Oceania is a geographic region that includes Australasia, Melanesia, Micronesia and Polynesia.Spanning the eastern and western hemispheres, Oceania has a land area of 8,525,989 square kilometres (3,291,903 sq mi) and a population of over 41 million.
Micronesia, which lies north of the equator and west of the International Date Line, includes the Mariana Islands in the northwest, the Caroline Islands in the centre, the Marshall Islands to the west and the islands of Kiribati in the southeast.
Melanesia, to the southwest, includes New Guinea, the world’s second largest island after Greenland and by far the largest of the Pacific islands. The other main Melanesian groups from north to south are the Bismarck Archipelago, the Solomon Islands archipelago, Santa Cruz, Vanuatu, Fiji and New Caledonia.
Polynesia, stretching from Hawaii in the north to New Zealand in the south, also encompasses Tuvalu, Tokelau, Samoa, Tonga and the Kermadec Islands to the west, the Cook Islands, Society Islands and Austral Islands in the centre, and the Marquesas Islands, Tuamotu, Mangareva Islands, and Easter Island to the east.
Australasia comprises Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. Most of Australasia lies on the southern portion of the Indo-Australian Plate, flanked by the Indian Ocean to the west and the Southern Ocean to the south. The bulk of Australasia sits on the Indo-Australian Plate, together with India.
When compared to continental regions, Oceania is the smallest in land area and the second smallest in population after Antarctica – which has a population of zero!
Oceania has a diverse mix of economies from the highly developed and globally competitive financial markets of Australia and New Zealand, which rank high in quality of life and human development index, to the much less developed economies that belong to countries such as Kiribati and Tuvalu, while also including medium-sized economies of Pacific islands such as Palau, Fiji and Tonga. The largest and most populous country in Oceania is Australia, with Sydney being the largest city of both Oceania and Australia.
The first settlers of Australia, New Guinea, and the large islands just to the east arrived more than 60,000 years ago. Oceania was first explored by Europeans from the 16th century onward. Portuguese navigators, between 1512 and 1526, reached the Tanimbar Islands, some of the Caroline Islands and west Papua New Guinea.
On his first voyage in the 18th century, James Cook, who later arrived at the highly developed Hawaiian Islands, went to Tahiti and followed the east coast of Australia for the first time.
The arrival of European settlers in subsequent centuries resulted in a significant alteration in the social and political landscape of Oceania.
Puncak Jaya in Papua is the highest peak in Oceania at 4,884 metres.
Most Oceanian countries have a parliamentary representative democratic multi-party system, with tourism being a large source of income for the Pacific Islands nations.