Kilauea Hawaii consists of a string of islands, or an archapelago. Kilauea is
located on one of these islands, the central Hawaii island. Kilauea is one of
the world’s most active volcanic craters. Craters are formed either by the
massive collapse of material during volcanic activity, by unusually violent
explosions, or later by erosion during dormancy (Comptons). It is situated on
the southeastern slope of the great volcanic mountain Mauna Loa. Its elevation
is 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 activity
recently has been restricted to an inner crater called Halemaumau. Halemaumau
measures 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. The
volcano spews an average of 525,000 cubic yards of lava a day and by 1995 had
added 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 Kalapana
Highway, and more than 65 houses by 1990. Kilauea is located on a hot spot under
the 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 of
two lithospeheric plates. Normally, lava streams constantly into the floor of
the crater from subterranean sources which either cools and hardens, or
accumulates until it drains off into other subterranean passages. When greater
volcanic 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 is
classified as a shield volcano. Shield volcanoes have a low, broad profile
created by highly fluid basalt flows that spread over wide areas. The fluid
basalt usually only builds a cone around seven degrees steep. Over thousands of
years though, these cones can reach massive size, which is shown in the Hawaiian
Island volcanoes. The Hawaiian Islands are composed of shield volcanoes, that
have been built up from the sea floor. If measured from sea floor level, some of
the Hawaiian volcanoes are the worlds largest mountains in terms of both height
and volume (Comptons). In the 20th century, major flows occurred in 1920 and
1921, 1950, 1955, 1959, 1965, and 1969. The current eruption cycle, the
longest-running in modern Hawaiian history, began on January 3, 1983 (Encarta).