Lesson 6 Why do cliffs collapse?

Why do Cliffs Collapse?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.

Mini white board investigationMini 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.

What is happening to the cliff in this video?

What is happening to the cliff in this video?

• http://www.bbc.co.uk/learningzone/clips/coastal-landforms-blowholes-and-cliff-slumping/3085.html

• 2 mins

• What type of rocks make up the cliff that collapsed?

• Are they hard or soft?

• What factors caused it to collapse?

What factors make coastal erosion worse?

What factors make coastal erosion worse?

• http://www.bbc.co.uk/learningzone/clips/coastal-erosion-at-holderness-east-yorkshire/3187.html

• 1 min

• What could make a cliff more likely to collapse?

Sometimes it is a spectacular event!Sometimes it is a spectacular event!

What happened?What happened?

• Read page 16 of geog 2 together.

You will use this later to write a newspaper report of the disaster.

Objective 1

Objective 2

Understand that weathering, rain and wave erosion combine

to cause cliffs to collapse.

Objective 2

Understand that weathering, rain and wave erosion combine

to cause cliffs to collapse.

Weathering

Rain

Wave Erosion

In your Exercise books …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

Cliff Collapse

Weathering

Weathering attacks the _____ of the cliff

C______________ weathering: ______ soaks in and ____________ minerals

Freeze- thaw: In winter water __________ in the cracks making them _________.

Rain

Rain ________ into the cracks. It makes

______ cliffs very s_______.

The clay can just slide away.

Wave Erosion

Waves attack the _______ of the

cliff through H____________

Action, A___________,

S____________ and Attrition.

Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

WeatheringWeathering

• Attacks the top of the cliff in two ways• Chemical Weathering

• Freeze Thaw Weathering

Remember science…

Water trickles into cracks.In icy weather it freezes, forcing the cracks wider until the rock breaks up.

Remember Science?

Water reacts with Carbon dioxide in the air. The water becomes slightly acidic. (Carbonic acid). This dissolves the rock.

WeatheringWeathering• Attacks the top of cliff

• Chemical• Freeze Thaw

Now add an explanation to your web diagram of how weathering weakens the

cliff

Cliff Collapse

Weathering

Weathering attacks the _____ of the cliff

C______________ weathering: ______ soaks in and ____________ minerals

Freeze- thaw: In winter water __________ in the cracks making them _________.

Rain

Rain ________ into the cracks. It makes

______ cliffs very s_______.

The clay can just slide away.

Wave Erosion

Waves attack the _______ of the

cliff through H____________

Action, A___________,

S____________ and Attrition.

Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

Now complete this section of

your web diagram.

Objective 2Understand that weathering, rain and wave erosion combine to cause

cliffs to collapse.

Objective 2Understand that weathering, rain and wave erosion combine to cause

cliffs to collapse.

Weathering

Rain

Wave Erosion

RainRain

• 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

Cliff Collapse

Weathering

Weathering attacks the _____ of the cliff

C______________ weathering: ______ soaks in and ____________ minerals

Freeze- thaw: In winter water __________ in the cracks making them _________.

Rain

Rain ________ into the cracks. It makes

______ cliffs very s_______.

The clay can just slide away.

Wave Erosion

Waves attack the _______ of the

cliff through H____________

Action, A___________,

S____________ and Attrition.

Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

Now complete this section of

your web diagram.

Objective 2

Understand that weathering, rain and wave erosion combine to cause cliffs to collapse.

Objective 2

Understand that weathering, rain and wave erosion combine to cause cliffs to collapse.

Weathering

Rain

Wave Erosion

Wave ErosionWave 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

Cliff Collapse

Weathering

Weathering attacks the _____ of the cliff

C______________ weathering: ______ soaks in and ____________ minerals

Freeze- thaw: In winter water __________ in the cracks making them _________.

Rain

Rain ________ into the cracks. It makes

______ cliffs very s_______.

The clay can just slide away.

Wave Erosion

Waves attack the _______ of the

cliff through H____________

Action, A___________,

S____________ and Attrition.

Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution

Now complete this section of your web diagram.

Cliff Collapse

Weathering

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

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.

How did you get on?

What does this look like? What does this look like? 3 MAIN CAUSES OF CLIFF COLAPSE

• 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. Weathering – water gets into the cracks and freezes, expanding and breaking rock. Chemical weathering also erodes the cliff

• 2. Waves are hitting the bottom of the cliff causing weakness and the rocks to be eroded away the power of the sea

CLAY

SAND

You will now need to draw this from the boardYou will now need to draw this from the board

This is one from earlierThis is one from earlier

• You need this information in your book

TO help you for the next activityTO 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

In picturesIn pictures

• Coastal village living on the edge

• The difference 15 years can make

Final taskFinal 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.

Now we’ll combine what we’ve learned.What is happening at Happisburgh in

Norfolk?

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

HEADLI NE- Get the reader’s attention!

Picture

Report by: Your name

DESCRI PTI ON : What Happened?

DESCRI PTI ON continued.

EXPLAI N why it happened. Why do cliff s collapse?

Set your work out like this…

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

Hemsby and Norfolk storm surge Decemeber 2013 Newspaper Article

Plenary: What are the three factors that combine to make cliffs collapse?Plenary: What are the three factors

that combine to make cliffs collapse?

• Weathering

• Rain

• Wave Erosion

Mini white board task

What attacks the top of cliff?What attacks the top of cliff?

• Weathering

Mini white board task

What type of weather occurs when acidic rain water dissolves the

rocks?

What type of weather occurs when acidic rain water dissolves the

rocks?

• Chemical Weathering

Mini white board task

When water freezes in cracks it expands making the cracks bigger and breaking up the rock. This is?

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

Rain makes clay cliffs?Rain makes clay cliffs?

• Slippery

Mini white board task

Wave erosion attacks which part of the cliff?

Wave erosion attacks which part of the cliff?

• The Base or bottom of the cliff

Mini white board task

Waves fling pebbles at the cliff wearing it away like sandpaper. This

is called?

Waves fling pebbles at the cliff wearing it away like sandpaper. This

is called?

• Abrasion

Mini white board task

The waves hammer at the cliffs. Water is forced into cracks compressing the air inside. This causes the rock to break.

We call this?

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

Sea water dissolves soluble material in rock. This is called?

Sea water dissolves soluble material in rock. This is called?

• Solution

Mini white board task

What factors make a cliff collapse more likely?

What factors make a cliff collapse more likely?

• Soft rock like clay.

• Heavy rain.

• Water logged clay.

• Powerful waves.

Mini white board task

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.

Holbeck Hall Hotel Newspaper ArticleDoes 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.

Holbeck Hall Hotel Newspaper ArticleDoes your article include the following ideas? Succeed by making sure that all these ideas are discussed using the POINT Evidence Explain Explore language approach.

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 upadnieUndo edits

Holbeck Hall Hotel Newspaper Article

Cliff Collapse

Weathering

Weathering attacks the _____ of the cliff

C______________ weathering: ______ soaks in and ____________ minerals

Freeze- thaw: In winter water __________ in the cracks making them _________.

Rain

Rain ________ into the cracks. It makes

______ cliffs very s_______.

The clay can just slide away.

Wave Erosion

Waves attack the _______ of the

cliff through H____________

Action, A___________,

S____________ and Attrition.

Freezes Rain Chemical Larger Dissolves Slippery Freeze-thaw Soaks Hydraulic Clay Abrasion Top Solution