hot spring - Sources of heat, Flow rates, Therapeutic uses, Infections from hot springs, Hot springs parks

A spring of hot or warm groundwater which emerges at the Earth's surface and which often contains dissolved minerals and sulphurous gases. Such springs are often used as health spas. Very hot springs emerge as geysers, and may be used as sources of geothermal energy.

A hot spring is a spring whose water is hot. The groundwater emerging from hot springs is heated by geothermal processes. For example, one can find the phrase hot spring defined as

any geothermal spring a spring with water temperatures above its surroundings a natural spring with water temperature above body temperature (normally between 36.5°C and 37.5°C, that is, between 97.8°F and 99.5°F ) a natural spring with warm water above body temperature a thermal spring with water warmer than 98°F (36.7°C) a natural spring of water greater than 70°F (21.1°C) (synonymous with thermal spring) 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 6.5ºC (11.7°F) or more above mean air temperature. Note that by this definition, "thermal spring" is not synomous with the term "hot spring". a spring whose hot water is brought to the surface (synonymous with a thermal spring). a spring with water temperatures above 50°C (122°F)

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.

Sources of heat

The water issuing from a hot spring is heated by geothermal heat, i.e., heat from the Earth's interior. The water from hot springs in non-volcanic areas is heated in this manner.

Note that hot springs in volcanic areas are often at or near the boiling point.

Warm springs are sometimes the result of hot and cold springs mixing but may also occur outside of volcanic areas, such as Warm Springs, Georgia (frequented for its therapeutic effects by paraplegic U.S. President Franklin D.

Flow rates

Hot springs range in flow rate from the tiniest "seeps" to veritable rivers of hot water.

A very low flow rate hot spring fed the closed resort, Fales Hot Ditch, which is north of Bridgeport, California. There is a huge subterranean lake below Tonopah, Arizona, which provides natural hot mineral waters to several hot springs. These hot springs were used by the seven or more hot spring spas that once operated in Tonopah.

High flow hot springs

See main article on Hot spring properties.

There are many claims in the literature about the flow rates of hot springs. Some of the hot springs with high flow rates and high claimed flow rates include:

The combined flow of the 47 hot springs in Hot Springs, Arkansas is 35 liters/second. The Hay-Yo-Kay Hot Springs in Truth or Consequences, New Mexico has a flow of 99 liters/second. Lava Hot Springs in Idaho has a flow of 130 liters/second. The hot springs of Brazil's Caldas Novas ("Hot River" in Portuguese) are tapped by 86 wells, from which 333 liters/second are pumped for 14 hours per day. The 2850 hot springs of Beppu in Japan are the highest flow hot spring complex in Japan. Together the Beppu hot springs produce about 1592 liters/second, or corresponding to an average hot spring flow of 0.56 liters/second. The 303 hot springs of Kokonoe in Japan produce 1028 liters/second, which gives the average hot spring a flow of 3.39 liters/second. The Oita Prefecture has 4,762 hot springs, with a total flow of 4437 liters/second, so the average hot spring of 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. There are at least three hot springs in the Nage region 8 km southwest of Bajawa City in Indonesia that collectively produce more than 453.6 liters/second. There are another three large hot springs (Mengeruda, Wae Bana and Piga) 18km northeast of Bajawa City, Indonesia that together produce more than 450 liters/second of hot water.

Therapeutic uses

Because heated water can hold more dissolved solids, warm and especially hot springs also often have a very high mineral content, containing everything from simple calcium to lithium, and even radium.

Infections from hot springs

Unfortunately, hot springs can create ideal conditions to spread infections. There are viruses that have been collected from even very extreme environments in hot springs, like a hot spring with a temperature of 87 to 93°C and an incredibly acidic pH of 1.5 in Pozzuoli, Italy.

Hot springs parks

It is common to create parks around hot springs. Hot Springs National Park, in Hot Springs, Arkansas was the first national park in the US. There are at least seven United States national parks that feature hot springs:

Arkansas Hot Springs National Park California Death Valley National Park Lassen Volcanic National Park Idaho Yellowstone National Park Montana Yellowstone National Park Texas Big Bend National Park Washington Olympic National Park Wyoming Yellowstone National Park

Of course, there are parks in other countries that include hot springs as well, including:

Shikotsu-Toya National Park in Hokkaido, Japan Yangmingshan National Park in Taiwan Banff National Park and Jasper National Park in Canada Gorongosa National Park in Mozambique

Hot springs around the world

See main article, Hot springs around the world

There are hot springs on all continents and in many countries around the world. Countries that are renowned for their hot springs include Iceland, New Zealand, Chile and Japan, but there are interesting and unique hot springs in many other places as well:

The town of Spa, Belgium is the origin of the word "spa" and features springs with water temperatures of 32 degrees C. Iceland has many other famous hot springs, including the one feeding the Blue Lagoon spa in Grindavík, Iceland, and Europe's highest flow rate hot spring Deildartunguhver. Shiretoko National Park in Hokkaido, Japan has a hot springs waterfall called Kamuiwakkayu-no-taki Northwest Spitsbergen National Park, Spitsbergen at 80°N, contains two of earth's most northerly hot springs. The Bath hot springs are only true hot springs in the UK, by some definitions. Being located in the "Pacific Ring of Fire", Japan is in a volcanic region, and is home to many hot springs. Buddhist nuns and the "hot spring snake" both live near this set of high altitude hot springs. Champaign Hot Springs is a shallow submarine geothermal spring system along the coast of the island of Dominica, Lesser Antilles.