Lesson 3 Headlands, Cracks, Caves, Arches and Stacks

Today’s ObjectivesToday’s Objectives

To recap wave erosion processesTo recap wave erosion processes Investigate the landforms that waves Investigate the landforms that waves

create by erosioncreate by erosion To describe how these come To describe how these come

together to form caves, arches, together to form caves, arches, stacks and stumpsstacks and stumps

Let’s get started…Let’s get started…

Record the 7 answers on Mini White

boards!

Waves do three things.Waves do three things.Write down the missing keywords .Write down the missing keywords .

1.1. Waves _____ the coast.Waves _____ the coast.

2.2. Waves ______ the eroded material.Waves ______ the eroded material.

3.3. Waves ______ this material in Waves ______ this material in sheltered areas where they lose sheltered areas where they lose their energy.their energy.

4. Write down the keyword 4. Write down the keyword described below:described below:

Waves force water into cracks under Waves force water into cracks under pressure. This helps break up the pressure. This helps break up the rock.rock.

5. Write down the keyword 5. Write down the keyword described below:described below:

Water dissolves soluble material Water dissolves soluble material from the rock.from the rock.

6. Write down the keyword 6. Write down the keyword described below:described below:

Waves fling sand,pebbles and large Waves fling sand,pebbles and large stones against the rock. This acts as stones against the rock. This acts as sand paper wearing away the rock.sand paper wearing away the rock.

7. Write down the keyword 7. Write down the keyword described below:described below:

Waves knock together the pieces of Waves knock together the pieces of rock broken off by erosion. These rock broken off by erosion. These wear down into smaller and smaller wear down into smaller and smaller pieces.pieces.

The rock wears down into The rock wears down into shingle shingle (Pebbles) (Pebbles) and and sand.sand.

AnswersAnswers

1.1. Waves Waves erodeerode (wear down) the (wear down) the coast.coast.

2.2. Waves Waves transporttransport (move) the (move) the eroded material.eroded material.

3.3. Waves Waves depositdeposit (drop) this material (drop) this material in sheltered areas where they lose in sheltered areas where they lose their energy.their energy.

4. 4. Hydraulic ActionHydraulic Action Waves force water into cracks Waves force water into cracks under pressure. This helps break up the rock.under pressure. This helps break up the rock.

5. 5. SolutionSolution Water dissolves soluble material from the rock.Water dissolves soluble material from the rock.

6. 6. ABRAABRAsionsion Waves fling sand,pebbles and large stones Waves fling sand,pebbles and large stones against the rock. This acts as sand paper wearing away the rockagainst the rock. This acts as sand paper wearing away the rock

7. 7. ATTATTrition rition Waves knock together the pieces of rock Waves knock together the pieces of rock broken off by erosion. And smaller pieces. These wear down broken off by erosion. And smaller pieces. These wear down into smaller.The rock wears down into into smaller.The rock wears down into shingle (Pebbles) shingle (Pebbles) and and sand.sand.

Erosion of a headland

Caves, Arches, Stacks and stumps

The Big Picture

When complete:

Swap with another table and let’s see how you’ve done.

There are 12 marks available!

Crack

Cave

Arch

Stack

Stump

Erosion of a Headland Underlined title 1

2

4

5

3

6

9

87

10

11

12 Neat and clearly legible!

Watch these two clips…

http://www.bbc.co.uk/learningzone/clips/coastlines-caves-arches-and-stacks/8432.html

http://www.bbc.co.uk/learningzone/clips/wave-cut-platforms-and-headland-erosion/4021.html 4 Mins

2 Mins

What features do the erosion and weathering processes

produce?

1

2

3

4

This is a cave (‘Stair Hole’).

This is an arch (‘Durdle Door’).

This is a stack (Old Harry’s Rocks). These are stumps.

Caves, arches, stacks and stumps

Look at the diagram at the Look at the diagram at the bottom of Page 10.bottom of Page 10.

It tells us how a headland erodes to It tells us how a headland erodes to from from caves, arches, stacks and caves, arches, stacks and stumps.stumps.

We’ll read the labels together.We’ll read the labels together.

Make sure you choose the correct diagram!

Title: Title: Caves, Arches, Stacks Caves, Arches, Stacks and Stumpsand Stumps

Now copy the diagram at the bottom Now copy the diagram at the bottom of page 10 in geog 2.of page 10 in geog 2.

Include the labels.Include the labels.

Draw large clear diagrams. Add Draw large clear diagrams. Add colour.colour.

Make sure you choose the correct diagram!

Extension:Extension: Caves, arches, stacks and stumps are not the Caves, arches, stacks and stumps are not the

only landforms created by wave erosion…only landforms created by wave erosion…

Read the diagram on Page 8 about a wave cut Read the diagram on Page 8 about a wave cut platform.platform.

Now create a fully labelled series of diagrams Now create a fully labelled series of diagrams to explain how these are created. Title: to explain how these are created. Title: Wave Wave Cut platformsCut platforms

Erosion of a headland : Caves, Arches, Stacks and Stumps A headland is an area of hard rock which sticks out into the sea. When headlands erode they

create distinct features such as caves, arches, stacks and stumps. The diagram below shows the 5 stages in the erosion of a headland

Use the keywords at the bottom to complete the description of each picture!

Stage 1

_____________ attack a weakness in the

headland. E___________ is the w_______

away of the rock.

Stage 2

A C__________ is formed.

Stage 3

Eventually the cave E_________ through the

headland to form an _______.

Stage 4

The R_______ of the arch collapses leaving a column of rock called a _______ .

Stage 5

The stack collapses leaving a _________

EROSI ON STUMP WEARI NG WAVES ROOF

STACK ARCH CAVE ERODES