Hot spring

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Grand Prismatic Spring and Midway Geyser Basin in Yellowstone National Park Aerial view of Grand Prismatic (23428929375).jpg
Grand Prismatic Spring and Midway Geyser Basin in Yellowstone National Park

A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater that rises from the Earth's crust. While some of these springs contain water that is a safe temperature for bathing, others are so hot that immersion can result in an injury or death.



"Blood Pond" hot spring in Beppu, Japan Natural iron hot spring.jpg
"Blood Pond" hot spring in Beppu, Japan

There is no universally accepted definition of a hot spring. For example, one can find the phrase hot spring defined as

Hammam Maskhoutine in Algeria GM Guelma Hammam Challala01.jpg
Hammam Maskhoutine in Algeria
Hot spring in Lassen Volcanic National Park HotSpring 8344.jpg
Hot spring in Lassen Volcanic National Park

The related term "warm spring" is defined as a spring with water temperature less than a hot spring by many sources, although Pentecost et al. (2003) suggest that the phrase "warm spring" is not useful and should be avoided. [5] The US NOAA Geophysical Data Center defines a "warm spring" as a spring with water between 20 and 50 °C (68 and 122 °F).

Sources of heat

Much of the heat is created by decay of naturally radioactive elements. An estimated 45 to 90 percent of the heat escaping from the Earth originates from radioactive decay of elements mainly located in the mantle. [17] [18] [19] The major heat-producing isotopes in the Earth are potassium-40, uranium-238, uranium-235, and thorium-232. [20]

The radiogenic heat from the decay of U and Th are now the major contributors to the earth's internal heat budget. Evolution of Earth's radiogenic heat.svg
The radiogenic heat from the decay of U and Th are now the major contributors to the earth's internal heat budget.

Water issuing from a hot spring is heated geothermally, that is, with heat produced from the Earth's mantle. In general, the temperature of rocks within the earth increases with depth. The rate of temperature increase with depth is known as the geothermal gradient. If water percolates deeply enough into the crust, it will be heated as it comes into contact with hot rocks. The water from hot springs in non-volcanic areas is heated in this manner.

Steam Crepuscular rays at Mammoth Hot Springs Crepuscular rays and Dead trees at Mammoth Hot Springs.jpg
Steam Crepuscular rays at Mammoth Hot Springs

In active volcanic zones such as Yellowstone National Park, water may be heated by coming into contact with magma (molten rock). The high temperature gradient near magma may cause water to be heated enough that it boils or becomes superheated. If the water becomes so hot that it builds steam pressure and erupts in a jet above the surface of the Earth, it is called a geyser. If the water only reaches the surface in the form of steam, it is called a fumarole. If the water is mixed with mud and clay, it is called a mud pot.

Note that hot springs in volcanic areas are often at or near the boiling point. People have been seriously scalded and even killed by accidentally or intentionally entering these springs.

Warm springs are sometimes the result of hot and cold springs mixing. They may occur within a volcanic area or outside of one. One example of a non-volcanic warm spring is Warm Springs, Georgia (frequented for its therapeutic effects by paraplegic U.S. President Franklin D. Roosevelt, who built the Little White House there).

Flow rates

Deildartunguhver, Iceland: the highest flow hot spring in Europe Islande source Deildartunguhver.jpg
Deildartunguhver, Iceland: the highest flow hot spring in Europe

Hot springs range in flow rate from the tiniest "seeps" to veritable rivers of hot water. Sometimes there is enough pressure that the water shoots upward in a geyser, or fountain.

