Lava lakes are large volumes of molten lava, usually contained in volcanic craters. These lakes can be formed from one or more vents in a crater that erupts enough lava to partially fill the crater or atop a new vent that erupts lava continuously for a period of several weeks or more and slowly builds a crater progressively higher than the surrounding ground.
Lava lake in Nyiragongo, in a molten state
Lava lake in Erta Ale, Ethiopia
Lava lake in Marum crater, Ambrym, in the archipelago of Vanuatu
Lava fountains in the Halemaʻumaʻu lava lake, Kīlauea, Hawaii
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