How Big Are Icebergs?
Icebergs occur in the Atlantic, Arctic and Southern oceans. They are blocks of freshwater ice that break off from glaciers and float out to sea.
Only 10% of an iceberg is above the waterline. Icebergs float because the density of ice, 920 kg/m3, is lower than that of seawater at 1025 kg/m3.
In the North Atlantic, most icebergs originate from the glaciers of Western Greenland, where 15,000 to 40,000 icebergs are produced annually.
The tallest known iceberg in the North Atlantic was 168 metres (550 feet) above sea level, spotted in Melville Bay, Greenland in March 1957. It was as high as a 55 storey building.