| "The South Pacific are comprised of island nations situated throughout the Pacific Ocean.A low ribbon of reef and sand encircling a lagoon, an atoll is the very soul of Pacific romance." John Dyson (1982) Micronesia contains four great archipelagos: the Marshalls, Gilberts, Carolines, and Marlanas, largely north of the equator. Ot Micronesia's thousands of islands, 125 are uninhabited. The largest volcanic islands are Guam (209 square miles), Babeldaob in the Republic of Palau (153 square miles), and Pohnpei (129 square miles). In lagoon area, Kwajalein is the world's largest atoll (839 square miles), while in land area Christmas Island (150 square miles) is the biggest of the coral islands. There is great geologic variation in Micronesia's islands. Some are high with volcanic peaks, others low islands of sand and coral. All of the Marshalls and Gilberts are coral atolls or islands. In the Northern Marianas, Micronesia's only active volcanoes erupt. Nauru and Banaba and half of Guam are uplifted atolls. The Caroline Islands include both volcanic and coral types. Kosrae, Pohnpei, and Weno (Chuuk) are high volcanic islands. Guam and Palau are exposed peaks of an undersea ridge stretching between Japan and New Guinea, volcanic in origin but partly capped with limestone. Yap is an uplifted section of the Asian continental shelf, which floated away. This surprising variety of landforms makes Micronesia a geologist's paradise. Tectonic Plates The westernmost islands of Micronesia flank some of the deepest waters on earth. The 4.2-mile-deep Marianas Trench is the western edge of the vast Pacific Plate, the only one of earth's six plates that doesn't bear a continent. As this plate gets wedged under the Philippine Plate just east of the Marianas, volcanoes erupt along this section of the Pacific "Ring of Fire." The clashing plates have uplifted parts of Guam, Rota, Tinian, and Saipan. | |
|
