Themes > Science > Earth Sciences > Hydrology, Meteorology, Climatology > Hydrology > Oceans > Experiments with the CyberScientist > How Much of an Iceberg Lurks under Water? Icebergs are floating masses of ice common in the Arctic and Antarctic regions. As a glacier moves toward the ocean, portions of it break off to form icebergs. Icebergs float because they are made of ice and snow, which are less dense than water. The surface of an iceberg consists mostly of snow, which is not very compact. So about how much of an iceberg is above water and how much is submerged? You can perform the following experiment to find out. You will need: plastic bag strong rubber band aquarium or large bowl water freezer ruler Here's what you do: Partly fill plastic bag with water. Close top off tightly with a rubber band. Place bag in freezer upright overnight. After water in bag is frozen solid, remove chunk of ice and measure its height. Float it in aquarium (without the fish) or bowl filled with water. Place the ruler into the water and measure the portion of ice that is above and below the water level. Do the math: Height Above Water / Total Height = Percent of Ice above Water Height Below Water / Total Height = Percent of Ice below Water What's your result? You should have arrived at approximately 1/8 (12.5 %) of the ice to be above water and 7/8 (87.5 %) of the ice to be below the surface. Icebergs float because they are made of ice and snow, which are less dense than water. The surface of the iceberg consists mostly of snow, which is not very compact. This portion of the iceberg remains above the waterline. The very compact ice core is relatively heavier and keeps a large percentage of the iceberg under water. When an iceberg tumbles over several times, its light snow layers are compacted. Thus, even more of the iceberg is submerged under water. Information provided by: http://www.onr.navy.mil