Observations and results
After the ice cubes melted, did the water level in the North Pole model remain unchanged, whereas the water level in the South Pole model increase?
The ice on the North Pole is in the form of a floating polar ice cap, whereas the ice on the South Pole is mainly in the form of an ice sheet on top of the continent of Antarctica. As floating ice melts into the water, the ice's solid volume is displaced as it becomes liquid by the same amount, so the water level in the North Pole model should not increase much as the ice cubes melt. However, when an ice sheet on a landmass (such as in Antarctica or Greenland) melts and flows into the “ocean,” this does cause an increase in the water level. This is what you should have observed in the South Pole model, with an increase of around one centimeter (0.4 inch), depending on the shape of the clay landmass and ice cubes. It's estimated that if all of the ice on the poles melted, sea levels would increase by at least 60 meters (200 feet), due to the ice covering the South Pole (as well as that on and around Greenland) melting, although the ice on Antarctica is not considered to be in danger of melting as soon as the Arctic ice cap.
Many people around the world enjoy living by the ocean, but even a small rise in sea levels will cause flooding of areas that are at a low elevation and close to the water. In 2007 a study reported that around 634 million people (about one in 10 people in the world) live in locations that are less than nine meters (30 feet) above sea level and are consequently at more immediate risk from rising seas.
Let the wet Play-Doh or modeling clay dry off a little bit before resealing it in its storage container.
More to explore
Study: 634 Million People at Risk from Rising Seas, from Nell Greenfieldboyce at National Public Radio
Climate and Global Change, from Windows to the Universe
Regarding global warming…, from the University of California, Santa Barbara, ScienceLine
Polar Puzzle: Will Ice Melting at the North or South Poles Cause Sea Levels to Rise?, from Science Buddies