- A polynya (/pəˈlɪnjə/) is an area of open water surrounded by sea ice. It is now used as a geographical term for an area of unfrozen seawater within otherwise contiguous pack ice or fast ice. It is a loanword from the Russian word polynya (полынья; IPA: ), which refers to a natural ice hole and was adopted in the 19th century by polar explorers to describe navigable portions of the sea.