North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be described as the northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Tectonic Plate, Greenland is included as part of North America geographically.