Misplaced Pages

#872127

55-585: In Japan, onsen ( 温泉 ) are hot springs and the bathing facilities and traditional inns around them. There are approximately 25,000 hot spring sources throughout Japan, and approximately 3,000 onsen establishments use naturally hot water from these geothermally heated springs. Onsen may be either outdoor baths ( 露天風呂 or 野天風呂 , roten-buro / noten-buro ) or indoor baths ( 内湯 , uchiyu ) . Traditionally, onsen were located outdoors, although many inns have now built indoor bathing facilities as well. Nowadays, as most households have their baths,

110-638: A pH as low as 0.8, to alkaline chloride springs saturated with silica , to bicarbonate springs saturated with carbon dioxide and carbonate minerals . Some springs also contain abundant dissolved iron. The minerals brought to the surface in hot springs often feed communities of extremophiles , microorganisms adapted to extreme conditions, and it is possible that life on Earth had its origin in hot springs. Humans have made use of hot springs for bathing, relaxation, or medical therapy for thousands of years. However, some are hot enough that immersion can be harmful, leading to scalding and, potentially, death. There

165-455: A sentō at an onsen , all guests are expected to wash and rinse themselves thoroughly before entering the hot water. Bathing stations are equipped with stools, faucets, wooden buckets, and toiletries such as soap and shampoo; nearly all onsen also provide removable shower heads for bathing convenience. Entering the onsen while still dirty or with traces of soap on the body is socially unacceptable. Guests are not allowed to wear swimsuits in

220-438: A 3.48 billion year old geyserite that seemingly preserved fossilized microbial life, stromatolites, and biosignatures. Researchers propose pyrophosphite to have been used by early cellular life for energy storage and it might have been a precursor to pyrophosphate. Phosphites, which are present at hot springs, would have bonded together into pyrophosphite within hot springs through wet-dry cycling. Like alkaline hydrothermal vents,

275-401: A complex community of microorganisms that includes Spirulina , Calothrix , diatoms and other single-celled eukaryotes , and grazing insects and protozoans. As temperatures drop close to those of the surroundings, higher plants appear. Alkali chloride hot springs show a similar succession of communities of organisms, with various thermophilic bacteria and archaea in the hottest parts of

330-679: A depth of at least 1.5 kilometres (0.93 mi), and contain specified amounts of minerals such as sulphur, sodium, iron, or magnesium. When onsen water contains distinctive minerals or chemicals, establishments often display what type of water it is, in part because the specific minerals found in the water have been thought to provide health benefits. Types include sulfur onsen ( 硫黄泉 , iō-sen ) , sodium chloride onsen ( ナトリウム泉 , natoriumu-sen ) , hydrogen carbonate onsen ( 炭酸泉 , tansan-sen ) , and iron onsen ( 鉄泉 , tetsu-sen ) . Exactly when humans first began bathing in onsen in Japan

385-408: A form of opal (opal-A: SiO 2 ·nH 2 O ). This process is slow enough that geyserite is not all deposited immediately around the vent, but tends to build up a low, broad platform for some distance around the spring opening. Acid sulfate hot springs are fed by hydrothermal fluids rich in hydrogen sulfide ( H 2 S ), which is oxidized to form sulfuric acid , H 2 SO 4 . The pH of

440-474: A hot spring. However, even in areas that do not experience volcanic activity, 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 rock. This generally takes place along faults , where shattered rock beds provide easy paths for water to circulate to greater depths. Much of

495-424: A range of possible hot spring chemistries. Alkaline chloride hot springs are fed by hydrothermal fluids that form when groundwater containing dissolved chloride salts reacts with silicate rocks at high temperature. These springs have nearly neutral pH but are saturated with silica ( SiO 2 ). The solubility of silica depends strongly upon temperature, so upon cooling, the silica is deposited as geyserite ,

550-418: A slow process of thermal conduction , but in volcanic areas, the heat is carried to the surface more rapidly by bodies of magma. A hot spring that periodically jets water and steam is called a geyser . In active volcanic zones such as Yellowstone National Park , magma may be present at shallow depths. If a hot spring is connected to a large natural cistern close to such a magma body, the magma may superheat

605-475: A source of energy. In contrast with " black smokers " (hydrothermal vents on the ocean floor), hot springs similar to terrestrial hydrothermal fields at Kamchatka produce fluids having suitable pH and temperature for early cells and biochemical reactions. Dissolved organic compounds were found in hot springs at Kamchatka . Metal sulfides and silica minerals in these environments would act as photocatalysts. They experience cycles of wetting and drying which promote

