A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heatedgroundwater 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 injury or death.
Definitions
There is no universally accepted definition of a hot spring. For example, one can find the phrase hot spring defined as
any geothermal spring
a spring with water temperatures above its surroundings
a natural discharge of groundwater with elevated temperatures
a type of thermal spring in which hot water is brought to the surface. The water temperature of a hot spring is usually or more above mean air temperature. Note that by this definition, "thermal spring" is not synonymous with the term "hot spring"
a spring whose hot water is brought to the surface. The water temperature of the spring is usually or more above the mean air temperature.
a spring with water above average ambient ground temperature.
a spring with water temperatures above
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. suggest that the phrase "warm spring" is not useful and should be avoided. The US NOAA Geophysical Data Center defines a "warm spring" as a spring with water between.
Flow rates
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" are tapped by 86 wells, from which 333 liters/second are pumped for 14 hours per day. This corresponds to a peak average flow rate of 3.89 liters/second per well.
The 2,850 hot springs of Beppu in Japan are the highest flow hot spring complex in Japan. Together the Beppu hot springs produce about 1,592 liters/second, or corresponding to an average hot spring flow of 0.56 liters/second.
The 303 hot springs of Kokonoe in Japan produce 1,028 liters/second, which gives the average hot spring a flow of 3.39 liters/second.
Ōita Prefecture has 4,762 hot springs, with a total flow of 4,437 liters/second, so the average hot spring flow is 0.93 liters/second.
The highest flow rate hot spring in Japan is the Tamagawa Hot Spring in Akita Prefecture, which has a flow rate of 150 liters/second. The Tamagawa Hot Spring feeds a wide stream with a temperature of.
There are at least three hot springs in the Nage region south west of Bajawa in Indonesia that collectively produce more than 453.6 liters/second.
There are another three large hot springs north east of Bajawa, Indonesia that together produce more than 450 liters/second of hot water.
The Dalhousie Springs complex in Australia had a peak total flow of more than 23,000 liters/second in 1915, giving the average spring in the complex an output of more than 325 liters/second. This has been reduced now to a peak total flow of 17,370 liters/second so the average spring has a peak output of about 250 liters/second.
In Yukon's Boreal Forest, 25 minutes north-west of Whitehorse in northern Canada, Takhini Hot Springs flows out of the Earth's interior at and 47 °C year-round.
A thermophile is an organism — a type of extremophile — that at high temperatures, between. Thermophiles are found in hot springs, as well as deep sea hydrothermal vents and decaying plant matter such as peat bogs and compost. s growing in the Map of Africa hot pool, Orakei Korako, New Zealand Some hot springs microbiota are infectious to humans:
Naegleria fowleri, an excavateamoeba, lives in warm unsalted waters worldwide and causes a fatal meningitis should the organisms enter the nose.
There are hot springs in many places 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, Turkey, and the United States, but there are hot springs in many other places as well:
Widely renowned since a chemistry professor's report in 1918 classified them as one of the world's most electrolytic mineral waters, the Rio Hondo Hot Springs in northern Argentina have become among the most visited on earth. The Cacheuta Spa is another famous hot springs in Argentina.
The springs in Europe with the highest temperatures are located in France, in a small village named Chaudes-Aigues. Located at the heart of the French volcanic region Auvergne, the thirty natural hot springs of Chaudes-Aigues have temperatures ranging from 45 °C to more than 80 °C. The hottest one, the "Source du Par", has a temperature of 82 °C. The hot waters running under the village have provided heat for the houses and for the church since the 14th Century. Chaudes-Aigues is a spa town known since the Roman Empire for the treatment of rheumatism.
Carbonate aquifers in foreland tectonic settings can host important thermal springs although located in areas commonly not characterised by regional high heat flow values. In these cases, when thermal springs are located close or along the coastlines, the subaerial and/or submarine thermal springs constitute the outflow of marine groundwater, flowing through localised fractures and karstic rock-volumes. This is the case of springs occurring along the south-easternmost portion of the Apulia region where few sulphurous and warm waters outflow in partially submerged caves located along the Adriatic coast, thus supplying the historical spas of Santa Cesarea Terme. These springs are known from ancient times and the physical-chemical features of their thermal waters resulted to be partly influenced by the sea level variations.
One of the highly potential geothermal energy reservoirs in India is the Tattapani thermal springs of Madhya Pradesh.
The silica-rich deposits found in Nili Patera, the volcanic caldera in Syrtis Major, Mars, are thought to be the remains of an extinct hot spring system.
Etiquette
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. 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.
