Icebergs

Icebergs are large pieces of land ice that have broken off from ice shelves or glaciers. This is caused by warm temperatures. The process of them breaking off of the larger ice mass is called calving.Between 10,000 to 15,000 icebergs are calved each year.

They float in the sea, as ice is less dense than water, and the wind and the current causes them to move.

Although all icebergs form the same way, those that originate in Artci and Antarctic regions differ. Ice bergs with steep, narro pinnacles, sometimes know as castle icebergs, only form in Arctic regions, while large, flat (tabula) icebergs are only calved in Antarctica. These differences are caused by the ice itself and the land underneath. Pinnacle icebergs are steep because they are calved from mountain glaciers, whil tabular icebergs form from much flatter ice sheets.

Only around one tenth of an iceberg is visible above water.

They generally range in size from 1 to 75 metres (3 to 250 feet) and they can weigh up to around 200,000 tonnes.