Kilauea Hawaii Essay Example For Students

Kilauea Hawaii Essay Kilauea Hawaii consists of a string of islands, or an archapelago. Kilauea islocated on one of these islands, the central Hawaii island. Kilauea is one ofthe worlds most active volcanic craters. Craters are formed either by themassive collapse of material during volcanic activity, by unusually violentexplosions, or later by erosion during dormancy (Comptons). It is situated onthe southeastern slope of the great volcanic mountain Mauna Loa. Its elevationis 1111 m (3646 ft.) above sea level. The crater has an area of about 10 sq. km., which forms a great cavity in the side of the mountain. Volcanic activityrecently has been restricted to an inner crater called Halemaumau. Halemaumaumeasures more than 900 m (about 3000 ft.) across and has a depth of about 400 m(about 1300 ft.). Kilauea has erupted at least once a year since 1952. Thevolcano spews an average of 525,000 cubic yards of lava a day and by 1995 hadadded about 500 acres of new land to the island (Encarta ?98). By June 1989,it had destroyed the visitors center at the national park, a stretch of KalapanaHighway, and more than 65 houses by 1990. Kilauea is located on a hot spot underthe island, and the magma is thought to come from a depth of at least 50 km. below the surface. A hot spot is an area of volcanic activity near the center oftwo lithospeheric plates. Normally, lava streams constantly into the floor ofthe crater from subterranean sources which either cools and hardens, oraccumulates until it drains off into other subterranean passages. When greatervolcanic activity occurs, the lava is subjected to sudden changes of level,where it may escape from vents on the lower slope toward the sea. Kilauea isclassified as a shield volcano. Shield volcanoes have a low, broad profilecreated by highly fluid basalt flows that spread over wide areas. The fluidbasalt usually only builds a cone around seven degrees steep. Over thousands ofyears though, these cones can reach massive size, which is shown in the HawaiianIsland volcanoes. The Hawaiian Islands are composed of shield volcanoes, thathave been built up from the sea floor. If measured from sea floor level, some ofthe Hawaiian volcanoes are the worlds largest mountains in terms of both hei ghtand volume (Comptons). In the 20th century, major flows occurred in 1920 and1921, 1950, 1955, 1959, 1965, and 1969. The current eruption cycle, thelongest-running in modern Hawaiian history, began on January 3, 1983 (Encarta).