Oceania
Thousands of islands scattered across a wide area of the Pacific Ocean are grouped together under the name of Oceania. The region is generally divided into three major cultural areas—Melanesia, Micronesia, and Polynesia. Sometimes a fourth area called Australasia is also considered to be a part of Oceania. This area, which includes Australia, New Zealand, and the island of New Guinea, somewhat overlaps the others. (See also Australia and New Zealand.)
Pacific islands outside these groups are generally not considered to be part of Oceania. Some, such as those of Indonesia, Taiwan, the Philippines, and Japan, have close ties to Asia. Others, such as the Aleutians, are extensions of North America.
The islands of Melanesia form a great arc north and east of Australia. Melanesia includes the political units of Papua New Guinea, Solomon Islands, Vanuatu, New Caledonia, and Fiji. Papua New Guinea occupies the eastern half of the island of New Guinea. The name Melanesia means “black islands” and refers to the dark skin of the people who live there.
East of the Philippines and mostly north of the equator are the islands of Micronesia. Micronesia means “small islands.” The region stretches from Palau in the west to Kiribati in the east through the Mariana Islands (including Guam), the Federated States of Micronesia, the Marshall Islands, and Nauru.
The islands of Polynesia lie generally east of Micronesia and Melanesia. Polynesia means “many islands” in the Greek language. The political units of Polynesia include Samoa (formerly called Western Samoa), American Samoa, Cook Islands, French Polynesia, Easter Island, Tonga, Wallis and Futuna, Tuvalu, and Hawaii (an island group which is one of the states of the United States). New Zealand is often included in Polynesia because that country's Maori people have a Polynesian cultural background.
The majority of Oceania's islands are clustered in the west-central Pacific Ocean, with a very few in the east. Almost all are in the tropical zone between the Tropic of Cancer and the Tropic of Capricorn. Although they range over a vast expanse of ocean, they take up a relatively tiny amount of land. Not counting New Zealand, New Guinea, and Australia, their combined land area is only about 42,000 square miles (109,000 square kilometers). More than 100 of the world's countries are larger than that. There are so many tiny islands in Oceania that their total number is still uncertain.
Most islands of Oceania are on or near the Pacific plate. A plate is a rigid section of the Earth's crust that underlies continents and oceans and moves in relation to other plates. Most of the world's earthquakes take place along the edges of the Pacific plate. Undersea earthquakes create waves of water called tsunamis that can strike the shore with destructive force.
The movement of plates also causes volcanic activity. Because there are so many active volcanoes around the boundary of the Pacific plate, it is often called the ring of fire. The islands of Hawaii are the tops of an undersea volcanic ridge, from which molten lava erupts through the Mauna Loa and Kilauea volcanoes. Kilauea is the world's largest active volcano.
The islands of Oceania may be classified as either continental or oceanic. The continental islands are parts of the same landmasses that make up the continents of Australia and Asia. Much of Melanesia consists of continental islands, which tend to be larger than the islands farther east. Many continental islands have high terrain. The slopes are steep because of heavy rains that wear away rock and soil from the mountainsides.
The islands in the central and eastern Pacific are called oceanic islands because they rise directly from the ocean floor. Most of the islands of Polynesia and Micronesia are of the oceanic type. Some oceanic islands were created by volcanic activity and are mountainous. The peak of Mauna Kea, on the island of Hawaii, stands 13,796 feet (4,205 meters) above sea level.
Other oceanic islands were built up from the limestone secretions of countless coral animals. They are called coral islands, though they may rest upon an underwater base of volcanic stone. Atolls are coral islands made up of a ring of land or islets (small islands) surrounding a shallow lagoon. The largest atoll in the world is Kwajalein in the Marshall Islands, which has 90 islets around a lagoon of about 650 square miles (1,683 square kilometers). Atolls often rise only a few feet above sea level, but not all coral islands are low. Sometimes movement in the Earth's crust pushes coral limestone upward. Part of Guam and many of the islands of Tonga consist of raised coral formations.
Coral is also found in formations called reefs that surround even high volcanic islands. Coral reefs shelter sea creatures and protect island shorelines from erosion.
As a tropical region, Oceania has mostly warm weather with very little temperature variation from season to season. Sea breezes cool coastal regions.
The main source of moisture is the ocean. Many parts of the western Pacific receive more than 80 inches (200 centimeters) of rain each year. Oceania's rainiest areas are on mountainous islands where slopes direct moist winds upward. This cools the air, causing clouds to form and rain to fall. No place on the surface of the Earth is wetter than Mount Waialeale on Kauai Island, Hawaii, which gets 460 inches (1,168 centimeters) of rain per year. By contrast, low-lying areas not far way receive less than 20 inches (50 centimeters) of rain per year.
When humidity is high, strong circular storms called typhoons can develop over water. (The same kind of storm is known as a hurricane in the Atlantic.) Every few years a current called El Niño flows in the Pacific Ocean. El Niño has been known to bring severe drought to the islands of the western Pacific.
