The worksheet for this lesson can be downloaded here
As long as you have a freezer to hand, this lesson is straight forward to run and gives a great visual representation of how a glacier can change a V-shaped valley into a U-shaped valley. It also allows you to get out of the classroom, use technology and bring geography to life in a relatively simple way. You will need the help of your kitchen staff at school, a rectangular terrine pot with a layer of small pebbles and sand at the bottom, a large cooking tray and some grit.
Fill the pot with water and leave it to freeze overnight, or at this time of year maybe just outside. By the morning the perfect glacier will have formed, with the sand and pebbles frozen into the base (perfect for showing abrasion). Next, in the cooking tray use the grit to create your perfect V-shaped valley (My sculpting skills were not good enough to produce interlocking spurs, but give it a try!).
After removing the glacier from the terrine pot (pouring a little hot water on the bottom of the pot helps with this) I gave my pupils the opportunity to run their hands across the bottom of the glacier. This helped them understand how rough the base of a glacier is and how it can do so much 'damage' to a landscape.
Place your glacier at the top of your V-shaped valley and move it slowly down the valley to show evidence of the abrasion process occurring. The bulldozing effect carves out a U-Shaped valley and a terminal moraine builds up at the bottom. If you leave the glacier in the model for a few minutes before removing it, it will leave erratics dotted throughout the newly formed U-Shaped valley.
During the whole activity, my pupils were taking photos using their mobile phones, which they then used for a homework task. The pupils were asked to annotate images to show the different steps it takes to go from a V-Shaped valley to a U-Shaped valley, making sure they followed the sequence of events.
Exam practice from this lesson can include:
Explain the formation of a U-shaped valley. (4 marks)
Describe how a glacier transports material (3 marks)
Explain how a glacier erodes a landscape (3 marks)