002 - Periglacial

Landforms

Geographic Knowledge and Understanding

Periglacial processes of freeze-thaw, solifluction and frost heave, and periglacial landscape features, including permafrost, thermokarst, patterned ground and pingos.

Key Concepts

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

Aims

  • To be able to describe the periglacial processes of erosion, transport and deposition.
  • To be able to explain how glacial processes contribute to the creation of landform features including permafrost, thermokarst, patterned ground and pingos.

Key Terminology

Like the previous lesson this one is also terminology heavy. While there is a list below of terms we will be using we will define them throughout the course of the lesson.

            • Periglaciation
            • Freeze-thaw
            • Solifluction
            • Frost heave
            • Permafrost
            • Thermokarst
            • Patterned ground
            • Pingos

If for whatever reason you need to quickly reference the meaning of these terms have a look in the useful links below:


Useful Links

Activity One - Watch

Watch the clip below and just be amazed at how the landscape changes when it is impacted by ice and water.

Activity Two - Describe

Before we even start to look at landforms created in periglacial areas we need to look at what a periglacial area is and what its characteristics are. Answer the following questions using the images above and the useful resources below:


      1. What are periglacial areas?
      2. Where can periglacial areas be found?
      3. Describe the climate of periglacial areas.
      4. What is permafrost?
      5. Describe the three different types of permafrost.
          • Continuous
          • Discontinuous
          • Sporadic
      6. Why is permafrost found at higher altitude closer to the equator?
      7. What is talik?
      8. What is the active layer?
      9. Why is the active layer important for landforms created in periglacial areas?

Useful Resources

Google Definition: Permafrost

'Glaciation and Periglaciation' text book by Knight pages 64-69

Activity Three - Processes and Movement

There are a number of key processes that occur in periglacial areas and these help to either break up the rock, transport it or deposit the rock.


Process

      1. Describe the process of freeze-thaw.
      2. Describe how chemical weathering occurs?


Movement

      1. What is gelifluction and how does it occur?
      2. What is frost heave and how does it occur?
      3. What is frost creep and how does it occur?

Useful Resources

physicalgeography.net - periglacial processes and landforms

'Glaciation and Periglaciation' text book by Knight pages 70-74

Activity Four - Periglacial Landforms

Now you know how material is weathered and how it can move we can begin to look at the different landforms found in periglacial areas. As the syllabus point focuses on four so shall we. Copy and complete the table below using the images, the slide share and the suggested text book below.

Periglacial Landform Guide

Useful Resources

Landforms.eu - solifluction

'Our Planet's Extreme Environments' by Codrington pages 47-49

An Amusing Clip - Conditions in the Artic - Baffin Island, Canada

Taken From: http://www.baffinisland.ca/uploads/2/5/7/7/25770190/5343443_orig.jpg

Image Ten - Location Map of Baffin Island

Exam Style Question

Identify the landform in the diagram and explain how it is formed. [1+3]