Kīlauea
Kīlauea is an active shield volcano in the Hawaiian Islands. It is located along the southeastern shore of Hawaii Island. The volcano is between 210,000 and 280,000 years old and grew above sea level about 100,000 years ago. Since the islands were settled, it has been the most active of the five volcanoes that together form the island and among the most active volcanoes on Earth. The most recent eruption began in December 2024, with episodic lava fountains and flows continuing into 2026.
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. Kīlauea has a large, fairly recently formed caldera at its summit and two active rift zones, one extending east and the other west. An active fault of unknown depth moves vertically an average of per year.
Between 2008 and 2018, Halemaʻumaʻu, a pit crater located within Kīlauea's summit caldera, hosted an active lava lake. Kīlauea erupted nearly continuously from vents on its eastern rift zone between January 1983 and April 2018, causing major property damage, including the destruction in 1990 of the towns of Kalapana and Kaimū along with the community's renowned black sand beach.
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 eruptive fountains that sent rivers of lava 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 destroyed the communities of Kapoho, Vacationland Hawaii, and most of the Kapoho Beach Lots. The County of Hawaii reported that 716 dwellings were destroyed. Concurrent with the activity downrift in lower Puna, the lava lake within Halemaumau 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. Since 2020, several eruptions have occurred within the enlarged Halemaʻumaʻu crater from the 2018 collapse events as well as along the volcano's southwest and east rift zones.
Background
Kīlauea is a Hawaiian word that means "spewing" or "much spreading", referring to its frequent outpouring of lava. Its earliest lavas date back to its submarine preshield stage. Samples were recovered by remotely operated underwater vehicles; samples of other flows were recovered as core samples. Lavas younger than 1,000 years old cover 90 percent of the volcano's surface. The oldest exposed lavas date back 2,800 years.Radiocarbon and paleomagnetic dating identified a major eruption of Kīlauea around 1410, the first to be mentioned in Native Hawaiians' oral history. Western contact and written history began in 1778. The first documented eruption of Kīlauea came in 1823 with repeated eruptions thereafter. Most occurred at the volcano's summit or its eastern rift zone, and were prolonged and effusive. The geological record shows that pre-contact explosive activity was common; in 1790 one such eruption killed more than 400 people, making it the deadliest volcanic eruption in what became the United States.
Kīlauea's eruption from January 3, 1983, to 2018 was by far its longest-duration 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 even larger ʻAilāʻau eruption of 1410 lasted about 60 years, ending in 1470 with an estimated volume of.
Kīlauea's 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 left undisturbed elsewhere on the volcano and is highly endemic thanks to Kīlauea's isolation from the nearest continental landmass. Historically, the island's five volcanoes were considered sacred by the Hawaiian people, and in Hawaiian mythology Halemaumau served as the body and home of Pele, goddess of fire, lightning, wind, and volcanoes.
English missionary William Ellis gave the first modern account of Kīlauea and spent two weeks exploring the volcano. Since its foundation by Thomas Jaggar in 1912, the Hawaiian Volcano Observatory, for many years located on the rim of Kīlauea's summit caldera, has served as the principal investigative and scientific body on the volcano and the island. In 1916, a bill forming Hawaii Volcanoes National Park was signed into law by President Woodrow Wilson. The park is a World Heritage Site and a major tourist destination, attracting roughly 2.6 million visitors annually.
Geology
Setting
Like all Hawaiian volcanoes, Kīlauea was formed as the Pacific tectonic plate moved over the Hawaiian hotspot in the Earth's underlying mantle. Hawaii island volcanoes are the most recent evidence of this process that, over 70 million years, has produced the -long Hawaiian–Emperor seamount chain. The prevailing view is that the hotspot has been largely stationary within the planet's mantle for much of the Cenozoic Era. However, while the Hawaiian mantle plume is well understood and extensively studied, the nature of hotspots themselves remains uncertain.Kīlauea is one of five subaerial volcanoes that make up the island of Hawaii, originated from the Hawaiian hotspot. The oldest volcano on the island, Kohala, is more than a million years old, while Kīlauea, the youngest, is between 300,000 and 600,000 years of age. Kamaʻehuakanaloa, on the island's flank, is younger and has yet to breach the surface. Thus Kilauea is the second youngest volcano in the Hawaiian–Emperor seamount chain, a chain of shield volcanoes and seamounts extending from Hawaii to the Kuril–Kamchatka Trench in Russia.
Kīlauea started as a submarine volcano, gradually growing larger and taller via underwater eruptions of alkali basalt lava before emerging from the sea with a series of explosive eruptions about 50,000 to 100,000 years ago. Since then, the volcano's activity has produced a continual stream of effusive and explosive eruptions of roughly the same pattern as its activity since records began to be kept.
Hawaii island's oldest volcano, Kohala, experienced almost 900,000 years of activity before going extinct. Eruptions and explosive activity will make Kīlauea taller, build up its rift zones, and fill and refill Kaluapele.
Structure
Kīlauea has been active throughout its history. Cinder cones, satellite shields, lava tubes, and other eruptive structures are present, evidence of its recent activity. Since 1918, Kīlauea's longest pause lasted 18 years between 1934 and 1952. The bulk of Kīlauea consists of solidified lava flows, intermixed with volcanic ash and tephra produced by lower-volume explosive eruptions. Much of the volcano is covered in historical flows, while 90 percent of its surface is from the last 1,100 years. Much of its bulk remains underwater; its subaerial surface is a gently sloping, elongate, decentralized shield with a surface area of approximately, making up 13.7 percent of the island's total surface area.Kīlauea lacks topographical prominence, appearing only as a bulge on the southeastern flank of Mauna Loa. Native Hawaiians and early geologists considered it an active satellite of its host. However, lava analysis shows that the two have separate magma chambers. Nonetheless, high activity at one volcano roughly coincides with low activity at the other. When Kīlauea lay dormant between 1934 and 1952, Mauna Loa became active, and when the latter remained quiet from 1952 to 1974, the reverse was true. This is not always the case; the 1984 eruption of Mauna Loa started during an eruption at Kīlauea, but had no discernible effect on the Kīlauea eruption, and the ongoing inflation of Mauna Loa's summit, indicative of a future eruption, began the same day as new lava flows at Kīlauea's Puu Ōō crater. In 2002, Kilauea experienced a high-volume effusive episode at the same time that Mauna Loa began inflating. This unexpected communication is evidence of crustal-level interactions between them. Geologists suggested that "pulses" of magma entering Mauna Loa's deeper magma system may have increased pressure inside Kīlauea and triggered the concurrent eruptions. Mauna Loa began erupting on November 27, 2022, during Kīlauea's ongoing eruption, the first time since 1984 that both volcanoes were simultaneously erupting.