HAWAII VOLCANOES NATIONAL PARK

national park encompassing a volcanic area along the southeastern shore of Hawaii Island, U.S., southwest of Hilo. Established in 1961 and formerly a part of Hawaii National Park, it occupies an area of 359 square miles (930 square km) and includes two active volcanoesMauna Loa and Kilauea25 miles (40 km) apart. It was designated a World Heritage site in 1987. Mauna Loa, located in the south-central part of the island, is the Earth's largest volcano. Its bulk extends upward about 3 miles (5 km) from the ocean bottom, then rises an additional 2.6 miles (4.2 km) to an elevation of 13,677 feet (4,169 metres) above sea level. Covering half of the island, Mauna Loa is a shield volcano that has erupted 33 times since 1843, its first well-documented eruption. Its summit caldera is approximately 2 by 3 miles (3 by 5 km) in diameter and 600 feet (183 metres) deep. The volcano has been intermittently active, displaying eruptions both in its caldera and from fissures in its flanks. In 1881 a flank lava flow from the northeastern side of the volcano entered the outskirts of the city of Hilo. In 1950 a lava flow from the volcano's southwestern rift zone reached the ocean in less than 3 hours, covering the distance at a speed of 5.8 miles (9.3 km) per hour. Mauna Loa's most recent eruption was in 1984, following earthquake activity beneath the volcano. Kilauea lies east of Mauna Loa and is considered to be the Earth's most active volcano; it is also Hawaii's youngest. It covers about one-seventh of the island of Hawaii (southeast) and rises to about 4,078 feet (1,243 metres) above sea level. It also is a shield volcano, with a summit caldera about the same size as Mauna Loa's but not quite as deep. Halemaumau crater, located within Kalauea's caldera, is the volcano's most active vent. In 1924 a series of steam explosions ejecting ash and blocks of lava followed the abrupt draining away of Halemaumau's active lava lake. Sporadic eruptions at Halemaumau crater followed, including a four-month eruption in 1952. Subsequent eruptions of Kilauea have occurred primarily in the volcano's east rift zone; these became continuous beginning in 1983. First the Puu Oo vent, located southeast of Kilauea's caldera on the national park's boundary, produced lava fountains reaching heights of 1,540 feet (470 metres) into the air. Then in 1986 the eruption shifted 2 miles to the northeast of Puu Oo to the new Kupaianaha vent, from which a quiet effusion of lava continued to flow and eventually reached the ocean; in 1990 lava buried the entire historic community of Kalapana. In 1992 the flow of lava shifted back to the Puu Oo vent, where a cinder cone had previously formed. After the collapse of the cone, lava from Puu Oo, flowing through a 7-mile- (11-km-) long lava tube system, reached the ocean in 1997. This eruption continued into 1998, by which time more than 570 acres (230 hectares) of new land had been added to Hawaii's southern shore. Other highlights of the national park are Kau Desert, a region of unusual lava formations in the rain shadow of Kilauea; Mauna Loa Trail, which wends its way to that volcano's peak from Kilauea; a tree-fern forest, a dense tropical area watered by nearly 100 inches (2,500 mm) of rainfall annually; and the museum at the park headquarters. The area abounds with tropical birds. Introduced species include the mongoose, wild goat and pig, and pheasant and quail.