1. Lesson 6 Why do cliffs collapse?
Coasts
Lesson 6 Why do cliffs collapse?

2. Why do Cliffs Collapse?
Your objectives in this lesson:
Investigate the causes and effects of cliffs collapsing.
Explain that weathering, rain and wave erosion combine to cause cliffs to collapse.
Describe what happened when a cliff top hotel fell into the sea.
Explain why the cliff might have collapsed
Combine this information to write a newspaper article that describes and explains the event.

3. Mini white board investigation
Work in pairs…
Watch the video clips and study the images.
Follow the instructions.
As a pair think up the answers to the questions or write down questions that you ask.

4. What is happening to the cliff in this video?
2 mins
What type of rocks make up the cliff that collapsed?
Are they hard or soft?
What factors caused it to collapse?

5. What factors make coastal erosion worse?
1 min
What could make a cliff more likely to collapse?

6. Sometimes it is a spectacular event!

7. In one night...
5 June 1993

8. What happened? Read page 16 of geog 2 together.
Objective 1
What happened?
Read page 16 of geog 2 together.
You will use this later to write a newspaper report of the disaster.

9. Weathering Rain Wave Erosion
Objective 2 Understand that weathering, rain and wave erosion combine to cause cliffs to collapse.
Weathering
Rain
Wave Erosion

10. In your Exercise books …
Start a new clear page.
Title: Why do Cliffs Collapse
You are going to complete a webdiagarm on a worksheet to explain why cliff collapse
Cliff Collapse

11. Weathering
Weathering attacks the _____ of the cliff
C______________ weathering: ______ soaks in and ____________ minerals
Freeze- thaw: In winter water __________ in the cracks making them _________.
Cliff Collapse
Wave Erosion
Waves attack the _______ of the
cliff through H____________
Action, A___________,
S____________ and Attrition.
Rain
Rain ________ into the cracks. It makes
______ cliffs very s_______.
The clay can just slide away.
Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

12. Weathering Attacks the top of the cliff in two ways
Remember science…
Attacks the top of the cliff in two ways
Chemical Weathering
Freeze Thaw Weathering

13. Freeze Thaw
Water trickles into cracks.In icy weather it freezes, forcing the cracks wider until the rock breaks up.
Chemical
Remember Science?
Water reacts with Carbon dioxide in the air. The water becomes slightly acidic. (Carbonic acid). This dissolves the rock.

14. Attacks the top of cliff
Weathering
Attacks the top of cliff
Chemical
Freeze Thaw
Now add an explanation to your web diagram of how weathering weakens the cliff

15. Now complete this section of your web diagram.
Weathering
Weathering attacks the _____ of the cliff
C______________ weathering: ______ soaks in and ____________ minerals
Freeze- thaw: In winter water __________ in the cracks making them _________.
Cliff Collapse
Now complete this section of your web diagram.
Wave Erosion
Waves attack the _______ of the
cliff through H____________
Action, A___________,
S____________ and Attrition.
Rain
Rain ________ into the cracks. It makes
______ cliffs very s_______.
The clay can just slide away.
Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

16. Weathering Rain Wave Erosion
Objective 2 Understand that weathering, rain and wave erosion combine to cause cliffs to collapse.
Weathering
Rain
Wave Erosion

17. Rain Rain soaks into the cracks
The more water the cliff soaks up the weaker it is.
The water makes soft Clay cliff very weak and slippery.
The clay can just slide away!
Now add an explanation to your web diagram of how rain weakens the cliff

18. Now complete this section of your web diagram.
Weathering
Weathering attacks the _____ of the cliff
C______________ weathering: ______ soaks in and ____________ minerals
Freeze- thaw: In winter water __________ in the cracks making them _________.
Now complete this section of your web diagram.
Cliff Collapse
Wave Erosion
Waves attack the _______ of the
cliff through H____________
Action, A___________,
S____________ and Attrition.
Rain
Rain ________ into the cracks. It makes
______ cliffs very s_______.
The clay can just slide away.
Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