High-flow hot springs

There are many claims in the literature about the flow rates of hot springs. There are many more high flow non-thermal springs than geothermal springs. For example, there are 33 recognized "magnitude one springs" (having a flow in excess of 2,800 L/s (99 cu ft/s) in Florida alone. Silver Springs, Florida has a flow of more than 21,000 L/s (740 cu ft/s). Springs with high flow rates include:

Therapeutic uses

Japanese open air hot spring (onsen) in Nanki-Katsuura Onsen Onsen in Nachikatsuura, Japan.jpg
Japanese open air hot spring (onsen) in Nanki-Katsuura Onsen
Hammam Essalihine, Roman hot spring in Algeria Bain romain de Khenchela.jpg
Hammam Essalihine, Roman hot spring in Algeria

Because heated water can hold more dissolved solids than cold water, warm and especially hot springs, including beneficial sulphurous water, [25] often with very high mineral content, containing everything from simple calcium to lithium, and even radium. Because of both the folklore and the claimed medical value some of these springs have, they are often popular tourist destinations, and locations for rehabilitation clinics for those with disabilities. [26] [27] [28]


A thermophile is an organism — a type of extremophile — that thrives at high temperatures, between 45 and 80 °C (113 and 176 °F). [29] Thermophiles are found in hot springs, as well as deep sea hydrothermal vents and decaying plant matter such as peat bogs and compost.

Algal mats growing in the Map of Africa hot pool, Orakei Korako, New Zealand Algal mats on hot pool, Orakei Korako 1.jpg
Algal mats growing in the Map of Africa hot pool, Orakei Korako, New Zealand

Some hot springs microbiota are infectious to humans:


Distribution of geothermal springs in the US Geothermal springs map US.png
Distribution of geothermal springs in the US
Macaques enjoying an open air hot spring or "onsen" in Nagano Jigokudani hotspring in Nagano Japan 001.jpg
Macaques enjoying an open air hot spring or "onsen" in Nagano

There are hot springs in many countries and on all continents of the world. Countries that are renowned for their hot springs include China, Costa Rica, Iceland, Iran, Japan, New Zealand, Peru, Taiwan, Turkey, and the United States, but there are hot springs in many other places as well:

Chaudes-Aigues-Lavoir Chaudes-Aigues-Lavoir.JPG


The customs and practices observed differ depending on the hot spring. It is common practice that bathers should wash before entering the water so as not to contaminate the water (with/without soap). [41] In many countries, like Japan, it is required to enter the hot spring with no clothes on, including swimwear. Typically in these circumstances, there are different facilities or times for men and women. In some countries, if it is a public hot spring, swimwear is required.

See also

Related Research Articles

Geyser Hot spring characterized by intermittent discharge of water ejected turbulently and accompanied by steam

A geyser is a spring characterized by intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in a few places on Earth. Generally all geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Generally, surface water works its way down to an average depth of around 2,000 metres (6,600 ft) where it contacts hot rocks. The resultant boiling of the pressurized water results in the geyser effect of hot water and steam spraying out of the geyser's surface vent.

Long Valley Caldera Depression in California, United States

Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about 20 miles (32 km) long (east-west), 11 miles (18 km) wide (north-south), and up to 3,000 feet (910 m) deep.

Geothermal energy Thermal energy generated and stored in the Earth

Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. The geothermal energy of the Earth's crust originates from the original formation of the planet and from radioactive decay of materials. The geothermal gradient, which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of heat from the core to the surface. The adjective geothermal originates from the Greek roots γη (geo), meaning earth, and θερμος (thermos), meaning hot.

Geothermal areas of Yellowstone geyser basins and other geothermal features in Yellowstone National Park

The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10,000. A study that was completed in 2011 found that a total of 1,283 geysers have erupted in Yellowstone, 465 of which are active during an average year. These are distributed among nine geyser basins, with a few geysers found in smaller thermal areas throughout the Park. The number of geysers in each geyser basin are as follows: Upper Geyser Basin (410), Midway Geyser Basin (59), Lower Geyser Basin (283), Norris Geyser Basin (193), West Thumb Geyser Basin (84), Gibbon Geyser Basin (24), Lone Star Geyser Basin (21), Shoshone Geyser Basin (107), Heart Lake Geyser Basin (69), other areas (33). Although famous large geysers like Old Faithful are part of the total, most of Yellowstone's geysers are small, erupting to only a foot or two. The hydrothermal system that supplies the geysers with hot water sits within an ancient active caldera. Many of the thermal features in Yellowstone build up sinter, geyserite, or travertine deposits around and within them.

