Over those 106 years the famed publication has listed four oceans on Earth — the Atlantic, Pacific, Indian and Arctic. Those maps are now being redrawn.
A fifth ocean has been designated by the magazine: the icy waters surrounding Antarctica below the Earth's southern 60th parallel is officially being named the Southern Ocean.
The move is significant beyond adding one more name for grade school students to remember. The Southern Ocean is fenced from the the northern oceans by a fast current that circles the Earth from west to east around Antarctica in a band centered around a latitude of 60 degrees south.
The waters south of that Antarctic Circumpolar Current are colder and ecologically distinct, the magazine says, making a home for thousands of species that can live nowhere else on Earth.
"The Southern Ocean encompasses unique and fragile marine ecosystems that are home to wonderful marine life such as whales, penguins, and seals,” said National Geographic Explorer in Residence Enric Sala said in the announcement.