SECTION 10

#1732858629873

660-469: A spring with water between 20 and 50 °C (68 and 122 °F). Water issuing from a hot spring is heated geothermally , that is, with heat produced from the Earth's mantle . This takes place in two ways. In areas of high volcanic activity, magma (molten rock) may be present at shallow depths in the Earth's crust . Groundwater is heated by these shallow magma bodies and rises to the surface to emerge at

715-429: A swimming suit in their mixed baths. Onsen guests generally bring a small towel with them to use as a wash cloth. The towel can also provide a modicum of modesty when walking between the washing area and the baths. Some onsen allow one to wear the towel into the baths, while others have posted signs prohibiting this, saying that it makes it harder to clean the bath. It is against the rules to immerse or dip towels in

770-417: A type of extremophile that thrives at high temperatures, between 45 and 80 °C (113 and 176 °F). Further from the vent, where the water has had time to cool and precipitate part of its mineral load, conditions favor organisms adapted to less extreme conditions. This produces a succession of microbial communities as one moves away from the vent, which in some respects resembles the successive stages in

825-476: Is a popular form of domestic tourism in Japan. During the bubble economy of the 1980s, there was a " onsen boom." Although the number of overnight guests at hot spring resorts has decreased slightly since the boom, travel to such onsen towns as a relaxing getaway is still popular among Japanese people. Traditionally, men and women bathed together at both onsen and sentō communal bathhouses, but gender separation has been enforced at most institutions since

880-425: Is believed to have unique benefits. Carbonated springs, for example, are believed to lead to smooth skin. Onsen facilities often advertise various health and beauty benefits they claim their water to provide. Water at some onsen facilities is drinkable. Onsen water should only be consumed if it is confirmed to be safe to drink by the prefecture. The water should be obtained from a designated drinking source that

935-479: Is covered with microbial mats 1 centimetre (0.39 in) thick that are dominated by cyanobacteria , such as Spirulina , Oscillatoria , and Synechococcus , and green sulfur bacteria such as Chloroflexus . These organisms are all capable of photosynthesis , though green sulfur bacteria produce sulfur rather than oxygen during photosynthesis. Still further from the vent, where temperatures drop below 45 °C (113 °F), conditions are favorable for

990-410: Is no universally accepted definition of a hot spring. For example, one can find the phrase hot spring defined as 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. The US NOAA Geophysical Data Center defines a "warm spring" as

1045-434: Is often located directly outside a facility's sauna to allow users to quickly cool down. The cycle of entering hot baths, saunas, and cold baths at an onsen facility is sometimes referred to as totonou (ととのう) and is believed to be refreshing and to have health benefits. Hot spring Hot spring water often contains large amounts of dissolved minerals. The chemistry of hot springs ranges from acid sulfate springs with

1100-498: Is required. 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 , Hungary , Iceland , Iran , Japan , New Zealand , Brazil , Peru , Serbia , South Korea , Taiwan , Turkey , and the United States , but there are hot springs in many other places as well: Domestic tourism Too Many Requests If you report this error to

1155-1181: Is separate from the water which is bathed in. The often mineral-rich onsen water is believed to have benefits such as treating iron-deficiency anemia or constipation . Article 18, paragraph 1 of the Japanese Hot Springs Act publishes guidance on contraindications and cautions for bathing in hot springs, and drinking their respective waters. Although millions of Japanese bathe in onsen every year with few noticeable side effects, there are still potential side effects to onsen usage, such as aggravating high blood pressure or heart disease. Legionella bacteria have been found in some onsen with poor sanitation. For example, 295 people were infected with Legionella and seven died at an onsen in Miyazaki Prefecture in 2002. Revelations of poor sanitary practices at some onsen have led to improved regulation by hot-spring communities to maintain their reputation. There have been reports of infectious disease found in hot bodies of water worldwide, such as various Naegleria species. While studies have found

SECTION 20

#1732858629873

1210-458: Is unknown, but historical records show it has a history of at least about 1,300 years. Many of the earliest records of onsen bathing document Japanese Emperors or members of the imperial family staying at onsen for long periods of time. At the time, onsen were thought to be sacred and to have healing properties. It is now believed those who traveled to onsen in these early records were seeking cures to disease or other ailments by bathing in

1265-568: The Homeric Age of Greece (ca. 1000 BCE), baths were primarily for hygiene, but by the time of Hippocrates (ca. 460 BCE), hot springs were credited with healing power. The popularity of hot springs has fluctuated over the centuries since, but they are now popular around the world. Because of both the folklore and the claimed medical value attributed to some hot springs, they are often popular tourist destinations, and locations for rehabilitation clinics for those with disabilities . However,

