Blocks of sea ice break annually from large ice caps in the Arctic. These blocks of ice can be up to kilometers in width.
The ice blocks cause problems where they go.
As the map shows, the largest blocks break off Greenland.
This causes problems for shipping, especially for smaller ships.
Blocks of ice melt in time but they have on a few occastions brought polar bears to Iceland, for example. They come from Svalbard and Greenland for the most part.
In 2008 two polar bears drifted to Iceland, one in 2010 and one in 2011. They were all shot consequenly.
Click on the picture to enlarge.