Pacific Islands

I

Introduction Print this section Pacific Islands or Oceania, the more than 25,000 islands and islets of 25 nations and territories spread over the western and central Pacific Ocean. Although the Pacific Islands are scattered across millions of square kilometers, their total land area is just 1,261,456 sq km (487,051 sq mi)—slightly larger than South Africa, slightly smaller than Peru, and four-fifths the size of Alaska. The islands of New Guinea, New Zealand, and Hawaii constitute 93 percent of the land area, while the remaining thousands of islands have a total land area of 89,339 sq km (34,494 sq mi), slightly less than the American state of Indiana. New Guinea, shared by the Indonesian province of Papua (formerly Irian Jaya) and the nation of Papua New Guinea, is the second largest island in the world, after Greenland. New Zealand’s South Island and North Island, Oceania’s next largest islands, are the world’s 12th and 14th largest islands, respectively.

II Melanesia, Micronesia, and Polynesia Print this section The Pacific Islands are usually divided into three subregions: Melanesia (the prefix mela, meaning dark or black, refers to the dark complexion of many Melanesian people), Micronesia (the prefix micro, meaning small, refers to the small size of Micronesia’s islands and atolls), and Polynesia (the prefix poly, meaning many, refers to the many islands of Polynesia). Melanesia stretches in a 5600-km (3500-mi) arc off the northern and eastern coast of Australia. From northwest to southeast, Melanesia includes New Guinea, lying just north of Australia; the Bismarck Archipelago, belonging to Papua New Guinea; smaller archipelagos of Papua New Guinea; the Solomon Islands, some of which belong to Papua New Guinea but most of which are part of the nation of Solomon Islands; the many islands of the nation Vanuatu; the islands of New Caledonia and Dependencies, a French territory; and the Fiji Islands (an island nation commonly known as Fiji). The tiny islands and atolls of Micronesia are scattered widely across a large area north of Melanesia and east of Asia. Micronesia has four main island groups. The Caroline Islands lie north of the equator from New Guinea and belong mostly to the Federated States of Micronesia, a self-governing country in free association with the United States. A small portion of the Carolines belongs to Palau, also a self-governing country in free association with the United States. To the north of the Carolines are the Mariana Islands, which make up the Commonwealth of the Northern Mariana Islands, a self-governing U.S. commonwealth, and Guam, an unincorporated U.S. territory. To the east of the Marianas are the Marshall Islands, an island group and republic in free association with the United States. Southeast of the Marshalls is the nation of Kiribati, which straddles the equator. The tiny nation of Nauru, a single island west of Kiribati, is also counted as part of Micronesia. Micronesia’s islands are so small that their land area totals just 3240 sq km (1250 sq mi). Even among the smaller islands of Oceania—that is, Oceania excluding New Guinea, New Zealand, and Hawaii—Micronesia makes up just 3.6 percent of the total land mass.

Polynesia, lying in the central and southern Pacific, encompasses a vast triangle stretching east from Melanesia and Micronesia. Polynesia is larger than both Melanesia and Micronesia combined. The southwestern tip of the Polynesian triangle is the nation of New Zealand, lying southeast of Australia and far south of the tropic of Capricorn. The southeastern tip is Easter Island, part of Chile lying just south of the tropic of Capricorn three-fourths of the distance from Australia to South America. The triangle’s northwestern tip is Hawaii, straddling the tropic of Cancer halfway between North America and Asia. These three tips, however, are outliers: Most of Polynesia is clustered just east of Melanesia south of the equator. From north to south, the Polynesian islands immediately east of Melanesia form the nation of Tuvalu; Wallis and Futuna, a French territory north of Fiji; and the nation of Tonga. Farther east, from north to south, are Tokelau, a territory of New Zealand; the independent nation of Samoa (formerly Western Samoa); American Samoa, a U.S. territory; Niue, a self-governing island in free association with New Zealand; and the Cook Islands, a self-governing island group also in free association with New Zealand. Still farther east lie the five archipelagos of the French territory French Polynesia: the Austral Islands, the Society Islands (with well-known Tahiti and Bora-Bora), the Tuamotu Archipelago (including the Gambier Islands), and the Marquesas Islands. Beyond French Polynesia is Pitcairn Island, a dependency of the United Kingdom. Oceania is sometimes defined to include Australia, but because of Australia’s continental size and its distinct geography, climate, and cultures it is more often considered a separate region of the world. Similarly, the Philippine, Indonesian, and Japanese archipelagos, which border Melanesia and Micronesia, bear a greater resemblance to the rest of Asia than the Pacific Islands do. Other, smaller island groups on the far northern and eastern edges of the Pacific (for example, the Aleutian Islands of Alaska and the Galápagos Islands of Ecuador) are usually classified with the nearby regions of the Western Hemisphere. III The Natural Environment Print this section The islands of the Pacific are often classified according to their altitudes as high or low islands. A Types of Islands: High Islands High islands are further classified as either continental or oceanic. The continental high islands were once part of the eastern edge of the Australian and Asian continents and are composed of substances similar to their former continents: ancient metamorphic rocks and sediments as well as rocks such as schist, gneiss, clay, and sandstone. Continental islands include New Guinea and most islands of Melanesia, which together account for more than three-fourths of Oceania’s land area. The oceanic high islands, sometimes called volcanic islands, are divided from the continental high islands by a north-south boundary of rock formations beneath the sea called the Andesite line. The oceanic islands are composed of volcanic materials that were forced upward through cracks, or fissures, in the ocean floor and from newly deposited sediments. The islands, then, are merely the tops of undersea mountains. Typically, the mountains (and thus the islands) extend in curving chains. These high oceanic islands are common in Polynesia and Micronesia. The island of Hawaii, in Polynesia, contains the peaks Mauna Loa and Mauna Kea, which are considered the world’s largest mountains in terms of mass and height above the ocean floor. Although both peaks rise less than 4300 m (14,000 ft) above sea level, they rise about 10,000 m (33,000 ft) from the sea floor. Other examples of high oceanic islands in Polynesia include the Samoas, Tahiti and the Marquesas, and Rarotonga in the Cook Islands. In Micronesia, Kosrae and Pohnpei of the Caroline Islands are examples.