What Are Icebergs?
An iceberg is a mountain of ice floating in the sea. It was once part of a glacier. In many places glaciers flow right down to the sea. At the ocean’s edge, big chunks of glacier break off and fall into the sea.
Icebergs form when chunks of ice calve, or break off, from glaciers, ice shelves, or a larger iceberg. Icebergs travel with ocean currents, sometimes smashing up against the shore or getting caught in shallow waters.
Icebergs exist in all sizes—from small, flat “growlers” to mountains of ice many miles long, rising hundreds of feet above the ocean’s surface. The North Atlantic and the cold waters surrounding Antarctica are home to most of the icebergs on Earth.
What people see is just the tip of the iceberg. Most of it is hidden under water. Because of this, icebergs are dangerous to ships at sea. Icebergs often drift far out to sea before they melt and finally disappear.