A volcanic crater lake is a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much lar ...

in a crater that was formed by explosive activity or a collapse during a

volcanic eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are ...

Formation

Lakes in

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber ...

s fill large craters formed by the collapse of a volcano during an eruption. Lakes in

maar A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow ...

s fill medium-sized craters where an eruption deposited debris around a vent. Crater lakes form as the created depression, within the crater rim, is filled by water. The water may come from

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hai ...

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidat ...

circulation (often hydrothermal fluids in the case of volcanic craters) or melted

ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...

. Its level rises until an equilibrium is reached between the rates of incoming and outgoing water. Sources of water loss singly or together may include evaporation, subsurface seepage, and, in places, surface leakage or overflow when the lake level reaches the lowest point on its rim. At such a saddle location, the upper portion of the lake is contained only by its adjacent natural volcanic dam; continued leakage through or surface outflow across the dam can erode its included material, thus lowering lake level until a new equilibrium of water flow, erosion, and rock resistance is established. If the volcanic dam portion erodes rapidly or fails catastrophically, the occurrence produces a breakout or outburst flood. With changes in environmental conditions over time, the occurrence of such floods is common to all natural dam types.

Examples

A well-known crater lake, which bears the same name as the geological feature, is

Crater Lake Crater Lake (Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The lake partly fills ...

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idah ...

. It is located in the caldera of

Mount Mazama Mount Mazama (''Giiwas'' in the Native American language Klamath) is a complex volcano in the state of Oregon, United States, in a segment of the Cascade Volcanic Arc and Cascade Range. Most of the mountain collapsed following a major erupti ...

. It is the deepest lake in the United States with a depth of . Crater Lake is fed solely by falling rain and snow, with no inflow or outflow at the surface, and hence is one of the clearest lakes in the world. The highest

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates ...

in the world, 6,893-m (22,615-ft)

Ojos del Salado Nevado Ojos del Salado is a dormant complex volcano in the Andes on the Argentina–Chile border. It is the highest volcano on Earth and the highest peak in Chile. The upper reaches of Ojos del Salado consist of several overlapping lava domes, l ...

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

, has a permanent crater lake about in diameter at an elevation of on its eastern side. This is most likely the highest lake of any kind in the world. Due to their unstable environments, some crater lakes exist only intermittently. Caldera lakes in contrast can be quite large and long-lasting. For instance,

Lake Toba Lake Toba ( id, Danau Toba) ( Toba Batak: ᯖᯀᯬ ᯖᯬᯅ; romanized: ''Tao Toba'') is a large natural lake in North Sumatra, Indonesia, occupying the caldera of a supervolcano. The lake is located in the middle of the northern part of the ...

(

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

) formed after its eruption around 75,000 years ago. At around by in extent and deep at its deepest point, Lake Toba is the largest crater lake in the world.

Dangers

While many crater lakes are picturesque, they can also be deadly. Gas discharges from

Lake Nyos Lake Nyos ( ) is a crater lake in the Region of Cameroon, located about northwest of Yaoundé, the capital. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity ...

in (

Cameroon Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west- central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; th ...

) suffocated 1,800 people in 1986, and crater lakes such as

Mount Ruapehu Mount Ruapehu (; ) is an active stratovolcano at the southern end of the Taupō Volcanic Zone and North Island volcanic plateau in New Zealand. It is northeast of Ohakune and southwest of the southern shore of Lake Taupō, within the Tong ...

's (New Zealand) often contribute to destructive

lahar A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extreme ...

Distinction from other volcanic lakes

Certain bodies of water, although their formation is directly related to volcanic activity, are not usually referred to as crater lakes, including: *Lakes created by volcanic dams due to lava flowing outside of the volcanic edifice/

(such as

Garibaldi Lake Garibaldi Lake is a turquoise-coloured alpine lake in British Columbia, Canada, located 37 km (23 mi) north of Squamish and 19 km (12 mi) south of Whistler. The lake lies within Garibaldi Provincial Park, which features moun ...

in Canada, Fuji Five Lakes in Japan) *Closed

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can ...

lagoons (such as Clipperton lagoon), whose formation process also implies subsequent biogeomorphologic processes *Ponds encountered at the bottom of waterfalls occurring in volcanic canyons in a volcanic context, but not within a volcanic edifice/caldera (such as Trou de Fer on

Réunion Island Réunion (; french: La Réunion, ; previously ''Île Bourbon''; rcf, label= Reunionese Creole, La Rényon) is an island in the Indian Ocean that is an overseas department and region of France. It is located approximately east of the island o ...

