Pack ice is sea ice that
formed somewhere else and floated to where it is now,
this may have been a few miles away or several hundred miles
away. In the summer months as in this picture, the ice may have
been recently broken up or has not encountered conditions cold
enough to freeze it all together again.
Such loose pack is relatively
easy to make a way through as the pieces of ice are generally
just pushed out of the way to the side rather than being broken
unless they are particularly large.
Picture courtesy of Mike Usher
- Mike went on a Ross Sea expedition on board the Kapitan Khlebnikov
You can purchase a selection of Mike's pictures