1320-528: The onsen bath water, since this can be considered unclean. People normally set their towels off to the side of the water when enjoying the baths, or place their folded towels on top of their heads. By 2015, around half (56%) of onsen operators had banned bathers with tattoos from using their facilities. The original reason for the tattoo ban was to keep out yakuza and members of other crime gangs who traditionally have elaborate full-body decoration. However, tattoo-friendly onsen do exist. A 2015 study by

1375-695: The onsen water. This ancient practice of bathing in onsen to cure illnesses, often for long periods such as a week, is referred to as tōji ( 湯治 ). Some of the oldest onsen in Japan are considered to be Dogo Onsen in Ehime Prefecture , Shirahama Onsen in Wakayama Prefecture , and Arima Onsen in Hyogo Prefecture . Until around the Edo period , onsen had close religious ties to Buddhism with temples often being built near onsen sources. During

1430-449: The Edo period, however, onsen began to gain popularity among the general population thanks in part to depictions of the hot springs in ukiyo-e . It is also during this period that the use of onsen shifted from being primarily for religious and healing reasons to being used for bathing for cleanliness and socializing. In modern times, traveling to hot spring resort towns ( 温泉街 , onsen-gai )

1485-495: The Hakuba Happo hot spring goes through serpentinization, suggesting methanogenic microbial life possibly originated in similar habitats. A problem with the hot spring hypothesis for an origin of life is that phosphate has low solubility in water. Pyrophosphite could have been present within protocells, however all modern life forms use pyrophosphate for energy storage. Kee suggests that pyrophosphate could have been utilized after

1540-585: The Japan National Tourism Organisation found that more than 30% of onsen operators at hotels and inns across the country will not turn someone with a tattoo away; another 13% said they would grant access to a tattooed guest under certain conditions, such as having the tattoo covered up. Some towns have many tattoo-friendly onsen that do not require guests to cover them up. Two such towns are Kinosaki Onsen in Hyōgo and Beppu Onsen in Ōita. With

1595-546: The Late Heavy Bombardment would not have caused cratering on Earth as they would produce fragments upon atmospheric entry. The meteors are estimated to have been 40 to 80 meters in diameter however larger impactors would produce larger craters. Metabolic pathways have not yet been demonstrated at these environments, but the development of proton gradients might have been generated by redox reactions coupled to meteoric quinones or protocell growth. Metabolic reactions in

1650-676: The Wood-Ljungdahl pathway and reverse Krebs cycle have been produced in acidic conditions and thermophilic temperatures in the presence of metals which is consistent with observations of RNA mostly stable at acidic pH. Hot springs have been enjoyed by humans for thousands of years. Even macaques are known to have extended their northern range into Japan by making use of hot springs to protect themselves from cold stress. Hot spring baths ( onsen ) have been in use in Japan for at least two thousand years, traditionally for cleanliness and relaxation, but increasingly for their therapeutic value. In

1705-414: The baths and must be completely nude. However, there are some onsen that allow both men and women to enter together but require swimsuits. Many of these mixed onsen resemble more of a pool or waterpark than the traditional idea of an onsen . In 2016, The Japan Times reported that guests were not normally allowed to wear swimsuits in the baths. However, some modern onsen required their guests to wear

Onsen - Misplaced Pages Continue

1760-901: The baths daily. These precautions as well as proper onsen usage (i.e. not placing the head underwater, washing thoroughly before entering the bath) greatly reduce any overall risk to bathers. Voyeurism is reported at some onsen . In 2016, The Japan Times reported that this was mitigated in some prefectures of Japan where nude mixed bathing is not permitted, and that visitors must wear swimsuits . In 2021, several people were arrested in connection with an organized group accused of taking photos of women in open-air baths. In addition to typical large public baths ( 大浴場 , daiyokujō ) and outdoor baths ( 露天風呂 , roten-buro ), there are various other methods of experiencing onsen that can be found at various facilities throughout Japan. Examples include: Saunas are also sometimes located at onsen bathing facilities. A relatively cold bath called mizu-buro (水風呂)

1815-520: The emergence of enzymes. Dehydrated conditions would favor phosphorylation of organic compounds and condensation of phosphate to polyphosphate. Another problem is that solar ultraviolet radiation and frequent impacts would have inhibited habitability of early cellular life at hot springs, although biological macromolecules might have undergone selection during exposure to solar ultraviolet radiation and would have been catalyzed by photocatalytic silica minerals and metal sulfides. Carbonaceous meteors during

