Kīlauea ( , ) is an active shield volcano in the Hawaiian Islands. Located along the southeastern shore of Hawai'i Island, 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 the island of Hawaii. Kīlauea is also one of the most active volcanoes on Earth, with the most recent eruption occurring in September 2023 when multiple vents erupted lava within the volcano's summit caldera.
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 east and the other west, as an active fault of unknown depth moving vertically an average of 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 with vigorous eruptive 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, nearby 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 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. Two years later, Kīlauea erupted between December 2020 and May 2021 again within Halemaʻumaʻu crater, boiling off a water lake that had been growing for more than a year, and replacing it with a lava lake deep.
Background
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.
Native Hawaiian oral history in conjunction with radiocarbon and paleomagnetic dating places the first documentation of a major eruption of Kīlauea around 1410. Western contact and written history began in 1778, with their first well-documented eruption of Kīlauea in 1823. Since then, the volcano has erupted repeatedly. Most historical eruptions occurred at the volcano's summit or its eastern rift zone, and were prolonged and effusive in character. The geological record shows, however, that violent explosive activity predating European contact was extremely common; in 1790 one such eruption killed more than 400 people, making it the deadliest volcanic eruption in what is now the United States. Should explosive activity start anew, the volcano would become much more of a danger to humans.
Kīlauea's eruption from January 3, 1983, to 2018 was by far its longest-duration historical period of activity in modern times, as well as one of the longest-duration eruptions documented on Earth; as of January 2011, the eruption had produced of lava and resurfaced of land. Centuries prior to this event, the ʻAilāʻau eruption of 1410 lasted about 60 years, ending in 1470 with an estimated volume of .