Islands of Oceania, volcanic, continental, and coral
Oceania is the name of the largest cluster of large and small islands on our planet in the western and central Pacific. The islands of Oceania cover about 1.3 million square kilometers of the Earth’s surface, and there are almost 7 thousand of them, big and small.
The areas of the islands of Oceania
Traditionally, geographers, historians, and ethnographers divide the islands of Oceania into three groups: Melanesia with the largest island New Guinea, Micronesia, and Polynesia with New Zealand, the second largest island in Oceania.
Oceania’s island region Melanesia (“black island”)
Melanesia is located in western Oceania and, in addition to New Guinea, it includes the Bismarck and Louisiana archipelagos, as well as the D’Antcastro Islands, the Santa Cruz Islands, the Solomon Islands, the New Herbid Islands, New Caledonia, the Fiji Islands, the Loyalty Islands, and several others.
The main share of Melanesian territory falls on the island of New Guinea. It owns 829 out of 969 thousand square kilometers, occupied by this area of Oceania islands.
Oceania’s island region Polynesia (“multisland”)
Polynesia stretches from the southwest to the east of Oceania. The largest islands in Polynesia are New Zealand, Hawaii, Tonga, Samoa, Wallis, Tokelau, Horn, Cook Islands, Tuvalu, Tubua’i, Society, Marquesas Islands, and Easter Island.
New Zealand accounts for 265,000 square kilometers of the total Polynesian area, Hawaii for 17,000, and Hawaii for 9,000.
Ocean Island Region Micronesia (“small island area”)
Micronesia is located in northwestern Oceania. The total area of its islands is only 2.6 thousand square kilometers, but scattered these tiny islands in the ocean area of about 14 million square kilometers.
The main island groups in Micronesia are the Marshall Islands, the Caroline Islands and the Mariana Islands, as well as the Gilbert Islands.
Islands of Oceania by type of origin
The islands of Oceania differ in their origin and according to this feature they are commonly divided into four types: volcanic, coral or atoll (biogenic), continental, and geosynclinal.
Volcanic Islands of Oceania
Volcanic islands in Oceania are the tops of dormant or active underwater volcanoes. They include islands ranging in size from ten square kilometers to several thousand and are the main type of islands in Oceania.
The most famous of the volcanic islands are Hawaii, Easter Island, Tahiti and Samoa.
Coral Islands of Oceania (Biogenic)
Whole colonies of small marine animals, corals, usually live in the shallow waters of the ocean. Over the centuries, as corals die off, their skeletons cover the ocean floor, press and form rock. Over time, coral reefs and entire islands appear above the surface of the water, and if coral deposits occurred along the contour of the vent of an underwater volcano, atolls appear – coral islands with a lagoon in the center.
There are hundreds of coral islands (atolls) in Oceania, both solitary and forming entire archipelagos. These are the Caroline Islands, the Mariana Islands, the Marshall Islands, as well as the Gilbert and Tuamotu Islands. The largest atoll in Oceania is Kwajalein. It covers an area of 2,300 square kilometers (including the area of the lagoon) and belongs to the Marshall Islands archipelago.
The mainland islands of Oceania
The mainland islands of Oceania were once part of the mainland and became islands as a result of crustal movement. For example, New Guinea is separated from mainland Australia only by a strait whose bottom was once land, while New Zealand is part of what was once a vast continent that encompassed both Australia and Antarctica.
The mainland islands of Oceania comprise 90 percent of its territory. There are lowlands, mountain systems, and extended mountain plateaus.
Geosynclinal islands of Oceania
Geosynclinal islands were formed in areas of the Earth’s transition crust, as a result of tectonic uplift of the ocean floor. They are located in the western part of Oceania and have an elongated shape. The largest geosynclinal island in Oceania is New Caledonia.
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