Crater lake

A crater lake that simply goes by the name "Crater Lake", in Oregon, USA

Heaven Lake (Chonji / Tianchi), North Korea / China

Cuicocha, Ecuador

Lake formed after 1991 eruption of Mount Pinatubo, Philippines

Mount Katmai, Alaska, USA

Mount Wenchi crater lake, Ethiopia

Nemrut, Turkey

Volcán Irazú, Costa Rica

This page describes the geological feature. For the lake of the same name in Oregon, see Crater Lake.

A crater lake is a lake that forms in a volcanic crater, caldera, or maar. Incoming precipitation fills the depression to form a deepening lake, until an equilibrium is reached between the rate of water coming in and the rate of water loss due to evaporation, subsurface drainage, and possibly also surface outflow if the lake fills the crater up to the lowest point on its rim. Crater lakes covering active (fumarolic) volcanic vents are often known as volcanic lakes, and the water within them is typically acidic, saturated with volcanic gases, and cloudy with a strong greenish color. Lakes located in dormant or extinct volcanoes tend to have fresh water, and the water clarity in such lakes is often exceptional due to the lack of inflowing streams and sediment.

A well-known crater lake, which bears the same name as the geological feature, is Crater Lake in Oregon, USA. It is located in the caldera of Mount Mazama, hence the name "Crater Lake" is somewhat of a misnomer. It is the deepest lake in the United States with a depth of 594 m (1,949 ft). Crater Lake is fed solely by falling rain and snow, with no inflow or outflow at the surface, and hence has the clearest water of any lake in the world.

The highest volcano in the world, 6,893 metres (22,615 ft) Ojos del Salado, has a permanent crater lake about 100 metres (300 ft) in diameter at an elevation of 6,390 m (20,960 ft) on its eastern side.^[1] This is most likely the highest lake of any kind in the world.

Due to their unstable environment, some crater lakes exist only intermittently. Caldera lakes in contrast can be quite large and long-lasting; for instance, Lake Toba formed after its eruption around 70,000 years ago and has an area of over 1,000 square kilometres.

While many crater lakes are picturesque, they can also be deadly. Gas discharges from Lake Nyos suffocated 1,800 people in 1986, and crater lakes such as Mount Ruapehu's often contribute to destructive lahars.

Lakes can also fill impact craters, but these are not usually referred to as crater lakes except in a few isolated cases. Example of such impact crater lakes include Lake Bosumtwi in Ghana and Siljan in Sweden.

In addition, it has also come to be believed by some native peoples that Crater Lake may in fact be the site of the Lake of Fire foretold by the Bible in the book of Revelation.

1 Notable crater lakes
2 See also
3 References
4 External links

Notable crater lakes

Lake	Location
Lake of Albano	Italy
Lago de Atitlán	Guatemala
Blue Lake	Australia, South Australia
Lake Bolsena	Italy
Lake Bracciano	Italy
Laguna Chicabal	Guatemala
Lago de Coatepeque	El Salvador
Crater Lake	United States, Oregon
Cuicocha	Ecuador
Heaven Lake (Chonji / Tianchi)	North Korea / China
Volcán Irazú	Costa Rica
Kapoho Crater	United States, Hawaii
Mount Katmai	United States, Alaska
Rano Kau	Chile, Rapa Nui (Easter Island)
Kelut	Indonesia
Kerið	Iceland
Kurile Lake	Russia (Kamchatka)
Medicine Lake Volcano	United States, California
Lake Manicouagan	Canada
Mashu	Japan
Lake Nemi	Italy
Nemrut	Turkey
Newberry Volcano	United States, Oregon
Lake Nyos	Cameroon
Mount Pinatubo	Philippines
Rano Raraku	Chile, Rapa Nui (Easter Island)
Mount Ruapehu	New Zealand
Lake Shikotsu	Japan
Soufrière	St. Vincent
Taal Lake	Philippines
Lake Taupo	New Zealand
Tazawa
Lake Toba	Indonesia
Towada	Japan
Lake Vico	Italy
Nazko Cone	Canada
Lake Wenchi ^[2]	Ethiopia