19. Weathering Rain Wave Erosion
Objective 2 Understand that weathering, rain and wave erosion combine to cause cliffs to collapse.
Weathering
Rain
Wave Erosion

20. Wave Erosion Waves attack the cliff. They erode it by:
Hydraulic Action
Abrasion
Solution
Attrition
Now add an explanation to your web diagram of how Wave Erosion weakens the cliff

21. Now complete this section of your web diagram.
Weathering
Weathering attacks the _____ of the cliff
C______________ weathering: ______ soaks in and ____________ minerals
Freeze- thaw: In winter water __________ in the cracks making them _________.
Now complete this section of your web diagram.
Cliff Collapse
Wave Erosion
Waves attack the _______ of the
cliff through H____________
Action, A___________,
S____________ and Attrition.
Rain
Rain ________ into the cracks. It makes
______ cliffs very s_______.
The clay can just slide away.
Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

22. Weathering attacks the top of the cliff.
Chemical weathering : rain soaks in and dissolves minerals
Freeze- thaw: In winter water freezes in the cracks making them larger
How did you get on?
Cliff Collapse
Rain
Rain soaks into the cracks. It makes clay cliffs very slippery. The clay can just slide away.
Wave Erosion
Waves attack the base of the cliff through Hydraulic Action, Abrasion, Solution and Attrition.

23. What does this look like?
1. RAINFALL – Water passing through the sandstone because it is impermeable but getting stuck at the clay level. Causes the rock to soften and become weak
3 MAIN CAUSES OF CLIFF COLAPSE
3. Weathering – water gets into the cracks and freezes, expanding and breaking rock. Chemical weathering also erodes the cliff
SAND
CLAY
2. Waves are hitting the bottom of the cliff causing weakness and the rocks to be eroded away the power of the sea
You will now need to draw this from the board

24. This is one from earlier
You need this information in your book

25. TO help you for the next activity
Firstly you will need to read the newspaper information on Mrs Wrightson and her tea room and the problems that the sea was causing.
To support this you will to watch a clip (click on pic) about the location and make some notes. You will need this for next lesson.
In your exercise books you need to highlight the key points and make notes

26. In pictures Coastal village living on the edge
The difference 15 years can make

27. Final task
With the information from the video, Newspaper and textbook page 16, you will now need to answer in full sentences questions 1 to 4 from your turn page 17.
Please hand books in at the end of the lesson.

28. Now we’ll combine what we’ve learned
Now we’ll combine what we’ve learned. What is happening at Happisburgh in Norfolk?
Read through as a class page 16 in the geog 2 book.
Use what you have found out from Pages 16 and 17 to write a newspaper article to:
DESCRIBE what happened.
EXPLAIN why it happened.
Include evidence, facts and quotations

29. Set your work out like this…

30. Hemsby and Norfolk storm surge Decemeber 2013 Newspaper Article
Level 4 DESCRIBE:
Who did the cliff collapse effect?
Where did it happen?
What happened?
Who did it effect?
When did it happen?
Level 5 EXPLAIN:
What factors cause cliffs to collapse?
Uses and explains freeze thaw and chemical weathering?
Uses and explains the types of wave erosion- Hydraulic action? Abrasion? Solution? Attrition?
How did rain effect the cliff?
How did weathering effect the cliff?
How did wave erosions effect the cliff?
Why did the clay in the cliff make a collapse more likely?
Level 6 Does it include a conclusion to link all these ideas to show that it was likely that one day the cliff would collapse

31. Plenary: What are the three factors that combine to make cliffs collapse?
Weathering
Rain
Wave Erosion
Mini white board task

32. What attacks the top of cliff?
Weathering
Mini white board task

33. What type of weather occurs when acidic rain water dissolves the rocks?
Chemical Weathering
Mini white board task

34. When water freezes in cracks it expands making the cracks bigger and breaking up the rock. This is?
Freeze Thaw Weathering
Mini white board task

