- Start by making your glacier. Glaciers aren’t just made of snow and ice, they also collect sand, soil, and rocks. Put water in the plastic cup (can add blue food coloring here) and then drop in some rocks/soil/sand. You can put it all in at once and freeze immediately, or make separate layers by only filling the cup halfway with water/rocks, freezing for a few hours, then repeating.
Freeze the glacier for several hours or overnight to make sure it is entirely frozen.
- Take the glacier out of the cup. What do you notice?
How have the rocks/sand affected the shape or texture of the glacier?
Make a “landscape” on the baking sheet. Pour a thin layer of oil and sprinkle flour on top. It will be easier to see the effect of the glacier if you have a solid layer of flour instead of just a little bit.
Make a prediction - what do you think will happen when you put the glacier in the landscape? Will it move? How will it interact with the oil/flour?
- Place the glacier somewhere on the sheet and observe what happens.
Try tilting the baking sheet to mimic a hill or mountain. Try making an uneven layer of flour - thinner in some areas and a thicker mound in others. What happens? How is the glacier melting? After some time has passed, do you notice any deposits from the glacier - places where the sand or rocks have melted out? What happened there?
What’s happening in this experiment?
Just like glaciers have sand and rocks in real life, glaciers move in real life, too! As new layers of snowfall on the glacier and increase the pressure on the lower layers, the glacier moves or “flows.” Tilting the baking sheet in this experiment mimics how real glaciers move, but real glaciers move under gravity and the force of their own weight. Glaciers are so huge and heavy that they push the land as they move, just like the glacier in this experiment pushed around the flour. You might have seen your glacier make a hill out of the flour is pushed out of the way. When real glaciers make hills like this, scientists call them terminal moraines. Glaciers can also make ridges to the side of where they traveled, which are called lateral moraines. Did you notice a stripe-like pattern in the flour underneath your glacier? These are called striations, and happen when glaciers scrape the Earth’s rock beneath them. The deposits of rock and sand that melt out of glaciers when they move and get left behind are called erratics. See if you can find terminal moraines, lateral moraines, striations, and erratics in your glacier model! If you can’t find them, how can you influence the glacier, land, or movement of the landscape to make them?