The native plants of most islands in Oceania grew originally in Asia and spread eastward by way of Indonesia and New Guinea. Islands close to the mainland tend to have more kinds of plants than islands far out to sea. A plant establishing itself in a new area has to adapt to local conditions, such as the constant salt spray on small islands. Shrubs and vines are found near the oceans, and mangroves grow densely in salt marshes. Coconut trees flourish on coral islands. Further inland banana trees, breadfruit trees, and papaya plants are found. Rain forests are a feature of many high islands. However, human activity has disturbed them in many places. Taro is a native plant that is still widely grown for food.
Migratory ducks and seabirds such as frigate birds, albatrosses, and boobies can be found nearly everywhere. Of the region's land birds, many are found on one island only and others have very limited ranges. Most islands have some snakes and lizards, though crocodiles are limited to the western islands. Except for New Guinea, the islands of Oceania can count only bats and rats as truly native mammals. Other mammals, such as pigs, dogs, poultry, goats, deer, and cattle, were brought into the area by early islanders or by Europeans.
The marine life in Oceania is an essential resource for humans. Reefs and lagoons shelter many kinds of fish as well as lobsters, shrimps, snails, eels, octopuses, and turtles. Bigger sport fish such as swordfish and marlin lurk in deeper waters, as do whales, porpoises, and sharks. There are more insects, including centipedes, cockroaches, and mosquitoes, than any other kind of island wildlife.
In all the vast areas of Oceania (not including Australia), there were only about 12 million people at the start of the 21st century. The country with the most people is Papua New Guinea in Melanesia, but New Zealand, Hawaii, and Tonga, all of which are in Polynesia, also have comparatively large populations. Micronesia is the region with the fewest people.
Farming is the traditional occupation of Melanesians. Pig raising is also widespread. In addition to beach dwellers there are also groups who live in the “bush”—the inland portions of the larger islands. Melanesian arts include face masks, sculptured figures, and body scarring.
Micronesians are traditionally canoeists, fishers, and traders. They usually live close to the shorelines of their small islands. Artisans make mats, shell ornaments, and woven cloth.
Polynesians are farmers and fishers. They have developed elaborate religious rites and codes of behavior. Artistic creativity takes the form of tattooing and of sculpture in wood and stone.
In all three regions of Oceania, coconut products such as copra (dried meat) and coconut oil are sold to the rest of the world in large quantities. Fish and other sea creatures are also of widespread economic importance. Sugarcane is grown in Fiji and in Hawaii. On the Solomon Islands and Vanuatu, much timber is harvested commercially. Gold and oil are found in Papua New Guinea, while nickel is mined on New Caledonia. The mining of phosphates has long been important on Nauru, but by the start of the 21st century the deposits had almost run out.
Traditional farmers on many islands burn trees and use the smoldering ashes to nourish crops. After harvesting, a new section of forest is chopped down and burned and the process is repeated. This cycle is called shifting cultivation, or slash-and-burn agriculture. Crops that are commonly raised for local use include taro, sweet potato, bananas, and breadfruit.
Tourism is an important source of income in many areas. For many years people have come to the “South Sea islands” to swim, fish, or lie on the beach. Many governments also depend on aid from countries that are more developed economically.
Melanesia was the first region of Oceania to be settled. Speakers of Papuan languages may have occupied New Guinea, which was then joined to Australia, as early as 50,000 years ago. Papuan peoples became farmers, growing sugarcane and root crops, as early as 9,000 years ago. Seagoing Austronesian people moved into the areas north of New Guinea about 4,000 years ago. As the islanders developed skill in navigation and boat building, they settled the more remote islands. By the time the Polynesian Maori people reached New Zealand in about AD 800, settlement of the Pacific islands was just about complete.
In 1521 the Portuguese navigator Ferdinand Magellan became the first European to explore the region. Spanish, Dutch, and English voyagers followed. By 1779, when the great English explorer James Cook was killed in Hawaii, all the major island groups were known to the outside world.
Sustained contact with Europe did not come until the late 18th and 19th centuries, when trade increased. France and Great Britain claimed the first colonies in the 1840s, and Germany followed. The United States took control of Guam, Hawaii, and the eastern islands of Samoa (now American Samoa) in the 1890s.
Along with Christian missionaries, the colonial powers brought about changes that would transform traditional life in Oceania forever. The colonizers carried with them diseases and weapons formerly unknown to the land, causing many deaths among the native population. The outsiders also brought new languages and food crops. They discouraged local warfare and encouraged permanent villages. Tribal groups that had always been on the move settled down in relative safety.
Starting with the Japanese attack on Pearl Harbor in Hawaii in 1941, many parts of Oceania became battlefields. The islands of Micronesia in particular were hit hard by the struggle between Japan and the Allies in World War II. At the end of the war, many of the islands north of the equator that had been ruled by Japan were put under U.S. control by the United Nations.
Aside from New Zealand, which became a self-governing British dominion in 1907, and Hawaii, which became a U.S. state in 1959, all areas of Oceania were under foreign control until 1962. In that year Samoa (then called Western Samoa) achieved full independence. Many other new countries emerged later. At the beginning of the 21st century, however, many islands remain under some form of foreign control. The Northern Mariana Islands, American Samoa, and Guam are associated with the United States. French Polynesia, Wallis and Futuna, and New Caledonia are associated with France. Among the other places under foreign control are Easter Island, which is ruled by Chile, and the Cook Islands, which are associated with New Zealand.