Hydrothermal circulation in its most general sense is the circulation of hot water. Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earth's crust. In general, this occurs near volcanic activity, but can occur in the deep crust related to the intrusion of granite, or as the result of orogeny or metamorphism.

Geothermal areas in Lassen Volcanic National Park

The geothermal areas in Lassen Volcanic National Park include several groups of hot springs and fumaroles, as remnants of former volcanic activity, exist in Lassen Volcanic National Park. Most of these lie in or are closely adjacent to Mount Tehama's caldera. Bumpass Hell is the most spectacular of these, but others of importance are Sulphur Works, Little Hot Springs Valley, Boiling Springs Lake and Devil's Kitchen. In each thermal area, the highest temperature of water generally is close to the boiling temperature at the altitude of the particular spring or fumarole — 198 °F (92 °C) at Bumpass Hell and 191 °F (88 °C) on the northwest flanks of Lassen Peak. Temperatures as high as 230 °F (110 °C) have been recorded in the park.

El Tatio mountain

El Tatio is a geyser field located in the Andes Mountains of northern Chile at 4,320 metres (14,170 ft) above mean sea level. Various etymologies have been proposed for the name "El Tatio", which might mean "oven" or "grandfather". It is the third-largest geyser field in the world and the largest in the Southern Hemisphere.

Water heating Thermodynamic process that uses energy sources to heat water

Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated to steam have many uses.

Geothermal heating methods of heating and cooling a building using underground heat

Geothermal heating is the direct use of geothermal energy for some heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004. As of 2007, 28 GW of geothermal heating capacity is installed around the world, satisfying 0.07% of global primary energy consumption. Thermal efficiency is high since no energy conversion is needed, but capacity factors tend to be low since the heat is mostly needed in the winter.

Steamboat Springs (Nevada) mountain in United States of America

Steamboat Springs is a small volcanic field of rhyolitic lava domes and flows in western Nevada, located south of Reno. There is extensive geothermal activity in the area, including numerous hot springs, steam vents, and fumaroles. The residential portions of this area, located mostly east of Steamboat Creek and south of modern-day SR 341, are now known simply as Steamboat.

Chaudes-Aigues Commune in Auvergne-Rhône-Alpes, France

Chaudes-Aigues is a commune in the Cantal department in south-central France. It is a spa town, famous for its hot spring waters.

Electric heating process in which electrical energy is converted to heat

Electric heating is a process in which electrical energy is converted to heat energy. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an electrical device that converts an electric current into heat. The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy. Most modern electric heating devices use nichrome wire as the active element; the heating element, depicted on the right, uses nichrome wire supported by ceramic insulators.

Geothermal power electricity generated from geothermal energy

Geothermal power is power generated by geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries, while geothermal heating is in use in 70 countries.

Hot Creek (Mono County) river in the United States of America

Hot Creek, starting as Mammoth Creek, is a stream in Mono County of eastern California, in the Western United States. It is within the Inyo National Forest.

Waimangu Volcanic Rift Valley Volcanic Valley in New Zealand

The Waimangu Volcanic Rift Valley is the hydrothermal system created on 10 June 1886 by the volcanic eruption of Mount Tarawera, on the North Island of New Zealand. It encompasses Lake Rotomahana, the site of the Pink and White Terraces, as well as the location of the Waimangu Geyser, which was active from 1900 to 1904. The area has been increasingly accessible as a tourist attraction and contains Frying Pan Lake, which is the largest hot spring in the world, and the steaming and usually pale blue Inferno Crater Lake, the largest geyser-like feature in the world although the geyser itself cannot be seen since it plays at the bottom of the lake.

The Glossary of Geothermal Heating and Cooling provides definitions of many terms used within the Geothermal heat pump industry. The terms in this glossary may be used by industry professionals, for education materials, and by the general public.

