<P> An iceberg or ice mountain is a large piece of freshwater ice that has broken off a glacier or an ice shelf and is floating freely in open water . It may subsequently become frozen into pack ice (one form of sea ice). As it drifts into shallower waters, it may come into contact with the seabed, a process referred to as seabed gouging by ice . Also, about 91% of an iceberg is below the surface of the water . </P> <P> The word "iceberg" is a partial loan translation from Dutch ijsberg, literally meaning ice mountain, cognate to Danish isbjerg, German Eisberg, Low Saxon Iesbarg and Swedish isberg . </P>

What portion of an iceberg is below the water surface