Lava Beds National MonumentPágina 39 de 51
Lava Lakes: Pools of Molten Rock in Kīlauea, Mauna Loa and Other National Parks
A lava lake is a lake of molten, or later solidified, lava in a crater or depression, formed when a vent or crater partly fills with lava. Most are basaltic. They occur in the summit calderas of shield volcanoes, in other vents of basaltic volcanoes, and sometimes where pāhoehoe flows pool.
Long-lived lava lakes, like those in Halemaʻumaʻu in Kīlauea's caldera, are rare. They last because they have an open connection to a shallow magma chamber, and at Kīlauea the lake's level rises and falls with the pressure in the top of the chamber beneath it.
The lava lake in Halemaʻumaʻu, 9 November 2021. U.S. Geological Survey.
Halemaʻumaʻu’s lava lake on 3 January 2021. U.S. Geological Survey.
Kīlauea
Halemaʻumaʻu, the pit crater in Kīlauea's summit caldera, has held lava lakes again and again:
| Period | Lava lake |
|---|---|
| much of the 1800s, early 1920s | active lake |
| 1920s, early 1930s, 1952, 1967–1968 | during short eruptions |
| 2008–2018 | persistent lake of the long summit eruption, drained when a vigorous eruption on the lower East Rift Zone ended it, and the caldera collapsed |
Rafts of solidified lava floating on the lake show both in a 1917 photograph and in 2021. Elsewhere on Kīlauea, a lake came and went in Puʻuʻōʻō, the East Rift Zone vent active from 1983 to 2018, and one formed in Kīlauea Iki, a crater near the summit, during its 1959 eruption.
Rafts of solidified lava on Halemaʻumaʻu’s lava lakes in 1917 and 2021. U.S. Geological Survey.
Thermal images, September and October 2021: the dark patches are rafts of cooled lava. U.S. Geological Survey.
Halemaʻumaʻu’s lava lake labeled, 30 December 2020. U.S. Geological Survey.
The lava lake in Kīlauea Iki during its 1959 eruption. U.S. Geological Survey.
Mauna Loa
Lava lakes have formed during historical eruptions in Mokuʻāweoweo, Mauna Loa's caldera, most recently in 1940.
Other parks
- Capulin Volcano (New Mexico): several lava lakes formed in the volcano's boca, the vent area at the base of the cinder cone that fed its lava flows, during the eruption about 54,200 years ago. Spatter built up around their edges from blobs of molten lava thrown up as gas bubbled out of the lake.
- Craters of the Moon (Idaho): several lava lakes near vents or in craters, with very little surface relief and usually ringed by levees.
More: three big changes in three years at Halemaʻumaʻu.
Sources
- National Park Service, "Lava Lakes"; rewritten in hubnx's own words. Photographs and images: U.S. Geological Survey.