004 - Advance and Retreat

Geographic Knowledge and Understanding

The changing distribution of extreme environments over time, including the advance and retreat of glaciers and natural desertification.

Key Concepts

Scale is vital when studying the changing distribution of extreme environments over time. Climate change at a global scale is having an impact on the local scale such as natural desertification and glacial retreat (and advance). Natural processes are involved in both scenarios. There are possibilities that actions of humans can accelerate the processes.

Aims

To be able to describe and explain the changing distribution of extreme environments over time.

To be able to describe the global situation regarding the changes to glaciers over time.

To be able to explain the processes linked to the advance and retreat of glaciers.

To be able to explain the processes associated with natural desertification.

Key Terminology

  • Snout
  • Accumulation
  • Ablation
  • Equilibrium
  • Systems Diagram

Define the words above by using the useful links below:

Useful Links

Image One - Glacier Systems Diagram

Taken From: https://www.slideshare.net/tudorgeog/l2-glacial-budget

Activity One - Describe

  • Watch the short clip below and describe the long term global trend in warming temperatures.

Activity Two - Glacial Changes

  1. How does a glacier actually form? Use the links in the 'Useful Resources' box to help you.
  2. Watch the youtube clip above and write notes on how glaciers move and how they help to shape the landscape.
  3. You defined what a system is for physical geography at the beginning of the lesson, now draw a systems diagram for a glacier.
  4. Using image two below describe the changes to the thickness of mountain glacial ice since the 1970s. Don't forget to include figures.

Image Two - Changes to Mountain Glacial Thickness Since 1970

Taken From: https://upload.wikimedia.org/wikipedia/commons/9/93/Glacier_Mass_Balance_Map.png

Taken From: https://upload.wikimedia.org/wikipedia/commons/9/93/Glacier_Mass_Balance_Map.png

Useful Resources

Geology - Glaciers

Image Two - Glacial Ice Formation

Activity Three - Desert Changes

  1. By watching the youtube clip above and reading the two articles in the 'Useful Resources' box, describe the natural and human causes of desertification.
  2. Using image three describe which areas of the world are vulnerable to desertification.

Image Three - A map to show the areas which are vulnerable to desertification

Taken From: https://upload.wikimedia.org/wikipedia/commons/thumb/6/68/Desertification_map.png/800px-Desertification_map.png

Taken From: https://upload.wikimedia.org/wikipedia/commons/thumb/6/68/Desertification_map.png/800px-Desertification_map.png

Useful Resources

The Guardian - Desertification: an ecological reality or a dangerous myth?

'Our Planet's Extreme Environments' text book by Codrington Pages 38 and 39

Taken From: https://syllabus2go.com/collections/solid-star-press/products/our-planets-extreme-environments-1st-ed-by-stephen-codrington

Exam Style Questions

State and explain one significant process involved in natural desertification. [1 + 3]

State and explain one significant process involved in glacial retreat. [1 + 3]