Kīlauea

Kīlauea is a currently active shield volcano in the Hawaiian Islands, and the most active of the five volcanoes that together form the island of Hawaii. Located along the southern shore of the island, the volcano is between 300,000 and 600,000 years old and emerged above sea level about 100,000 years ago. It is the second youngest product of the Hawaiian hotspot and the current eruptive center of the Hawaiian–Emperor seamount chain. Because it lacks topographic prominence and its activities historically coincided with those of Mauna Loa, Kīlauea was once thought to be a satellite of its much larger neighbor. Structurally, Kīlauea has a large, fairly recently formed caldera at its summit and two active rift zones, one extending 125km east and the other 35km west, as an active fault of unknown depth moving vertically an average of 2to per year.Kīlauea's eruptive history has been a long and active one; its name means "spewing" or "much spreading" in the Hawaiian language, referring to its frequent outpouring of lava. The earliest lavas from the volcano date back to its submarine preshield stage, samples having been recovered by remotely operated underwater vehicles from its submerged slopes; samples of other flows have been recovered as core samples. Lavas younger than 1,000 years cover 90 percent of the volcano's surface. The oldest exposed lavas date back 2,800 years. The first well-documented eruption of Kīlauea occurred in 1823 (Western contact and written history began in 1778), and since that time the volcano has erupted repeatedly. Most historical eruptions have occurred at the volcano's summit or its eastern rift zone, and are prolonged and effusive in character. The geological record shows, however, that violent explosive activity predating European contact was extremely common, and in 1790 one such eruption killed over 80 warriors; should explosive activity start anew the volcano would become much more of a danger to humans. Kīlauea's current eruption dates back to January 3, 1983, and is by far its longest-duration historical period of activity, as well as one of the longest-duration eruptions in the world; as of January 2011, the eruption has produced 3.5km3 of lava and resurfaced 123.2km2 of land.