What Is an Iceberg?
If a glacier reaches the sea, its forward edge breaks off, forming huge floating blocks of ice called icebergs. Icebergs are pieces of ice formed on land which float in an ocean. Icebergs come in all shapes and sizes, from ice-cube-sized chunks to ice islands the size of a small country.
The term “iceberg” refers to chunks of ice larger than 5 meters (16 feet) across. Smaller icebergs, known as bergy bits and growlers, are a great danger to ships when they drift into shipping lanes as they are harder to spot.
The largest icebergs weigh several million tons. These icebergs tower more than 200 feet above the water. This is only a small part of the whole iceberg. The part below water is about seven times as large as the part above. Icebergs often drift far out to sea before they melt and finally disappear.
The North Atlantic and the cold waters surrounding Antarctica are home to most of the icebergs on Earth. In the North Atlantic Ocean, the main sources of icebergs are the glaciers of Greenland.