001 - Glacial processes and landforms

Geographic Knowledge and Understanding

Glacial processes of erosion, transport and deposition, and landscape features in glaciated areas, including cirques/corries, lakes, pyramidal peaks/horns, arêtes, glacial troughs; lateral, medial and terminal moraine and erratics.




Key Concepts

The processes of erosion, transport and deposition are necessary for the creation of glacial landscapes.



Aims

To be able to describe the glacial processes of erosion, transport and deposition.
To be able to explain how glacial processes contribute to the creation of  landscape features  including cirques, glacial lakes, pyramidal peaks, arêtes, glacial troughs; lateral, medial and terminal moraine and erratics.




Key Terminology

  • Weathering
  • Erosion
  • Deposition
  • Snout
  • Supraglacial debris
  • Englacial debris
  • Subglacial debris
  • Frost Shattering
  • Abrasion
  • Plucking
  • Bergschrund
  • Rotational Movement
We will be using a lot of new terms throughout the course of this lesson, above are just a few to get started. Define the terms above using the useful link below.

Useful Link




Activity One - Glacial Movement

During the previous lesson we began to look at how glaciers are actually rivers of ice, we now need to look at how they actually move. The movement of the ice is essential for creating a number of the impressive landforms. Answer the following questions:


  1. Define the word internal deformation.
  2. Define the word basal sliding.
  3. Write a definition of subglacial deformation.
  4. What is a glacial surge?

 Useful Resources


Cliffsnotes - Glacial Movement (you may need to search for glacial movement)
National Snow and Ice Data Centre - Why do they move?
'Glaciation and Periglaciation' Advanced Topic Master by Jane Knight pages 18-27

Taken From: Amazon





Activity Two - Processes

Before we look at the specific erosional landforms you need to understand the processes behind the formation them. We will start with the basics and look at the differences between weathering and erosion. Watch the youtube clip below and write down the difference between weathering and erosion.

Glacial Erosion Defined


Now we can look at the specific forms of weathering and erosion that occur within a glacial environment. With the aid of diagrams explain how the following processes work (the first one is weathering and the others are forms of erosion):

                • Frost shattering (or freeze-thaw weathering)
                • Abrasion - What factors impact the rate of abrasion? What evidence is there on rocks to suggest that abrasion has taken place in an area?
                • Plucking
                • Rotational movement
  1. What is regolith?

 Useful Resources


'Glaciation and Periglaciation' text book by Knight Pages 28-31






Activity Three - Erosional Landforms

Now you are ready to actually look at the different landforms created in impressive glacial environments. Many of you have probably seen these landforms when you have skied or visited the mountains but perhaps not recognised them. Lets have a look at them now.

We will be using the app roundme.com to view different erosional landforms. 
  1. Download this app on to your phone.
  2. Open up the app and search for Richard Allaway - you are looking for the Aletsch Arena.
  3. If you are using your computer open up any other search engine than google and re-find this page.
We will investigate the different landforms created by glaciers as a group and then you will have time go back and look at them using the 360 Degree VR Googles.

Taken From: https://lh3.googleusercontent.com/H0UgglBFk6oOQH0LboUNhTW5zdDjeLhkCcB6s7zn7lY5OwAwzUiSC-S5R1YJzCF_0Gw=w300



  • Copy and complete the table below. Remember you need to be able to draw and annotate how landforms are created as it is a geographical skill they may ask you to do in the exam.

Erosional Glacial Landform Guide


 Useful Resources


'Glaciation and Periglaciation' text book by Knight pages 33-42
Taken From: https://images-na.ssl-images-amazon.com/images/I/51iEP8gWFJL._SX353_BO1,204,203,200_.jpg
Taken From: 
https://images-na.ssl-images-amazon.com/images/I/51iEP8gWFJL._SX353_BO1,204,203,200_.jpg

'Our Planet's Extreme Environments' text book by Codrington Pages 41-45
Taken From: https://cdn.shopify.com/s/files/1/1975/4441/products/bed31aa0-27fa-45d8-bda8-2490fa23e524.png?v=1501766254
Taken From: 
https://syllabus2go.com/collections/solid-star-press/products/our-planets-extreme-environments-1st-ed-by-stephen-codrington

Glacial Landforms








Activity Four - Depositional Landforms

You are now going to look at landforms that are created by glacial deposition. These are not always as easy to see as the erosional processes but they are there if you look closely.

      1. What is deposition?
      2. Remind yourselves what supra, en and subglacial transportation is.
      3. Why do glaciers deposit their material?
      4. How does material get into the middle of glaciers?
      5. Copy and complete the table below. Remember to annotate your diagrams.

Depositional Landform Guide


 Useful Resources


'Glaciation and Periglaciation' text book by Knight pages 43-54
Taken From: https://images-na.ssl-images-amazon.com/images/I/51iEP8gWFJL._SX353_BO1,204,203,200_.jpg
Taken From: https://images-na.ssl-images-amazon.com/images/I/51iEP8gWFJL._SX353_BO1,204,203,200_.jpg

'Our Planet's Extreme Environments' text book by Codrington Pages 45-46
Taken From: https://cdn.shopify.com/s/files/1/1975/4441/products/bed31aa0-27fa-45d8-bda8-2490fa23e524.png?v=1501766254





Exam style Question

Examine the relative importance of glacial (ice) erosion and deposition for the development of pyramidal peaks and terminal moraines. [10 marks]