001 - Glacial processes
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.
The processes of erosion, transport and deposition are necessary for the creation of glacial landscapes.
- 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.
- Supraglacial debris
- Englacial debris
- Subglacial debris
- Frost Shattering
- 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.
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:
- Define the word internal deformation.
- Define the word basal sliding.
- Write a definition of subglacial deformation.
- What is a glacial surge?
Cliffsnotes - Glacial Movement (you may need to search for glacial movement)
'Glaciation and Periglaciation' Advanced Topic Master by Jane Knight pages 18-27
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.
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?
- Rotational movement
- What is regolith?
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.
- Download this app on to your phone.
- Open up the app and search for Richard Allaway - you are looking for the Aletsch Arena.
- 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.
- 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.
Time for Geography - Great videos - cirques, aretes, pyramidal peak and U shaped valley
'Glaciation and Periglaciation' text book by Knight pages 33-42
'Our Planet's Extreme Environments' text book by Codrington Pages 41-45
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.
- What is deposition?
- Remind yourselves what supra, en and subglacial transportation is.
- Why do glaciers deposit their material?
- How does material get into the middle of glaciers?
- Copy and complete the table below. Remember to annotate your diagrams.
Exam style Question
Examine the relative importance of glacial (ice) erosion and deposition for the development of pyramidal peaks and terminal moraines. [10 marks]