of wave that leads to dominant erosion. • What is swash? • How long is the coastline of the UK in kilometres? Closest guess wins. • Name the 4 processes of coastal erosion. • Give a factor that will affect the rate of coastal erosion. • Draw a diagram of headlands & bays with a named example.

18. Headlands & Bays

19. Aims of the lesson • To learn how to describe the formation of a cliff and wave cut platform. • To learn named examples of these features.

20. Cliffs & Wave Cut Platforms This clip will give you an introduction to cliffs, wave cut platforms and other coastal erosion features. BBC Learning Zone - Cliffs & Wave Cut Platforms

21. Cliffs & Wave Cut Platforms Cliffs form where high land reaches the sea. Weaknesses (joints and faultlines) in the rock are progressively undercut by wave erosion. This forms what is called a wave-cut notch. This notch is enlarged and eventually the overhanging rock collapses. As this processes is repeated, the cliff retreats, exposing a gently sloping rock surface called a wave cut platform.

22. Wave Cut Platform: South Glamorgan, Wales

26. Hard Rock Cliffs Hard rocks are more resistant than soft ones, and will form steep cliff faces. Made up of rocks like basalt and granite. Named Example: Caithness

27. Soft Rock Cliffs These cliffs often erode rapidly. In these cliffs, sub-aerial processes can contribute more to erosion than marine processes, leading to mass movements such as sliding, slumping and falls. Named Example: FairlightCove, Hastings

28. Describe the formation of a cliff and a wave cut platform.

29. Summary So far we have… • Learnt the formation of a cliff and a wave cut platform with reference to a named example.

30. Match Up Diagram

31. Aims of the lesson • To learn how to describe the formation of caves, arches and stacks. • To learn named examples of these features.

32. Green Arch of Wales

34. Durdle Door, Dorset

36. Caves, Arches, Stacks & Stumps

37. Caves, Arches, Stacks & Stumps Read p123 & 124 of the Higher Textbook. Using the information contained on those pages, you are going to create a model that shows the formation of these landforms. Use the labels on the cards to annotate your model. Your model must include: • A crack • A cave • An arch • A stack • A stump • A blowhole

40. Fieldsketch On plain A4 paper, create a simple fieldsketch of your model with all of the appropriate annotations. Use a ruler and pencil.

42. Homework With the aid of annotated diagrams, explain the formation of a stack. Tips: • Ensure you include fully annotated diagrams • You will need to refer to caves and arches also. • You must include the processes that form the features e.g. for stack, hydraulic action, attrition, corrasion.

43. Homework With the aid of annotated diagrams, explain the formation of a stack. Tips: • Ensure you include fully annotated diagrams • You will need to refer to caves and arches also. • You must include the processes that form the features e.g. for stack, hydraulic action, attrition, corrasion.

44. Summary So far we have… • learnt how to describe the formation of caves, arches and stacks. • learnt named examples of these features.

45. True or False • A constructive wave has a stronger swash than backwash. • Hydraulic action is the impact of rocks and other material on the cliff face. • Our named example of a wave cut platform is Durdle Door. • Hard rock cliffs are more vulnerable to weathering and often slump rather than collapsing into the sea in blocks. • The formation of headlands and bays is a result of a process called differential erosion. • A blowhole is a made up landform. • Our named example of an arch is in South Glamorgan, Wales.

46. Aims of the lesson • To be able to describe the process of longshore drift in coastal environments with reference to a diagram.

47. Longshore Drift Waves often approach a beach at an angle. The swash carries material up the beach at an angle and then the returning backwash drags much of the material back down. Over time, the material is moved along the shore in the direction of the prevailing wind. This processes of transportation is called longshore drift.

48. Direction of movement Backwash is always at right angles to the beach Swash Backwash This movement of sediment along the coastline is called longshore drift.

49. Longshore Drift Poster Activity Equipment Set of cards & arrows Scissors Glue A4 coloured paper Pen/pencils Each of you is going to create a poster to demonstrate the process of coastal transportation. You must use all of the equipment provided. Use p128 of the Higher Textbook to help you.

50. Swash Arrows