Yangbajain Geothermal Field

The Yangbajain Geothermal Field (羊八井地热田) is a geothermal field near the town of Yangbajain in Damxung County, Tibet Autonomous Region, China. The fluid is heated by magmatic activity not far below the surface. It is a tourist attraction and also supplies steam to a major power plant with 25,000 kW capacity. Concerns have been raised that untreated waste water is polluting the river downstream from the power plant,

Hot dry rock (HDR) is an abundant source of geothermal energy available for use. A vast store of thermal energy is contained within hot – but essentially dry – impervious crystalline basement rocks found almost everywhere deep beneath the Earth's surface. A concept for the extraction of useful amounts of geothermal energy from HDR originated at the Los Alamos National Laboratory in 1970, and Laboratory researchers were awarded a U.S. patent covering it.


Puchuldiza is a geothermal field in the Tarapacá Region of Chile. It is part of the Central Volcanic Zone of the Andes, close to the active volcano Isluga and several older volcanoes in the neighbourhood; the most recent activity from one of the neighbouring volcanoes was 900,000 ± 300,000 years ago. Geothermal features include geysers and hot springs. Puchuldiza has been inspected for the possibility that it may be suitable as a source for geothermal energy.


  1. "MSN Encarta definition of hot spring". Archived from the original on 2009-01-22.
  2. Miriam-Webster Online dictionary definition of hot spring
  3. Wordsmyth definition of hot spring
  4. American Heritage dictionary, fourth edition (2000) definition of hot spring Archived 2007-03-10 at the Wayback Machine
  5. 1 2 Allan Pentecost; B. Jones; R.W. Renaut (2003). "What is a hot spring?". Can. J. Earth Sci. 40 (11): 1443–6. Bibcode:2003CaJES..40.1443P. doi:10.1139/e03-083. Archived from the original on 2007-03-11. provides a critical discussion of the definition of a hot spring.
  6. Infoplease definition of hot spring
  7. Random House Unabridged Dictionary, © Random House, Inc. 2006. definition of hot spring
  8. Wordnet 2.0 definition of hot spring
  9. Ultralingua Online Dictionary definition of hot spring
  10. Rhymezone definition of hot spring
  11. Lookwayup definition of hot spring
  12. Columbia Encyclopedia, sixth edition, article on hot spring Archived 2007-02-11 at the Wayback Machine
  13. Don L. Leet (1982). Physical Geology (6th ed.). Englewood Cliffs, NJ: Prentice-Hall. ISBN   978-0-13-669706-0. A thermal spring is defined as a spring that brings warm or hot water to the surface. Leet states that there are two types of thermal springs; hot springs and warm springs.
  14. "Water Words Glossary - Hot Spring". NALMS. 2007. Archived from the original on January 14, 2008. Retrieved 2008-04-04.
  15. For example, ambient ground temperature is usually around 55–57 °F (13–14 °C) in the eastern United States
  16. US NOAA Geophysical Data Center definition
  17. Turcotte, DL; Schubert, G (2002). "4". Geodynamics (2nd ed.). Cambridge, England, UK: Cambridge University Press. pp. 136–7. ISBN   978-0-521-66624-4.
  18. Anuta, Joe (2006-03-30). "Probing Question: What heats the earth's core?". Retrieved 2007-09-19.
  19. Johnston, Hamish (19 July 2011). "Radioactive decay accounts for half of Earth's heat". Institute of Physics. Retrieved 18 June 2013.
  20. Sanders, Robert (2003-12-10). "Radioactive potassium may be major heat source in Earth's core". UC Berkeley News. Retrieved 2007-02-28.
  21. Terme di Saturnia Archived 2013-04-17 at the Wayback Machine , website
  22. John W. Lund; James C. Witcher (December 2002). "Truth or Consequences, New Mexico- A Spa City" (PDF). GHC Bulletin. 23 (4).
