Icebergs in the Southern Ocean
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Ute Kaden/PolarTREC


Icebergs are large pieces of ice that are floating in the ocean. They broke off of ice shelves or glaciers in Earth’s polar regions. Icebergs are a part of the cryosphere.

Almost all of an iceberg is below the surface of the seawater.  Because ice is less dense than water, a small portion of the iceberg stays above the seawater. Some icebergs are small.  Others are huge. The largest ones are known as ice islands.
In 1912, a brand new ship called the RMS Titanic, collided with an iceberg in the North Atlantic on its first voyage. The collision caused the boat to break apart and sink.  Only about a quarter of the passengers and crew who were on board the Titanic survived the shipwreck. Since then, people have been keeping track of the location of icebergs and warning sailors when the danger is high. In an average year, nearly 500 icebergs pass through the shipping routes in the North Atlantic Ocean. Today satellites are used to keep track of the icebergs locations. 

As they travel from the polar areas where they form into warmer waters, the ice melts, and icebergs become smaller.

Last modified April 18, 2007 by Lisa Gardiner.

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