As long as you have a freezer, this lesson is simple to prepare and gives students a great visual representation of how a glacier can change a V-shaped valley into a U-shaped one. It also allows you to get out of the classroom, use technology and bring geography to life in a relatively easy way.
The night before the lesson, I went to the school kitchen with a terrine lined with a layer of small pebbles. I filled the pot with water and left it to freeze overnight. By morning I had the perfect glacier, complete with sediment and crevasses on top.
In a large cooking tray and using some grit provided by the school's estates department (sand also works), I crafted a simple V-shaped valley.
When the glacier was "released" from the terrine I gave the pupils the opportunity to run their hands across the bottom of it. This helped them to realise how rough the base of a glacier really is and how much damage it can do to the landscape.
Next, I slowly moved the glacier down the grit valley from top to bottom. This shows how the abrasion process occurs. The bulldozing motion carves out a U-shaped valley and a terminal moraine build-up is left at the bottom.
Leaving the glacier in the model for a few moments before removing it will leave erratics (pieces of rock that differ from the size and type of rocks native to the area) dotted throughout the newly formed U-shaped valley.
My pupils took photos on their mobile phones throughout the process for a homework task in which they annotated the steps it takes to get from a V-shaped to a U-shaped valley.
Making models is always the best way to show how physical geography processes take place. I know my students find it the most interesting and memorable way to learn.