1870-408: The evolution of early life. For example, in a bicarbonate hot spring, the community of organisms immediately around the vent is dominated by filamentous thermophilic bacteria , such as Aquifex and other Aquificales , that oxidize sulfide and hydrogen to obtain energy for their life processes. Further from the vent, where water temperatures have dropped below 60 °C (140 °F), the surface

1925-555: The fluids is thereby lowered to values as low as 0.8. The acid reacts with rock to alter it to clay minerals , oxide minerals , and a residue of silica. Bicarbonate hot springs are fed by hydrothermal fluids that form when carbon dioxide ( CO 2 ) and groundwater react with carbonate rocks . When the fluids reach the surface, CO 2 is rapidly lost and carbonate minerals precipitate as travertine , so that bicarbonate hot springs tend to form high-relief structures around their openings. Iron-rich springs are characterized by

1980-522: The formation of biopolymers which are then encapsulated in vesicles after rehydration. Solar UV exposure to the environment promotes synthesis to monomeric biomolecules. The ionic composition and concentration of hot springs (K, B, Zn, P, O, S, C, Mn, N, and H) are identical to the cytoplasm of modern cells and possibly to those of the LUCA or early cellular life according to phylogenomic analysis. For these reasons, it has been hypothesized that hot springs may be

2035-629: The groundwater originates as rain and snow ( meteoric water ) falling on the nearby mountains, which penetrates a particular formation ( Hollis Quartzite ) to a depth of 3,000 feet (910 m) and is heated by the normal geothermal gradient. Because heated water can hold more dissolved solids than cold water, the water that issues from hot springs often has a very high mineral content, containing everything from calcium to lithium and even radium . The overall chemistry of hot springs varies from alkaline chloride to acid sulfate to bicarbonate to iron-rich , each of which defines an end member of

2090-448: 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. The major heat-producing isotopes in the Earth are potassium-40 , uranium-238 , uranium-235 , and thorium-232 . In areas with no volcanic activity, this heat flows through the crust by

2145-669: The high concentrations of ionic solutes there would inhibit the formation of membranous structures. David Deamer and Bruce Damer note that these hypothesized prebiotic environments resemble Charles Darwin 's imagined "warm little pond". If life did not emerge at deep sea hydrothermal vents, rather at terrestrial pools, extraterrestrial quinones transported to the environment would generate redox reactions conducive to proton gradients. Without continuous wet-dry cycling to maintain stability of primitive proteins for membrane transport and other biological macromolecules, they would go through hydrolysis in an aquatic environment. Scientists discovered

2200-407: 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). In many countries, like Japan, it is required to enter the hot spring with no clothes on, including swimwear. Often there are different facilities or times for men and women, but mixed onsen do exist. In some countries, if it is a public hot spring, swimwear

2255-414: The hot spring. This leads to a runaway condition in which a sizable amount of water and steam are forcibly ejected from the hot spring as the cistern is emptied. The cistern then refills with cooler water, and the cycle repeats. Geysers require both a natural cistern and an abundant source of cooler water to refill the cistern after each eruption of the geyser. If the water supply is less abundant, so that

Onsen - Misplaced Pages Continue

2310-434: The increase in foreign customers due to growing tourism, some onsen that previously banned tattoos are loosening their rules to allow guests with small tattoos to enter, provided they cover their tattoos with a patch or sticking plaster. There are various health benefits attributed to bathing in onsen . Onsen are particularly renowned for their relaxing and therapeutic effects . These effects are due to properties such as

2365-407: The number of traditional public baths has decreased, but the number and popularity of hot spring resort towns ( 温泉街 , onsen-gai ) have increased since the end of Second World War . Baths may be either publicly run by a municipality or privately, often connecting to a lodging establishment such as a hotel, ryokan , or minshuku . The presence of an onsen is often indicated on signs and maps by

2420-511: The obvious impracticality of placebo-controlled studies (in which a patient does not know if they are receiving the therapy). As a result, the therapeutic effectiveness of hot spring therapy remains uncertain. 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. Some hot springs microbiota are infectious to humans: The customs and practices observed differ depending on

2475-599: The opening of Japan to the West during the Meiji Restoration . Mixed bathing ( 混浴 , kon'yoku ) is currently banned in Japanese public baths. Depending on the prefecture and local ordinances, children seven years old and younger may be exempt from this ban. Private onsen called "family baths" ( 家族風呂 , kazokuburo ) can be found in many locations throughout Japan. These can be reserved and used for mixed bathing. As at

