What is weathering and erosion?

Learning Objectives;

1. To understand processes of weathering and erosion in

glaciated landscapes.

2. To understand how landforms of erosion are created.

What is weathering and erosion?

• Weathering – the break-down of rocks (by physical, chemical and biological action).

• Erosion – the wearing away of rocks by the wind, rivers, sea and ice.

• The difference between the two is that erosion involves movement

Freeze Thaw WeatheringOn your worksheet – complete the following

notes….

Freeze thaw weathering

• Debris from freeze thaw weathering

• People – for scale!

• Erosion is the break down and wearing away of rocks involving movement. Ice erodes by 2 main processes – plucking and abrasion.

Glacial Erosion

1) Plucking

• Plucking is when rocks and stones become frozen to the base of the glacier and are ‘plucked’ from the ground as the glacier moves down the valley.

2) Abrasion

• Abrasion occurs when rocks and stones, picked up by the glacier, through plucking at the bottom of the glacier, are rubbed along the bottom of the valley, digging it out.

Abrasion that has been carried out over rocks in Iceland – smoothing the

rocks

Mars Bar time!

• Get out your mars bar and listen to my instructions to understand why a mars bar is like a glacier!

Landforms of glacial Landforms of glacial erosionerosion

1. Corrie (or Cirque)

2. Arêtes

3. U-shaped valley

4. Pyramidal Peak

5. Hanging Valley

How does the landscape change after a glacial How does the landscape change after a glacial period?period?

Video of glaciated erosional features

The Main Event • You have a pack on your desks – in this pack

you have.1. Diagram of a glaciated area2. Five explanation cards of how the landforms of erosion were created

• In pairs can you identify the 6 key features from the information provided. Write the correct names next to the numbers.

• You only need to use numbers 1,2,3,4,9 & 10 (one feature appears twice

• Then annotate the diagram to explain how they formed

Corries What

happens when two

corries erode back

towards each other?

Corrie – contour patternCorrie – contour pattern

Corrie

contours close

together = ???

Arete

corrie

3) U shaped 3) U shaped valleyvalley

Your turn!

Homework

Complete the worksheet on a recent fieldtrip to a glaciated area

Gimme 5

• Think of one thing new that you have learnt today and I will ask 5 people to tell me what they have learnt in this lesson!