Download the printable Experiment Sheet here.
The great weight of glaciers causes the ice to grind away at nearby rocks to form a fine sediment called called rock flour, and large rocks from the valley and canyon walls as it moves. This experiment actually simulates what happens when a glacier melts and finally deposits the rock flour (chalk) and large boulders (gravel). When the glacier melts it drops boulders into a deposit called a moraine and glacial rock flour gives mountain lakes their milky color.
Here we use gelatin to demonstrate melting a glacier to see how rocks deposits are formed up when a glacier melts, from sugary fine rock flour to large boulders. We call these rocks that are deposited at the end of a melting glacier a "terminal moraine". Other moraines can form along the sides or even within or between glaciers.
Tray to collect water
- Prepare gelatin according to directions and suspend rocks in it (like fruit)
- After chilling, place gelatin on a tray to collect excess water
- Pour warm water on the gelatin
- Observe the result
Questions to consider:
- Describe what happens when the water hits the gelatin
- Have you ever noticed objects frozen in ice?
- Have you ever noticed rocks in nature that looked out of place?
Examples of Glaciers
Here in Greenland, a glacier is melting, leaving behind a sediment deposit at its end, or terminus. This is called a "terminal" moraine because it forms at the end of the glacier.