Kīlauea is a shield volcano in the Hawaiian Islands, the most active of the five volcanoes that together form the island of Hawaiʻi. Located along the southern shore of the island, the volcano, at 300,000 to 600,000 years old, 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 125 km (78 mi) east and the other 35 km (22 mi) west, as an active fault line of unknown depth moving vertically an average of 2 to 20 mm (0.1 to 0.8 in) 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.

Kīlauea's current eruption dates back to January 3, 1983, and is by far its longest-lived historical period of activity, as well as one of the longest-lived eruptions in the world; as of January 2011, the eruption has produced 3.5 cubic kilometres (0.84 cu mi) of lava and resurfaced 123.2 km2 (48 sq mi) of land.

Kīlauea's high state of activity has a major impact on its mountainside ecology where plant growth is often interrupted by fresh tephra and drifting volcanic sulfur dioxide, producing acid rains particularly in a barren area south of its southwestern rift zone known as the Kaʻū Desert. Nonetheless, wildlife flourishes where left undisturbed elsewhere on the volcano and is highly endemic thanks to Kīlauea's (and the island of Hawaiʻi's) isolation from the nearest landmass. Historically, the five volcanoes on the island were considered sacred by the Hawaiian people, and in Hawaiian mythology Kīlauea's Halemaumau Crater served as the body and home of Pele, goddess of fire, lightning, wind, and volcanoes. William Ellis, a missionary from England, gave the first modern account of Kīlauea and spent two weeks traveling along the volcano; since its foundation by Thomas Jagger in 1912, the Hawaiian Volcano Observatory, located at Kīlauean caldera rim, has served as the principal investigative and scientific body on the volcano and the island in general. In 1916 a bill forming the Hawaii Volcanoes National Park was signed into law by Woodrow Wilson; since then the park has become a World Heritage Site and a major tourist destination, attracting roughly 2.6 million people annually.

en.wikipedia.org/wiki/K%C4%ABlauea