Icebergs

Icebergs are big lumps of floating ice that calve, or brake off, from the end of glaciers or polar ice caps. This often occurs when tides and waves move the ice up and down.

Calving of icebergs occurs mostly during the summer when the warm conditions partially melt the ice. Around 15,000 icebergs a year calve in the Artic.

Arctic icebergs vary from car-sized ones called growlers to mansion-sized blocks. The biggest iceberg, 11 km long, was spotted off Baffin Island in 1882.

The Petterman and Jungersen glaciers in northern Greenland form big table-shaped icebergs called ice islands. They are like the icebergs found in Antarctica.

Antarctic icebergs are much, much bigger than Arctic ones. The biggest iceberg, which was 300 km long, was spotted in 1956 by the icebreaker USS Glacier. Antarctic icebergs last for ten years on average; Arctic icebergs last for about two years.

Each year 375 or so icebergs drift from Greenland into the shipping lanes off Newfoundland. They are a major hazard to shipping in that area. The International Ice Patrol was set up in 1914 to monitor the icebergs after the great liner Titanic sank.