Aerial view of a lava lake in Pu'u '?'? crater, east rift zone of K?lauea. The crater is about 820 ft (250 m) in diameter.
Aerial view of a lava lake atop the K?pa?ianah? vent on the east rift zone of K?lauea volcano. Since the collapse of the Halema?uma?u and Pu'u O'o craters in 2018, K?lauea currently has no active lava lakes.
Lava lakes are large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression. The term is used to describe both lava lakes that are wholly or partly molten and those that are solidified (sometimes referred to as frozen lava lakes in this case).
from one or more vents in a crater that erupts enough lava to partially fill the crater; or
when lava pours into a crater or broad depression and partially fills 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 lakes occur in a variety of volcanic systems, ranging from the basaltic Erta Ale lake in Ethiopia and the basaltic andesite volcano of Villarrica, Chile, to the unique phonolitic lava lake at Mt. Erebus, Antarctica. Lava lakes have been observed to exhibit a range of behaviours. A "constantly circulating, apparently steady-state" lava lake was observed during the 1969-1971 Mauna Ulu eruption of Kilauea, Hawaii. By contrast, a lava lake at the 1983-1984 Pu?u ? eruption of Kilauea displayed cyclic behaviour with a period of 5-20 minutes; gas "pierced the surface" of the lake, and the lava rapidly drained back down the conduit before the onset of a new phase of lake activity.
The behaviour observed is influenced by the combined effects of pressure within the reservoir, exsolution and decompression of gas bubbles within the conduit and, potentially, exsolution of bubbles within the magma reservoir. Superimposed upon this is the effect of bubbles rising through the liquid, and coalescence of bubbles within the conduit. The interactions of these effects can create either a steady-state recirculating lake, or a lake level that periodically rises and then falls.
Persistent lava lakes are a rare phenomenon. Only a few volcanoes have hosted persistent or near-persistent lava lakes during recent decades:
Nyiragongo's lava lake has usually been the largest and most voluminous in recent history, reaching 700 meters wide in 1982, although Masaya is believed to have hosted an even larger lava lake at the time of the Spanish conquest, being 1,000 meters wide in 1670. The lava lake at Masaya came back in January 2016.
In addition to the aforementioned persistent lava lakes, a certain number of occurrences of temporary lava lakes (sometimes called lava ponds or lava pools, depending on their size and nature) have also been observed and are listed in the following table.
List of volcanoes having displayed past or present lava lake activity
Persistent or near-persistent lava lakes during recent decades
Ambrym (two lava lakes in both Benbow and Marum craters since around 1991; following an earthquake in December 2018 both lakes are buried under collapsed craters and as of July 2019 lava is only partially visible)
Nyamuragira (lava lake located within the summit caldera, confirmed for the first time in 1921, drained in 1938, and temporary lava pond in the Kituro cone on the SW flank, during the 1948 eruption)
^Swanson et al. (1979) "Ground deformation at Pu'u 'O'o. U.S. Geological Survey Chronological narrative of the 1969-71 Mauna Ulu eruption of Kilauea volcano". US Geological Survey Professional Paper 1056
^Wolfe et al. (1988). "Geologic observations and chronology of eruptive events". US Geological Survey Professional Paper 1463
^Witham and Llewellin (2006). "Stability of Lava Lakes". '+Journal of Volcanology and Geothermal Research vol. 158 p.321-332