# Lava lake

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).

## Formation

Lava lakes can form in three ways:
* 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.

### Behaviors

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 Kīlauea, Hawaiʻi. By contrast, a lava lake at the 1983–1984 Puʻu ʻŌʻō 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.

## Notable examples

Persistent lava lakes are a rare phenomenon. Only a few volcanoes have hosted persistent or near-persistent lava lakes during recent decades:
* Mount Erebus, Ross Island, Antarctica
* Erta Ale, Ethiopia
* Kīlauea, Big Island, Hawaiʻi
* Masaya volcano, Nicaragua
* Mount Michael, Saunders Island, South Sandwich Islands
* Mount Nyiragongo, Democratic Republic of the Congo
* Mount Yasur, Vanuatu
The lava lakes at Ambrym volcano disappeared after a large eruption in December 2018.
For many years, Kīlauea had two persistent lava lakes: one in the Halemaʻumaʻu vent cavity within the summit caldera, and another within the Puʻu ʻŌʻō cone located on the east rift zone of the volcano. In May 2018, both of these lava lakes disappeared as a result of increased activity in Kīlauea's east rift zone. The lava lake at Halemaʻumaʻu returned in December 2020, after Kīlauea's first eruption in over two years. The lava lake solidified after the eruption ended in May 2021, but returned again when eruptive activity at Halemaʻumaʻu resumed on September 29, 2021. Following the 2021 eruption, three more occurred on January 5, 2023; June 7, 2023; and September 10, 2023. As of January 2024, Halemaʻumaʻu is not erupting and the lava lake is no longer active.
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

| Volcano | Location |
| Persistent or near-persistent lava lakes during recent decades ||
| Erta Ale | Ethiopia |
| Mount Erebus | Ross Island, Antarctica |
| Kīlauea Halemaʻumaʻu | Hawaiʻi (Big Island) |
| Nyiragongo (the largest one in the past century) | Democratic Republic of the Congo |
| Mount Michael | Saunders Island, South Sandwich Islands |
| 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) | Ambrym Island, Vanuatu |
| Recent intermittent lava lake activity ||
| Masaya | Nicaragua |
| Mount Yasur | Tanna Island, Vanuatu |
| Villarrica | Chile |
| Karthala | Grande Comore, Comoros |
| Piton de la Fournaise (small temporary lava pond in Dolomieu crater) | Réunion Island |
| Ol Doinyo Lengai (only active volcano in the world emitting carbonatite lava) | Tanzania |
| Turrialba (small lake) | Costa Rica |
| Unconfirmed lava lake activity ||
| Telica (possibly in 1971 and 1999–2000) | Nicaragua |
| Tungurahua (possibly in 1999) | Ecuador |
| Tofua (possibly in 2004 and 2006) | Tofua Island, Tonga |
| Nabro (possibly in 2012) | Eritrea |
| Lava lake activity suggested by satellite remote-sensing data ||
| Mount Michael | Saunders Island, South Sandwich Islands |
| Mount Belinda | Montagu Island, South Sandwich Islands |
| Mawson Peak | Heard Island |
| Past lava lake activity ||
| Kīlauea Puʻu ʻŌʻō crater (1983-2018, collapsed during the 2018 Puna eruption) | Hawaiʻi (Big Island) |
| Mount Matavanu (during the 1905–1911 eruption) | Savai'i Island, Samoa |
| 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) | Democratic Republic of the Congo |
| Capelinhos (in 1958, a Surtseyan eruption) | Faial Island, Azores |
| Surtsey (in 1964, during the 1963–1967 eruption which led to the formation of the island) | Iceland |
| Tolbachik, part of the Klyuchevskaya volcanic complex (last observation of lava lake activity in 1964) | Kamchatka, Russia |
| Etna (in 1974) | Sicily, Italy |
| Ardoukôba (in 1978) | Djibouti |
| Mount Mihara (in 1986) | Izu Ōshima, Japan |
| Stromboli (in 1986 and 1989) | Aeolian Islands, Italy |
| La Cumbre (in 1995) | Fernandina Island, Galápagos |
| Pacaya (in 2000 and 2001) | Guatemala |
| Mount Edziza (0.9 million years ago) | British Columbia, Canada |
| Lava lake activity on other planetary bodies ||
| Loki Patera | Io |
| Janus Patera | Io |
| Pele | Io |