Activity Ideas

suggested by Dr. Gordon Hamilton

Activity I
Demonstrating Glacier Flow

Materials: One recipe of 'flubber'

Mix #1 Mix #2
3/4 cup of warm water 2 tsp of Borax
1 cup of white glue 1/2 cup of warm water
food coloring (optional)  

Stir the mixtures separately until both are well mixed. Pour mix #1 into mix #2 and a big glob of flubber will form. Kids love this bit. Work it for 2-3 minutes and drain any excess water. You can store it in ziplock bags for a few months; just rework the liquid back in each time.

Flubber behaves just like ice. At low stresses it deforms plastically. But at high stresses (like when you pull it apart) it undergoes brittle failure. Ice deforms plastically most of the time -- that's what allows it to flow. When brittle failure occurs, crevasses open up.
I like to let it flatten out from a round lump into a flat pancake. I also have a 4" PVC drain pipe that I cut in half lengthwise that I use to simulate a valley. You can incline the pipe and see how fast the flubber flows. Note that the flow is slower near the sides of the pipe because of friction from the valley walls. Or you can wet the pipe (the flubber should flow faster because of less friction). Or you can put one lump in the freezer for a while and compare how fast it flows compared to a warmer piece of flubber (warm ice deforms more easily than cold ice).
Or you can make a continent out of clay or papier maché including mountains, cover it with plastic wrap or foil and then try the 'flubber'.

Activity II
Sea Level Rise

Ice cubes
Fish tank or other large glass container

Sea level rise: a lot of people think that melting icebergs cause sea level rise. Not so! You can fill a fish tank with water and add some ice cubes. Note the water level on the tank. As the ice cubes melt, note the new water levels. They will be the same, because the ice cubes have already displaced an amount of water equal to their melted volume. Only grounded ice (ice on land) that melts will cause sea level rise. Try melthing and dripping the same amount of ice cubes over the side into the tank. The water level will go up.

Activity III
Ocean Circulation

Ice cubes, some fresh water, some made with salt
Fish tank or other large glass container
Food coloring

Ocean circulation: ocean circulation (which in turn drives atmospheric circulation and the re-distribution of heat on planet earth) is driven by melting of Antarctic ice. The process is called the "oceanic conveyor". Cold fresh water from melting polar ice sinks to the bottom of the ocean and forms an enormous submarine current that travels through all the world oceans. Without cold Antarctic water, this current would be shut off and there would be enormous changes in climate. You can see it in action by dropping ice cubes into the fish tank. Use different food colorings for different types of ice: freshwater ice and ice made with salty water. The food coloring currents that form on the bottom of the freshwater ice cubes will be much more vigorous.