The major oic divisions are defined in part by the tis, various archipelagos, and other criteria. The divisions are (in desding order of size):
Pacific O, which parates Asia and Australia from the Americas
Atlantic O, which parates the Americas from Eurasia and Africa
Indian O, which washes upon southern Asia and parates Afrid Australia
Southern O, sometimes sidered aension of the Pacific, Atlantid Indian Os, whicircles Antarctica.
Arctic O, sometimes sidered a a of the Atlantic, which covers much of the Arctid washes upon northern North Amerid Eurasia.
The Pacifid Atlantic may be further subdivided by the equator into northern and southern portions. Smaller regions of the os are called as, gulfs, bays, straits and other names.
Geologically, an o is an area of oic crust covered by water. Oic crust is the thin layer of solidified volic basalt that covers the Earth’s mantle. tial crust is thicker but less den. From this perspective, the earth has three os: the World O, the Caspian Sea, and Black Sea. The latter two were formed by the collision of Cimmeria with Laurasia. The Mediterranean Sea is at times a discrete o, becau teic plate movement has repeatedly broken its e to the World O through the Strait of Gibraltar. The Black Sea is ected to the Mediterrahrough the Bosporus, but the Bosporus is a natural al cut through tial roe 7,000 years ago, rather than a piece of oic a floor like the Strait of Gibraltar.
The major oic divisions are defined in part by the tis, various archipelagos, and other criteria. The divisions are (in desding order of size):
Pacific O, which parates Asia and Australia from the Americas
Atlantic O, which parates the Americas from Eurasia and Africa
Indian O, which washes upon southern Asia and parates Afrid Australia