Crater lake

Heaven Lake (Chonji / Tianchi), North Korea / China Landsat image of Lake Toba, the largest caldera lake in the world A crater lake that simply goes by the name Crater Lake in Oregon, USA 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

A Crater lake is a lake that forms in a volcanic crater, such as a maar, or in a caldera. Sometimes the latter are called Caldera lakes, but often this distinction is not made. Crater lakes covering active (fumarolic) volcanic vents are sometimes known as Volcanic lakes, and the water within them is often 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 can be exceptional due to the lack of inflowing streams and sediment.

Crater lakes form as incoming precipitation fills the depression. The lake deepens 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. Surface outflow can erode the deposits damming the lake, lowering its level. If the dam erodes rapidly, this can produce a breakout flood.

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 is one of the clearest lakes in the world.^[1]

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.^[2] 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 Manicouagan in Quebec, Lake Bosumtwi in Ghana and Siljan in Sweden.

List of crater lakes

Lake	Location
Blue Lake	Australia, South Australia
Lake of Albano	Italy
Lake Nemi	Italy
Lake Avernus	Italy
Lake Bolsena	Italy
Lake Vico	Italy
Lake Bracciano	Italy
Lago de Amatitlán	Guatemala
Lake Ipala	Guatemala
Lago de Atitlán	Guatemala
Laguna de Ayarza	Guatemala
Laguna de Calderas (Pacaya)	Guatemala
Laguna Chicabal	Guatemala
Lago de Coatepeque (Coatepeque Lake)	El Salvador
Laguna Verde (Apaneca, Sonsonate)	El Salvador
Laguna De Güija (Güija Lake)	El Salvador
Lago De Ilopango (Ilopango Lake)	El Salvador
Cuicocha	Ecuador
Heaven Lake (Chonji / Tianchi)	North Korea /  China
Ijen	Indonesia
Lake Toba	Indonesia
Kelut	Indonesia
Lonar crater lake	India
Lago Los Espinos	Mexico
Volcán Irazú	Costa Rica
Mount Katmai	United States, Alaska
Green Lake,[3] Kapoho Crater, Kīlauea	United States, Hawaii
Crater Lake	United States, Oregon
Medicine Lake Volcano	United States, California
Newberry Volcano	United States, Oregon
Rano Kau	Chile, Rapa Nui (Easter Island)
Rano Raraku	Chile, Rapa Nui (Easter Island)
Kerið	Iceland
Kurile Lake	Russia (Kamchatka)
Lake Manicouagan	Canada
Nazko Cone	Canada
Nemrut	Turkey
Lake Saint Ana	Romania
Lake Nyos	Cameroon
Lake Pinatubo	Philippines
Taal Lake	Philippines
Mount Ruapehu	New Zealand
Lake Taupo	New Zealand
Lake Shikotsu	Japan
Towada	Japan
Mashu	Japan
Tazawa	Japan
Soufrière	St. Vincent
Lake Wenchi [4]	Ethiopia
White Deer Lake (Baengnokdam)	South Korea

References

Notes

Further reading

• Delmelle, Pierre; Bernard, Alain (2000), "Volcanic Lakes", in Sigurdsson, Haraldur, Encyclopedia of Volcanoes, San Diego: Academic Press, 1999, pp. pp. 877–895, ISBN 012643140X 
• Varekamp, Johan C.; Rowe, Gary L. , Jr. (eds.) (2000). "Crater Lakes". Journal of Volcanology and Geothermal Research 97 (1–4): pp. 1–508. http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235962%232000%23999029998%23197405%23FLA%23&_cdi=5962&_pubType=J&view=c&_auth=y&_acct=C000029718&_version=1&_urlVersion=0&_userid=582538&md5=1911beba4cc7a30b37f932dac1925ca9.  (entire volume about crater lakes)
• Pasternack, G. B.; Varekamp, J. C. (1997). "Volcanic lake systematics I. Physical constraints". Bulletin of Volcanology 58 (7): pp. 526–538. http://www.springerlink.com/content/fe99wvduu106pwpu/?p=bd7fb6cabac34210ace7b7edcfd9f13a&pi=2. 
• Kusakabe, Minoru (ed.) (1994). "Geochemistry of Crater Lakes". Geochemical Journal 28 (3): pp. 137–306. http://www.terrapub.co.jp/journals/GJ/frame/28.html.  (entire issue about chemistry of crater lakes)

• IAVCEI Commission of Volcanic Lakes
• IAVCEI Commission of Volcanic Lakes: Some fundamentals about Crater Lakes
• The Science of Volcanic Lakes
• Volcanic Lakes of the World

See also

Wikimedia Commons has media related to: Crater lakes

• Volcanic crater
• Caldera

External links

• USGS Hawaiian Volcano Observatory: Water on volcanoes: heavy rain and crater lakes
• USGS Cascades Volcano Observatory: Volcanic Lakes
• The Science of Volcanic Lakes, Greg Pasternack, U. California Davis