- Guttering (2 metre long)
- Bubble wrap £1
- 500 Marbles £10
- 10 pots
- 10 dice £5
- Instruction sheet (Download PDF)
The first job is to cut the U-shaped guttering into 10 x 20cm lengths and sand the edges. Line the gutter with bubble wrap (rough side up). Give each student 50 marbles in a pot. Place one end of the gutter on an atlas to provide a slope.
The winner of the game is the group that achieves the most net accumulation throughout the 30 year game.The gutter represents the U-shaped valley and the marbles represent ice. Ice accumulation = add more marbles; ice ablation = lose marbles.
Running the game
Students start with 15 marbles at the top end of the gutter. Use the bubble wrap rough side up to stop the marbles rolling everywhere. Teacher instructs when students can throw the dice. A low dice throw = net ablation; a high dice throw = net accumulation (see instruction card). Each throw represents one year. Allow 30 throws for 30 years. Each turn when they gain or lose ‘ice marbles’ they must say “Net accumulation!” or “net ablation!”
As the game proceeds the students’ marble glaciers will advance and thicken or retreat and thin.
At the end of the lesson students write up a short account of what happened to the glacier linking the gain or loss of ice marbles to glacier mass balance/ice budget.
|Start with 15 ice marbles|
|The snout advances!|