2530-658: The place of origin of life on Earth. The evolutionary implications of the hypothesis imply a direct evolutionary pathway to land plants. Where continuous exposure to sunlight leads to the development of photosynthetic properties and later colonize on land and life at hydrothermal vents is suggested to be a later adaptation. Recent experimental studies at hot springs support this hypothesis. They show that fatty acids self-assemble into membranous structures and encapsulate synthesized biomolecules during exposure to UV light and multiple wet-dry cycles at slightly alkaline or acidic hot springs, which would not happen at saltwater conditions as

2585-675: The presence of Naegleria in hot spring waters, Naegleria fowleri , responsible for numerous fatal cases of primary amoebic meningoencephalitis around the world, has not been found to be present in the water at onsen . Nevertheless, fewer than five cases have been seen historically in Japan, although not conclusively linked to onsen exposure. Many onsen display notices reminding anyone with open cuts, sores, or lesions not to bathe. Additionally, in recent years onsen are increasingly adding chlorine to their waters to prevent infection, although many onsen purists seek natural, unchlorinated onsen that do not recycle their water but instead clean

2640-537: The presence of microbial communities that produce clumps of oxidized iron from iron in the hydrothermal fluids feeding the spring. Some hot springs produce fluids that are intermediate in chemistry between these extremes. For example, mixed acid-sulfate-chloride hot springs are intermediate between acid sulfate and alkaline chloride springs and may form by mixing of acid sulfate and alkaline chloride fluids. They deposit geyserite, but in smaller quantities than alkaline chloride springs. Hot springs range in flow rate from

2695-599: The scientific basis for therapeutic bathing in hot springs is uncertain. Hot bath therapy for lead poisoning was common and reportedly highly successful in the 18th and 19th centuries, and may have been due to diuresis (increased production of urine) from sitting in hot water, which increased excretion of lead; better food and isolation from lead sources; and increased intake of calcium and iron. Significant improvement in patients with rheumatoid arthritis and ankylosing spondylitis have been reported in studies of spa therapy, but these studies have methodological problems, such as

2750-562: The symbol ♨, the kanji 湯 ( yu , meaning "hot water"), or the simpler phonetic hiragana character ゆ ( yu ). According to the Japanese Hot Springs Act ( 温泉法 , Onsen Hō ) , onsen is defined as "hot water, mineral water, and water vapor or other gas (excluding natural gas of which the principal component is hydrocarbon ) gushing from underground". The law states that mineralized hot spring water that feeds an onsen must be at least 25 °C (77 °F) originating at

2805-833: The temperature, pressure, and mineral composition of the water. A 2014 study conducted in Beppu , a city famous for its onsen , found that regular bathing in onsen has various health benefits such as lowering blood pressure , improving circulation and cardiovascular health, reducing chronic pain and fatigue, and lowering the rate of depression . A survey conducted in Atami , another city famous for its onsen , found that individuals with onsen in their homes were less likely to take blood pressure medication than those without onsen . There are various types of onsen including carbonated springs, iron -containing springs, acidic springs, strong-smelling sulfur springs, among others. Each type of onsen

SECTION 50

#1732858629873

2860-479: The tiniest "seeps" to veritable rivers of hot water. Sometimes there is enough pressure that the water shoots upward in a geyser , or fountain . 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. Springs with high flow rates include: Hot springs often host communities of microorganisms adapted to life in hot, mineral-laden water. These include thermophiles , which are

2915-490: The vent. Acid sulfate hot springs show a somewhat different succession of microorganisms, dominated by acid-tolerant algae (such as members of Cyanidiophyceae ), fungi , and diatoms. Iron-rich hot springs contain communities of photosynthetic organisms that oxidize reduced ( ferrous ) iron to oxidized ( ferric ) iron. Hot springs are a dependable source of water that provides a rich chemical environment. This includes reduced chemical species that microorganisms can oxidize as

2970-443: The water in the cistern, raising its temperature above the normal boiling point. The water will not immediately boil, because the weight of the water column above the cistern pressurizes the cistern and suppresses boiling. However, as the superheated water expands, some of the water will emerge at the surface, reducing pressure in the cistern. This allows some of the water in the cistern to flash into steam, which forces more water out of

3025-479: The water is boiled as fast as it can accumulate and only reaches the surface in the form of steam , the result is a fumarole . If the water is mixed with mud and clay , the result is a mud pot . An 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). Here

#872127