  23. W. F. Ponder (2002). "Desert Springs of Great Australian Arterial Basin". Conference Proceedings. Spring-fed Wetlands: Important Scientific and Cultural Resources of the Intermountain Region. Archived from the original on 2008-10-06. Retrieved 2013-04-06.
  24. "Archived copy". Archived from the original on 2014-02-26. Retrieved 2013-09-28.CS1 maint: archived copy as title (link)
  25. Zuffianò, L. E.; Polemio, M.; Laviano, R.; De Giorgio, G.; Pallara, M.; Limoni, P. P.; Santaloia, F. (2018-07-06). "Sulphuric acid geofluid contribution on thermal carbonate coastal springs (Italy)". Environmental Earth Sciences. 77 (13): 517. doi:10.1007/s12665-018-7688-8. ISSN   1866-6299.
  26. The web site of the Roosevelt rehabilitation clinic in Warm Springs, Georgia Archived 2003-09-19 at the Wayback Machine
  27. "Web site of rehabilitation clinics in Central Texas created because of a geothermal spring". Archived from the original on 2018-06-01. Retrieved 2020-01-17.
  28. "Archived copy". Archived from the original on 2014-02-26. Retrieved 2013-09-28.CS1 maint: archived copy as title (link) Analytical results for Takhini Hot Springs geothermal water:
  29. Madigan MT, Martino JM (2006). Brock Biology of Microorganisms (11th ed.). Pearson. p. 136. ISBN   978-0-13-196893-6.
  30. Naegleria at eMedicine
  31. Shinji Izumiyama; Kenji Yagita; Reiko Furushima-Shimogawara; Tokiko Asakura; Tatsuya Karasudani; Takuro Endo (July 2003). "Occurrence and Distribution of Naegleria Species in Thermal Waters in Japan". J Eukaryot Microbiol. 50: 514–5. doi:10.1111/j.1550-7408.2003.tb00614.x. PMID   14736147.
  32. Yasuo Sugita; Teruhiko Fujii; Itsurou Hayashi; Takachika Aoki; Toshirou Yokoyama; Minoru Morimatsu; Toshihide Fukuma; Yoshiaki Takamiya (May 1999). "Primary amebic meningoencephalitis due to Naegleria fowleri: An autopsy case in Japan". Pathology International. 49 (5): 468–70. doi:10.1046/j.1440-1827.1999.00893.x. PMID   10417693.
  33. CDC description of acanthamoeba
  34. Miyamoto H, Jitsurong S, Shiota R, Maruta K, Yoshida S, Yabuuchi E (1997). "Molecular determination of infection source of a sporadic Legionella pneumonia case associated with a hot spring bath". Microbiol. Immunol. 41 (3): 197–202. doi:10.1111/j.1348-0421.1997.tb01190.x. PMID   9130230.
  35. Eiko Yabauuchi; Kunio Agata (2004). "An outbreak of legionellosis in a new facility of hot spring Bath in Hiuga City". Kansenshogaku Zasshi. 78 (2): 90–8. doi:10.11150/kansenshogakuzasshi1970.78.90. ISSN   0387-5911. PMID   15103899.
  36. Welcome Argentina: Turismo en Argentina 2009
  37. Santaloia, F.; Zuffianò, L. E.; Palladino, G.; Limoni, P. P.; Liotta, D.; Minissale, A.; Brogi, A.; Polemio, M. (2016-11-01). "Coastal thermal springs in a foreland setting: The Santa Cesarea Terme system (Italy)". Geothermics. 64: 344–361. doi:10.1016/j.geothermics.2016.06.013. ISSN   0375-6505.
  38. Ravi Shanker; J.L. Thussu; J.M. Prasad (1987). "Geothermal studies at Tattapani hot spring area, Sarguja district, central India". Geothermics. 16 (1): 61–76. doi:10.1016/0375-6505(87)90079-4.
  39. D. Chandrasekharam; M.C. Antu (August 1995). "Geochemistry of Tattapani thermal springs, Himachal Pradesh, India—field and experimental investigations". Geothermics. 24 (4): 553–9. doi:10.1016/0375-6505(95)00005-B.
  40. Skok, J. R.; Mustard, J. F.; Ehlmann, B. L.; Milliken, R. E.; Murchie, S. L. (December 2010). "Silica deposits in the Nili Patera caldera on the Syrtis Major volcanic complex on Mars". Nature Geoscience. 3 (12): 838–841. doi:10.1038/ngeo990. ISSN   1752-0894.
  41. Fahr-Becker, Gabriele (2001). Ryokan. p. 24. ISBN   978-3-8290-4829-3.

Further reading