If the iceberg is sitting on the bottom of the ocean and NOT floating, would the water level rise as the ice melts?

Asked by: Unknown

Your iceberg must be ANCHORED to the bottom to keep it from floating to the surface, since its density is less than that of the liquid water around it. Because water EXPANDS when it freezes, a melted iceberg takes up less space than a frozen one. That means the level of water it is immersed in will LOWER, theoretically, as it melts. In a body of water as large as the ocean, of course, the change would be impossible to measure.

Answered by: Paul Walorski, B.A., Part Time Physics/Astronomy Instructor

Ice is less dense than water (which is why it floats). That means that a 1 pound of ice is actually physically bigger (has more volume) than when it's 1 pound of melted ice. Water expands when it freezes. It actually gets bigger. So the iceberg takes up more space frozen than it did when it wasn't frozen. Therefore... assuming the whole iceberg is underwater, the water level will actually go down a little as it melts.

Answered by: Frank DiBonaventuro, B.S., Air Force Officer, Physics grad, The Citadel