Kīlauea (US: // KIL-ə-WAY-ə, Hawaiian: [kiːlɐwˈwɛjə]) is an active shield volcano in the Hawaiian Islands. Located along the southeastern shore of the Big Island of Hawaiʻi, the volcano is between 210,000 and 280,000 years old and emerged above sea level about 100,000 years ago. Historically, it is the most active of the five volcanoes that together form Hawaii island. Kīlauea is also one of the most active volcanoes on Earth, and the most recent and currently ongoing eruption began on September 29, 2021, when several vents began to erupt lava within Halemaʻumaʻu, a pit crater in the volcano's summit caldera.
|Elevation||4,091 ft (1,247 m)|
|Prominence||50 ft (15 m)|
|Location||Hawaiʻi, United States|
|Age of rock||210,000 to 280,000 years old|
|Mountain type||Shield volcano, hotspot volcano|
|Volcanic arc/belt||Hawaiian–Emperor seamount chain|
|Last eruption||September 29, 2021 – present|
Kīlauea 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 of unknown depth moving vertically an average of 2 to 20 mm (0.1 to 0.8 in) per year.
Between 2008 and 2018, the pit crater Halemaʻumaʻu hosted an active lava lake. Kīlauea also erupted nearly continuously from vents on its eastern rift zone between January 1983 and April 2018, causing considerable property damage, including the destruction of the towns of Kalapana and Kaimū along with the community's renowned black sand beach, in 1990.
Beginning in May 2018, activity shifted further downrift from the summit to the lower Puna district, during which lava erupted from two dozen vents. The eruption saw vigorous eruptive lava fountains that sent destructive rivers of molten rock into the ocean in three places. The eruption destroyed Hawaii's largest natural freshwater lake, covered substantial portions of Leilani Estates and Lanipuna Gardens, and completely inundated the communities of Kapoho, Vacationland Hawaii, and most of the Kapoho Beach Lots. Lava also filled Kapoho Bay and extended new land nearly a mile into the sea. The County of Hawaii reported that 716 dwellings were destroyed by lava. Concurrent with the activity downrift in lower Puna, the lava lake within Halemaʻumaʻu drained and a series of explosive collapse events occurred at the volcano's summit, with at least one explosion emitting ash 30,000 feet (9,100 m) into the air. This activity prompted a months-long closure of the Kīlauea section of Hawaii Volcanoes National Park. The eruption ended in September 2018. After more than two years of quiescence, Kīlauea erupted again between December 2020 and May 2021 within Halemaʻumaʻu crater, where lava erupted from several vents boiled off a water lake that had been growing within the crater for more than a year, replacing it with a lava lake 229 metres (751 ft) deep.