An iceberg is a mass of floating ice that has broken off from the edge of a glaciers or ice shelves and slipped into the ocean (see also: calving). They tend to float for weeks in the open ocean until they melt away.
Approximately 1/8 of an iceberg’s volume is above the water surface.
Icebergs are classified by their shape and size. In general, there are:
- tabular (“table” shaped) icebergs
- non-tabular (“mountain” shaped) icebergs.
Large icebergs can pose a significant threat to ships.