the density contrast between glacial ice and liquid water means that at least 1/9 of the floating ice is above the ocean surface, depending on how much pressurized air is contained in the bubbles within the glacial ice, stemming from compressed snow. the formula for the denominators above is formula_1, density of cold seawater divided by kg/m is about 1.028 and that of glacial ice from about 0.85 to well below 0.92, the limit for very cold ice without bubbles. the height of the shelf above the sea can be even larger, if there is a lot of less dense firn and snow above the glacier ice.