Icebergs frequently occur off the coast of Antarctica and in the North Atlantic. More than ten thousands icebergs break away from the coast of Greenland each year and these can be the size of a dining table, or as high as a ten storey building.
Icebergs are huge floating lumps of frozen fresh water. In the Spring and Summer large bits of glaciers and ice sheets break off and fall into the sea . The technical term for this is 'calving'.
Some of the largest icebergs are over 200 feet tall and a mile in diameter and the part that is visible above the surface of the water is only one eight of the whole thing.
Icebergs are a hazard to shipping, especially around the coast of Newfoundland where their numbers can reach almost 400 each year. Many icebergs melt very quickly when they come into contact with sea water but the very large ones can travel up to 2000 miles before they melt completely.
The more global warming there is, the more icebergs will be released into the ocean. Scientists have discovered that these huge blocks of ice are not sterile, lifeless environments. They play host to many different forms of life and have the ability to soak up, or trap carbon dioxide.
Perhaps more significantly, these icebergs carry material from the land where they originated and alter the biological make-up of the sea. When they melt this biological matter forms a zone in the sea that can be enjoyed by krill, plankton and fish.
Melting Antarctic ice floes are causing sea levels to rise but the ability of the bergs to act as a kind of carbon dioxide sink has a positive effect on the environment. Maybe it's time for scientists to look again and factor in the positive effects when they make their predictions.
Much detailed work has been done of the make-up of icebergs and their effect on biological sea life and their movements have been tracked using satellite data but there is still a great deal of research to be done. Perhaps nature has found its own way of combating the increasing carbon dioxide contents of our atmosphere.
