Exercise 1:
Go to this simulation and click on the play button to view the animation. Play it forward and backward and observe the relationships between the melting of the block of ice and the water level in the tank. Then go to this simulation and make similar observations. 

The water tanks simulate the world oceans. In the first example, the ice is floating in water. This would be an example of icebergs or Arctic ice floating on the ocean. In the second example the ice lies on a wood structure. The structure simulates a continent. The block of ice on top of the structure simulates ice grounded on top of a continent. This would be an example of ice sheets in Greenland and Antarctica.