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. Click on the map to enlarge.
The blocks break off both from the east coast and the west coast. The ocean currents then control where these block go, some of them the size of apartment buildings.
The blocks from Greenland tend to search south, affecting Canada and Iceland.
Sea ice makes sailing dangerous, and the block can drift far south. Smaller ships are often in danger because of the ice. Large ships can often be affected as well; the Titanic is the famous example.
There is also ice that drifts from the Russian Arctic and from Svalbard. That ice often melts before reaching Icelandic shores.
Blocks of ice melt in time but they have on a few occasions 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 consequently.