For much of the 20th century, the world recognized the oceans. These divisions are based on the continents that border them:
The smallest and shallowest, centered around the North Pole. The Emergence of the Fifth Ocean how many oceans are there
The creates a distinct ecological and biological boundary around the continent of Antarctica. Because the water within this current is colder and less salty than the waters to the north, scientists argued it deserved its own classification. In 2021 , the National Geographic Society officially recognized the Southern Ocean, bringing the total to five . Differing Perspectives For much of the 20th century, the world
The largest and deepest, stretching from the Americas to Asia and Australia. For much of the 20th century
