When an iceberg floats in sea water, what fraction of its volume is submerged?
sea water density is about 1.03 (tonnes per cubic meter or grams per cubic centimeter) ice has a density of about 0.92. 0.92/1.03 is about 0.89, or roughly 90 % of the volume of an iceberg will offset its equivalent mass of seawater. You could get a more precise value if you could actually guarantee a constant density for any given sample of ice and seawater, but reality is not so kind. Water density varies because of the presence of suspended solids, and variable proportions of fresh water (a potentially very important problem when dealing with icebergs, for obvious reasons) and iceberg density varies because of the presence of air bubbles, captured solids (crushed rock and stuff) and even whether the ice is from deep compaction or near the surface of the ice source, so not really possible to estimate better (more exactly) than a ratio of about 90%.