)

List

Africa

File:Jezioro Słoniowe (Barombi Mbu) - okolice Kumba - 001304s.jpg, Lake Barombi, Cameroon File:Lac de cratère de Mballang près de Ngaoundéré1.jpg, Lake Mbalang, Cameroon File:Lake Awing 2.jpg, Lake Awing, Cameroon File:Lake Mfou on Mt Mbapit.jpg, Mount Mbapit crater lake, Cameroon File:Lac Tyson.jpg, Lake Tison, Cameroon File:The Amazing Lake Bambili.jpg, Lake Bambili, North West Cameroon File:Monoun.jpg, Lake Monoun exploded in 1984, Cameroon File:Manengouba- lac jumeaux.jpg, Lake Manengouba, Cameroon File:Dendi Caldera.jpg, Mount Dendi double crater lake, Ethiopia (seen from the ISS) File:Wonchi Lake of Ethiopia.jpg, Wonchi crater lake, Ethiopia File:Lac dziani vue.jpg, Dziani Dzaha, Mayotte

Antarctica and the sub-Antarctic islands

Asia

File:Fahey DSCF1827 (6074447178).jpg,

Heaven Lake Heaven Lake ( Korean: , ''Ch'ŏnji'' or ''Cheonji''; zh, 天池, ''Tiānchí''; Manchu: ''Tamun omo'' or ''Tamun juce'') is a crater lake on the border between China and North Korea. It lies within a caldera atop the volcanic Paektu Moun ...

, the crater lake of

Paektu Mountain Paektu Mountain (), also known as Baekdu Mountain and in China as Changbai Mountain ( zh, s=长白山, t=長白山; Manchu: Golmin Šanggiyan Alin), is an active stratovolcano on the Chinese–North Korean border. At , it is the highest m ...

on the

China–North Korea border The China–North Korea border is the international border separating the People's Republic of China (PRC) and the Democratic People's Republic of Korea (DPRK). It runs for 1,352 km (840 mi) from the estuary of the Yalu River in the ...

File:Mount Aso acid lake seen from helicopter by ET.jpg,

Mount Aso Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, ...

crater lake, Japan File:Taal volcano aerial.jpg, Taal volcano, Philippines File:Mount Pinatubo 20081229 01.jpg, Lake Pinatubo, Philippines, formed after the 1991 eruption of

Mount Pinatubo Mount Pinatubo is an active stratovolcano in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon. Its eruptive histo ...

Europe

File:Iceland2009-BradWeber-Kerid.jpg, Kerið crater lake, Iceland

North America

File:Crater lake oregon.jpg, Crater Lake in Oregon, US File:Katmai Crater 1980.jpg, Katmai crater lake, Alaska, US File:Kluft-photo-SodaLake-pano-2018-11.jpg, Soda Lakes maar volcano in Nevada, US File:Irazu crater lake from the mirador by ET.jpg, Irazú crater lake, Costa Rica File:Laguna de Maderas by ET.jpg, Maderas crater lake ( Ometepe Island), Nicaragua File:Ilopango caldera.jpg, Lake Ilopango,

El Salvador El Salvador (; , meaning " The Saviour"), officially the Republic of El Salvador ( es, República de El Salvador), is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south by ...

, crater lake File:Coatepeque Vista.jpg,

Coatepeque Caldera Caldera De Coatepeque (Nahuatl ''cōātepēc'', "at the snake hill") is a volcanic caldera in El Salvador in Central America. The caldera was formed during a series of rhyolitic explosive eruptions between about 72,000 and 57,000 years ago. ...

, crater lake

Oceania

File:Satellite view of Niuafo'ou, 2005-03-19.jpg, Niuafo'ou crater lake, Tonga

South America

File:Laguna de Cuicocha 01.jpg, Cuicocha, Ecuador

References

{{Earth's landforms