The creation of U-shaped valleys and V-shaped valleys

• Aardrijkskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

Shaping landscapes: 

U-shaped valleys and V-shaped valleys

Learning objectives

After this lesson you can:

  

• describe in your own words how glaciers shape a landscape;
  
• name 5 glacial erosional landforms;
  
• name the erosive process that creates U-shaped valleys;
  
• name 1 depositional landform created by glaciers;
  
• name the erosive process that creates V-shaped valleys;
  
• name 1 distinctive feature of both a U-shaped valley and a V-shaped valley;
  
• recognise on a picture or in real life when travelling abroad if a valley was created by a glacier or by a river.

Flashback:
What two kinds of forces shape the landscape on Earth?

Flashback: endogenous or exogenous forces at work?

Flashback: endogenous or exogenous forces at work?

Flashback: endogenous or exogenous forces at work?

Glacial erosional landforms

How glaciers shape the landscape

• Plucking: rocks pulled off and carried away by the ice.

• Abrasion: grinding like sandpaper.

Depositional landforms created by glaciers

• Deposition: putting down rocks and sediment.

• Moraines.

• Also visible after glacier has melted away.

Leftover from a retreating glacier: U-shaped valley

• Hanging valleys

• Steep valley walls

Example of a U-shaped valley: 

Yosemite Valley, Yosemite National Park, USA

Flashback: endogenous or exogenous forces at work?

How rivers shape the landscape

• Water erodes river bed and river banks.

• Rivers flow faster in the upper river course, close to their source.

• High bedload transport in upper river course.

• V-shaped valleys can be found in the upper river course.

How rivers deposit sediment

Boulders

Pebbles

Coarse sand

(Fine) sand

Silt

Flashback:
Rivers can erode rock. How do we call this type of erosion?

This video is no longer available

explain

How fluvial erosion leads to a V-shaped valley

Formed by a river: V-shaped valley

• Valley walls are usually less steep compared to U-shaped valleys.

• Harder rock → steeper valley walls.

Example of a V-shaped valley: 

Grand Canyon of the Yellowstone, USA

What is the starting point of a glacier?

1. arête
2. hanging valley
3. cirque
4. pyramidal peak

How do we call the scraping of rocks along the bottom and sides of a glacier?

1. abrasion
2. plucking
3. ice flow
4. deposition

True or false:
Tributary glaciers erode smaller valleys than trunk glaciers.

1. true
2. false

Tributary glacier

Cirque

Arête

Terminal moraine

Trunk glacier

True or false:
Rivers deposit more sediment in the upper course than in the lower course.

1. true
2. false

Which statement about V-shaped valleys is correct?

1. If the rocks are soft and easy to erode by a river, then the walls of the valley become very steep.
2. Hanging valleys are distinctive features of V-shaped valleys.
3. V-shaped valleys are primarily formed in the middle course of rivers.
4. A V-shaped valley is formed when the sides of the valley break off due to mechanical weathering and mass movement.

What kind of valley do you see here?

1. U-shaped valley
2. V-shaped valley

What did you learn from this lesson that you did not know before?