35. Rain makes clay cliffs?
Slippery
Mini white board task

36. Wave erosion attacks which part of the cliff?
The Base or bottom of the cliff
Mini white board task

37. Waves fling pebbles at the cliff wearing it away like sandpaper
Waves fling pebbles at the cliff wearing it away like sandpaper. This is called?
Abrasion
Mini white board task

38. The waves hammer at the cliffs
The waves hammer at the cliffs. Water is forced into cracks compressing the air inside. This causes the rock to break. We call this?
Hydraulic Action
Mini white board task

39. Sea water dissolves soluble material in rock. This is called?
Solution
Mini white board task

40. What factors make a cliff collapse more likely?
Soft rock like clay.
Heavy rain.
Water logged clay.
Powerful waves.
Mini white board task

41. Holbeck Hall Hotel Newspaper Article
Does your article include the following ideas? Succeed by making sure that all these ideas are discussed using the POINT Evidence Explain Explore language approach.
Level 4 DESCRIBE:
What was the Holbeck Hall?
Where did it happen?
What happened?
Who did it effect?
When did it happen?
Level 5 EXPLAIN:
What factors cause cliffs to collapse?
Uses and explains freeze thaw and chemical weathering?
Uses and explains the types of wave erosion- Hydraulic action? Abrasion? Solution? Attrition?
How did rain effect the cliff?
How did weathering effect the cliff?
How did wave erosions effect the cliff?
Why did the clay in the cliff make a collapse more likely?
Level 6 Include a conclusion to link all these ideas to show that it was likely that one day the cliff would collapse.

42. Holbeck Hall Hotel Newspaper Article
Does your article include the following ideas? Succeed by making sure that all these ideas are discussed using the POINT Evidence Explain Explore language approach.
Level 4 DESCRIBE:
What was the Holbeck Hall?
Where did it happen?
What happened?
Who did it effect?
When did it happen?
Level 5 EXPLAIN:
What factors cause cliffs to collapse?
Uses and explains freeze thaw and chemical weathering?
Uses and explains the types of wave erosion- Hydraulic action? Abrasion? Solution? Attrition?
How did rain effect the cliff?
How did weathering effect the cliff?
How did wave erosions effect the cliff?
Why did the clay in the cliff make a collapse more likely?
Level 6 Include a conclusion to link all these ideas to show that it was likely that one day the cliff would collapse.

43. Holbeck Hall Hotel Newspaper Article
Poziom 4 DESCRIBE: Co było Hall Holbeck? Gdzie to się stało? Co się stało? Kto to zrobił efekt? Kiedy to się stało? Poziom 5 EXPLAIN: Jakie czynniki powodują skały do upadku? Wykorzystuje i wyjaśnia odwilży zamrażać i chemiczne wietrzenie? Wykorzystuje i wyjaśnia rodzaje fal działania erozji-hydrauliczne? Ścieranie? Rozwiązanie? Ścieranie? Jak deszcz efekt skały? Jak atmosferycznych efekt skały? Jak nadżerki fali efekt skały? Dlaczego gliny w klifie się załamania bardziej prawdopodobne? Poziom 6 Dołącz wniosku, w celu połączenia wszystkich tych pomysłów, aby pokazać, że jest prawdopodobne, że pewnego dnia klifu upadnie
Undo edits

44. Weathering
Weathering attacks the _____ of the cliff
C______________ weathering: ______ soaks in and ____________ minerals
Freeze- thaw: In winter water __________ in the cracks making them _________.
Cliff Collapse
Wave Erosion
Waves attack the _______ of the
cliff through H____________
Action, A___________,
S____________ and Attrition.
Rain
Rain ________ into the cracks. It makes
______ cliffs very s_______.
The clay can just slide away.
Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution