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Lithium is an ideal material for green energy and lightweight alloys, and has been valued by many countries as an important strategic resource. Many hot springs, are rich in Li. However, hot springs are mainly distributed in remote areas such as Xizang and Yunnan, where the cost of sample transportation and laboratory testing is high and the efficiency is low, so the exploration of lithium resources urgently needs the support of on-site analysis technology. Hot spring water generally contains high concentrations of sodium, potassium and other elements, and the matrix effect is significant. In this study, the wavelength of the characteristic Li spectral line was set at 670.78nm. The analytical method for on-site determination of Li in hot spring water samples was established by a self-developed portable Li-K analyzer with a negative filter using the standard curve and standard addition methods. The experimental results show that when the electrolyte is 1.5% hydrochloric acid, the working current is 70mA and the sample flow rate is 3.0mL/min, the detection limit of Li is 4.07μg/L, and the measured precision (RSD) is better than 2%. The hot spring water samples were tested by standard addition, and the spiked recoveries were 81.6% to 115.9%. When the matrix composition of hot spring water samples is simple, accurate analysis results can be obtained by directly using the standard curve method. When the matrix composition of the sample is complex or the matrix concentration is high, the matrix effect can be effectively reduced by the standard addition method, and the analysis results obtained are relatively more accurate, which is suitable for the analysis of lithium content in hot spring water with different matrix types. [ABSTRACT FROM AUTHOR]

This study focused on free carbon dioxide (H2CO3) contained in volcanic hot spring water. It was clarified whether free carbon dioxide can be emitted into the atmosphere and increase the CO2 concentration in greenhouses by using the incubation method. Factors influencing the increase in CO2 concentration were identified based on implementation time in a demonstration experiment, temperature and humidity in the incubator, the amount of hot spring water, and the contact area between the hot spring water and the air. An incubator with an inner volume of 2.17 × 107 mm3 was used in this study. The results showed that unrelated factors were the implementation time in the demonstration experiment, temperature, and humidity. There was a relationship with the amount of hot spring water. The increment of CO2 concentration in the air by free carbon dioxide increased proportionally by increasing the amount of water. Free carbon dioxide contained in hot spring water can be utilized by considering the volume of facility horticulture and plant factories. The ideal methods for utility are to replace the hot spring water every few minutes and to increase the contact area between the air and the hot spring water. [ABSTRACT FROM AUTHOR]

The objective of this research was to test hot spring water as a source of salt to improve tomato quality under the hydroponic system. This research was conducted at Yamagata University, in Japan from February to July 2017. Salt stress was induced using salts of hot spring wastewater collected from Yupoka Onsen (Tsuruoka, Japan). The treatments were EC 2, 4, 8 12, and 16 mS/cm which were arranged in a Randomized Complete Block Design (RCBD) with five replications. Tomato plants were grown at EC 2 until flowering and then subjected to different EC concentrations until harvesting. The data were collected on plant growth parameters and fruit quality. Fruits were harvested at the red stage until the 5th truss. The results showed that fruits' Soluble Solids Content, organic acid, Nitrate contents and Sugar: Acid ratio increased significantly at EC 16 mS/cm and in the upper trusses compared to EC 2 and in the lower trusses. In contrast, fruit weight significantly decreased at EC 16 mS/cm and in upper trusses. Leaf thickness, size and SPAD, and specific leaf weight significantly declined at EC 16 mS/cm and upper leaves compared to EC 2 and in lower leaves. Plant height started to decline significantly after three weeks of treatment at EC 16 compared to EC 2. [ABSTRACT FROM AUTHOR]

In addition to an analytical result of two gas samples, published geological and geochemical data on the Isobe gas field, which had produced CO2 commercially during about 30 years, are examined in this paper from the viewpoint of petroleum geology. Chemical and carbon isotopic compositions of gases from the field indicate that CO2 is magmatic origin and has no relationship with hydrocarbons which are derived from the thermal decomposition of organic matters. Faults are ascending paths of CO2, which is driving force for hot spring waters. Chemical and isotopic compositions of associated waters with gases which are used as hot spring waters indicate that the waters are fossil sea waters which were entrapped during deposition and undergone diagenetic alteration. Higher temperatures of the waters estimated by the Mg-Li geothermometer than a bottom temperature at 1,500 m depth suggest that the waters are formed in deeper parts and derived from there. [ABSTRACT FROM AUTHOR]

Investigations of the hot spring water and gas in the volcanic region are involved in assessing geothermal resources and understanding groundwater circulation, volcano, and earthquake activities. The origins of water and gas of the hot springs, lakes, rivers, and rain in the Arxan volcanic region (AVR), northeastern (NE) China, were investigated by conducting a field survey and geochemical analysis. The low electrical conductivity (40–835 μS/cm) and low total dissolved solids (TDS, 23.83–540.00 mg/L) of the water samples indicate that they are fresh water. δ18O and δD values of the water samples range from −4.1% to −16.0% and from −61.3% to −119.9%, respectively. Enrichment of heavy isotopes in the rainwater and the crater lake waters was caused by evaporation. The component H2O of the water samples predominantly originated from the meteoric water, with less than 1 vol% contributed by deep-earth fluids. Ions in the rain sample were predominantly derived from sea salt and continental aerosol. Ions in the surface water samples had multiple origins (mineral dissolution, atmospheric, and anthropogenic sources). While the ions in the hot spring water were predominantly derived from both the dissolution of rocks and deep-earth fluids, the latter contributed 73%–87% of Cl− and 86%–99% of Na+ to the hot spring waters. Gases from the hot springs were composed of more than 95% N2 and less than 5% O2 and Ar, with 3He/4He ratios of 0.14–1.17 RA (RA=1.4×10−6). Excess N2, Ar, He, and CO2 of the hot springs were mainly derived from both the crust and upper mantle. About 3%–23% of the total He in the bubbling gases from the crater lake waters and hot springs is derived from the mantle, implying a supplement of heat energy from the mantle to the geothermal systems. Significantly, about 12% of the He dissolved in the Budonghe water is derived from the mantle, indicating that plenty of mantle-derived heat transported by deep-earth fluids keeps the river water from freezing. Our results indicate that Cl and Na ions and 3He/4He ratio are the feasible geochemical indicators for source partitioning of geothermal fluids.

Protein consists of amino acids, which are essential substances for organisms. Amino acids are important materials for origin and chemical evolution of life. Extremophiles live in hot spring water. In this research, we attempt synthesis of amino acids in natural hot spring water. Hot spring water was obtained from Onogawa hot spring (Yamagata prefecture) and Owani hot spring (Aomori prefecture). Formaldehyde and inorganic salts were added to the hot spring water. Then, the bubbling treatment was carried out with hydrogen sulfide against the water. Although amino acids have been prepared from cyanides by the Strecker reaction in the presence of acid catalysts, amino acids were synthesized in the neutral hot spring water under no cyanides in this study. Further, we discuss function of iridium as a catalyst for chemical reactions in the hot spring water. A set of reactions in hot spring water may be occurred from primitive earth to the present. [ABSTRACT FROM AUTHOR]

Removal of low-concentration fluoride in natural water is an important issue all over the world. Japan is a volcanic country with many hot springs, and the removal of low-concentration fluoride from hot spring drainage is desired. In this study, we attempted to prepare a novel adsorbent with high selective removal ability of fluoride from zircon sand using mechanochemical treatment, and applied it for removing fluoride from hot spring water. Mechanochemical treatment of zircon sand was carried out using a planetary ball mill, and fluoride removal of the product was examined using fluoride aqueous solution and hot spring water. The hot spring water is collected from one of the hot spring in Japan, and a typical sulfuric acid hot spring water pH 2 including high contents of SO4 2-(12000 mg• L-1) and Cl- (5000 mg • L-1) with 11 - 15 mg • L-1. Fluoride can be adsorbed selectively from hot spring water below Japanese effluent standard for fluoride (8.0 mg • L-1. Fluoride can be adsorbed selectively from hot spring water below Japanese effluent standard for fluoride (8.0 mg • L-1). [ABSTRACT FROM AUTHOR]

Electrocardiogram (ECG) electrodes are conductive pads applied to the skin to measure cardiac activity. Ag/AgCl electrodes are the commercial product which widely used to obtain ECGs. When monitoring the ECG in a hot spring, Ag/AgCl electrodes must be waterproofed; however, this is time-consuming, and the adhesive may tear the skin on removal. For solving the problem, we developed the carbon pencil lead (CPL) electrodes for use in hot springs. Both CPL and Ag/AgCl electrodes were connected to ECG100C's cables. The Performance was evaluated in three conditions as following: hot spring water with and without bubble, and in cold water. In each environment, the procedure was followed by three different protocols that are recording from the dry condition, hot spring water immersion with and without movement, post hot spring water condition. Under dry and wet conditions, both electrodes can obtain the waveform of the ECG signal in which all PQRST waves were identifiable. Nevertheless, the signal quality of both types of electrodes was different in water immersion with and without movement. The overall morphology obtained by Ag/AgCl electrodes was unstable higher than that of CPL electrodes in immersion without movement condition. The CPL electrodes provided better ECG waveform quality compared to Ag/AgCl electrodes in which the ECG signal had high waveforms distortion in water immersion with movement condition. [ABSTRACT FROM AUTHOR]

Phreatic eruptions at Nakamachineshiri and Ponmachineshiri reflect the vigorous fumarolic and hydrothermal activities of Meakandake volcano. Thus, phreatic eruptions are likely to reoccur in the future, and hydrothermal systems should be understood to mitigate the risks of potential future hazards. Here, we reveal the results of long-term geochemical monitoring of hot spring waters and fumarolic gases since 1986 and discuss the chemical and temperature changes in hot spring waters, discharging at the foot, related to volcanic unrest. In Nakamachineshiri, related to the increase in seismic and fumarolic activity since 2019, the HCl concentration of the fumarolic gas has increased, and δD and δ18O values have also increased to approach those of the andesitic water. Simultaneously, with the increase in fumarolic and hydrothermal activity, the temperature and Cl concentration of the Meakan Onsen (MO) hot spring water discharged at the western foot of Nakamachineshiri have increased. The chemical characteristics of the fumarolic gas and MO water indicate that they were derived from a hydrothermal system in the shallow subsurface of Nakamachineshiri. Thus, we can consider that the temperature and chemical increases in the MO water represent activation of the system, and monitoring the MO water provides important information for understanding the present state of Nakamachineshiri. At Ponmachineshiri, phreatic eruptions occurred in 1988, 1996, 1998, 2006, and 2008, and seismic and fumarolic activity has sometimes increased since 1986 when we began our monitoring program. At the western foot of Ponmachineshiri, hot spring water is discharged at Yunotaki (YNT_U and YNT_L) and Lake Onneto (ONT). The results of our monitoring suggest that the YNT_U water is formed by mixing thermal water with a high HCO 3 molar ratio (HCO 3 -type) and thermal water containing Cl and SO 4 (Cl-SO 4 -type), which causes temperature and chemical changes related to the mixing ratio of these thermal waters related to volcanic unrest, especially increases in seismic activity. The Cl and SO 4 concentrations in the ONT water began to increase approximately two years before the phreatic eruptions and increase in fumarolic activity. Such chemical increases can be explained by the increase in the supply of Cl-SO 4 -type thermal water and are likely to indicate precursor changes in volcanic unrest. Therefore, we expect to utilize these hot spring waters to understand the present state of Ponmachineshiri and detect precursor changes to future volcanic unrest. • Long-term monitoring for hot spring waters and fumarolic gases has been performed at Meakandake volcano. • Chemical and thermal changes related to volcanic unrest were detected in hot spring waters discharged at the foot. • Monitoring for hot spring waters is useful to understand the present state of volcanic activity. [ABSTRACT FROM AUTHOR]

Study region: Beppu City, Oita Prefecture, Japan was selected as a site of this study. Study focus: This study aims to provide quantitative guidelines necessary for capacity building among various stakeholders to minimize water-energy conflicts in developing mini/micro hydropower (MHP), a baseload renewable energy that is socially necessary, not only to reduce greenhouse gas emissions but also to vitalize local economies by creating jobs related to MHP operations. Using three different methods to calculate river water levels and discharges, the potential power generation by MHP was estimated for six rivers in Beppu City. New hydrological insights: Our results show that installation of MHP facilities can provide stable electricity for tens to hundreds of residents in local communities along the rivers. However, the results are based on the existing infrastructure, such as roads and electric lines. This means that greater potential is expected if additional infrastructures are built to develop further MHP facilities. On the other hand, in Japan, river laws and irrigation right regulations currently restrict new entry by actors to rivers. Therefore, to further develop MHP, deregulation of the existing laws relevant to rivers and further incentives for business owners of MHP facilities, along with the current feed-in tariffs, are required. Meanwhile, possible influences to riverine ecosystems when installing new MHP facilities should also be taken into account.

In order to prevent various infectious diseases including legionellosis, the chlorination of hot spring bath water is essential. However, because of problems such as odor and changes in spring quality due to chlorine agents, it is difficult to maintain the original hot spring water. We asked 65 subjects (36 female, 29 male) to take a bath in bath water disinfected with electrolytic hypochlorite water and measured skin pH and stratum corneum water content, before and after the bathing, to compare the effects thereof on the skin. Compared with the case of sodium hypochlorite, the influence on the skin was considered to be comparable and it was found that electrolytic hypochlorite water actually had a tendency to increase the moisturizing effect. Furthermore, it was revealed, in the summary of the subjective evaluation after bathing, that the chlorine odor, which was despised in the case of sodium hypochlorite, was reduced with electrolytic hypochlorite water. It was indicated that skin problems such as redness and itching did not occur at all after bathing therewith and that it was safe to use electrolytic hypochlorite water for disinfecting bathtub water. Furthermore, based on the results of water quality analysis of the bathtub water, electrolytic hypochlorite water showed a tendency to be a reduction system, with a lower ORP than sodium hypochlorite. [ABSTRACT FROM AUTHOR]

Monitoring of surface displacement by satellite-based interferometric synthetic aperture radar (InSAR) analysis is an effective method for detecting land subsidence in areas where routes of leveling measurements are undeveloped, such as mountainous areas. In particular, InSAR-based monitoring around well-developed hot spring resorts, such as those in Japan, is useful for conserving hot spring resources. Hakone Volcano is one of the major hot spring resorts in Japan, and many hot spring wells have been developed in the Owakudani fumarole area, where a small phreatic eruption occurred in 2015. In this study, we performed an InSAR time series analysis using the small baseline subset (SBAS) method and ALOS/PALSAR scenes of the Hakone Volcano to monitor surface displacements around the volcano. The results of the SBAS-InSAR time series analysis show highly localized subsidence to the west of Owakudani from 2006–2011 when the ALOS/PALSAR satellite was operated. The area of subsidence was approximately 500 m in diameter, and the peak rate of subsidence was approximately 25 mm/year. Modeling using a point pressure source suggested that the subsidence was caused by a contraction at approximately 700 m above sea level (about 300 m below the ground surface). The rate of this contraction was estimated to be 1.04 × 104 m3/year. Hot spring water is collected from a nearby well at almost the same depth as the contraction source, and its main dissolved ion component is chloride ions, suggesting that the hydrothermal fluids are supplied from deep within the volcano. The land subsidence suggests that the fumarole activity is attenuating due to a decrease in the supply of hydrothermal fluids from deeper areas.

Background: In Tunisia, the use of hot spring waters for both health and recreation is a tradition dating back to Roman times. In fact, thermal baths, usually called "Hammam" are recommended as a therapeutic and prophylactic measure against many types of illness and toxicity. While the chemical concentration of thermal water is admittedly associated with its therapeutic effects, the inclusion in spa waters of efficient bioproduct additives produced by photosynthetic microorganisms and that act against oxidative stress may comprise a significant supplementary value for thermal centers. The aim of this study was to investigate the antioxidant potential of the Tunisian thermophilic cyanobacterium Leptolyngbya sp. and to determine its phytochemical constituents and phenolic profile. Methods: BME (Biomass Methanolic Extract), CME (Capsular polysaccharides Methanolic Extract) and RME (Releasing polysaccharides Methanolic Extract) of Leptolyngbya sp. were examined for their antioxidant activities by means of DPPH, hydroxyl radical scavenging and ferrous ion chelating assays. Their total phenols, flavonoids, carotenoids, Mycosporine-like amino acids (MAAs) and vitamin C contents, as well as their phenolic profiles were also determined. Results: BME has the highest content of phenols (139 ± 1.2 mg/g), flavonoids (34.9 ± 0.32 mg CEQ/g), carotenoids (2.03 ± 0.56 mg/g) and vitamin C (15.7 ± 1.55 mg/g), while the highest MAAs content (0.42 ± 0.03 mg/g) was observed in CME. BME presented both the highest DPPH and hydroxyl radical scavenging ability with an IC50 of 0.07 and 0. 38 mg/ml, respectively. The highest ferrous chelating capacity was detected in CME with an IC50 = 0.59 mg/ml. Phenolic profiles revealed the presence of 25 phenolic compounds with the existence of hydroxytyrosol, oleuropein, resveratrol and pinoresinol. Conclusion: The study demonstrated that the cyanobacterium Leptolyngbya sp. possesses abundant natural antioxidant products which may have prophylactic and therapeutic effects on many types of illness and toxicity. The present findings not only explain and reinforce the rationale behind traditional therapeutic practices in Tunisia in the exploitation of the country's hot springs, but support the addition of Leptolyngbya to thermal waters as a means to enhance the value and reputation of the curative nature of Tunisian thermal waters. [ABSTRACT FROM AUTHOR]

ABSTRACT Strain L-47T of a novel bacterial species belonging to the genus Legionella was isolated from a sample of hot spring water from Tokyo, Japan. The 16S rRNA gene sequences (1477 bp) of this strain (accession number AB899895) had less than 95.0% identity with other Legionella species. The dominant fatty acids of strain L-47T were a15:0 (29.6%) and the major ubiquinone was Q-12 (71.1%). It had a guanine-plus-cytosine content of 41.5 mol%. The taxonomic description of Legionella thermalis sp. nov. is proposed to be type strain L-47T (JCM 30970T = KCTC 42799T). [ABSTRACT FROM AUTHOR]

Uranium- and thorium-series isotopes are able to dissolve in hot spring waters and decay into radon, which could potentially cause health risk of the public. Besides, several environmental investigations can be carried out by measuring radon concentrations in hot spring waters. Accordingly, the measurement of radon in hot spring water is a significant issue. A practical method for measuring radon in hot spring water was developed by using a silicon semiconductor detector, RAD-7. The overall effect of detection efficiency and radon leakage of the measuring system were examined to calibrate the measured concentration of radon in hot spring waters. In addition, the effect of water temperature and pH on emanation of radon from standard 226Ra solutions as well as that of the measuring time on precision of the measurement were investigated. The correlation among temperature, pH and emanation of radon was then obtained. Further, the established method was applied to in-situ measurement to investigate the concentration of radon in hot spring waters from different geological areas in Taiwan. According to the percent error of the measurement, the measuring time for environmental samples was set as 50 min. The overall effect of radon leakage and detection efficiency of the measuring system was estimated to be 99.19 ± 7.47% with a standard rock source of 222Rn from NIST. Standard sources of 222Rn were prepared from 226Ra standard solutions with different pH values. The 226Ra standard solutions were sealed and stand for 38 days in a 250 mL vial specific for the RAD-7. After measured by the WAT250 mode of the RAD-7, the data were measured as (52.5 ± 8.9)%∼(83.6 ± 11.0)% of the prepared concentration of 222Rn (from 226Ra). The emanation rate of 222Rn from standard solution under pH 1.44–9.07 was (53.2 ± 6.9)% ∼(84.3 ± 11.1)% and decreased with pH to a minimum value at 7.00. Moreover, the effect of temperature increases with pH. High correlated trend curves (r2 = 0.9829–0.9999) for 222Rn emanation rate versus pH under different temperature were obtained. A smooth curved surface fitted by the MATLAB for emanation rate of 222Rn was accordingly derived. The 222Rn concentrations in waters of the Beitou Hot Spring (acid-digestion sulfate spring on sedimentary rock strata), Wulai Hot Spring (sodium bicarbonate spring on metamorphic rock strata), Choshuitan (sodium bicarbonate spring on mudstone strata) and Zhaori Hot Spring (acid-digestion sulfate spring on andesite strata) were measured with RAD-7 by WAT250 for 50 min and then calibrated by 222Rn emanation rate estimated above, which were 215 ± 37 (Bq/m3), 6797 ± 1073 (Bq/m3), 2124 ± 577 (Bq/m3) and 26644 ± 2768 (Bq/m3). • A practical method for measuring Rn in hot spring water was developed. • Correlation among water temperature, pH and emanation of Rn was obtained. • A smooth curved surface fitted by the MATLAB for Rn emanation was derived. • This method was applied to in-situ measurement of Rn in hot spring waters in Taiwan. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate the frequency of Legionella pneumophila in three hot spring water recreation areas by conventional culture on GVPC and by Real Time-PCR. No legionellae were isolated from the spring water upstream the distribution system suggesting strongly that the thermal area was the probable source of these pathogens. L. pneumophila was present at high level in some samples, reaching values of 8.2 × 103 CFU/l at the site C. We observed a low diversity among the 18 isolated Legionella strains according to 16S DNA analysis, since only L. pneumophila and Legionella londiniensis were identified. All of the L. pneumophila strains belong to five serogroups (1, 4, 5, 6 and 8). Pulsed-field gel electrophoresis analysis identified various genotypes among these serogroups and showed that these strains had pulsotypes distinct from L. pneumophila present in the CNRL Legionella-database. These environmental strains showed higher tolerance to heat shock stress at 48 °C than L. pneumophila clinical strain, which may explain their presence in warm waters. Our data suggested that potential pathogen legionellae are present in Tunisian medicalized thermal spas and emphasized the importance of adopting control measures to prevent infection. [Copyright &y& Elsevier]

Tritium and C concentration in hot spring water in Korea were determined. Tritium in the most hot spring samples could not detected and concentration range was <0.5-1.31 TU. And C contents were ranged 1.7-78.6 pMC. From the H and C analysis, we found some hot springs are mixed with recent groundwater and hot spring water ages were estimated from 1,940 to 32,800 years. And also, Ra and Ra were determined simultaneously in hot spring water, and some other radionuclides were also analyzed. Content distribution of Rn was 50-3,760 pCi/L, Ra was <0.003-0.15 Bq/L and Ra was below the detection limit. [ABSTRACT FROM AUTHOR]

In this study, we investigated the distribution of Legionella in sources of spring water and wastewater throughout Taiwan. Legionella were detected with culture method and PCR method from water samples, combined with molecular methods that allow the taxonomic identification of Legionella species. Factors associated with the distribution of Legionella including the physical-chemical and microbiological water quality characteristics were also measured. Legionella were detected in 18 of the 68 samples. Additionally, 16 of the 68 samples analyzed by polymerase chain reaction (PCR) and eight of the 68 samples evaluated using the culture method were found to be positive for Legionella. The Legionella species identified included Legionella pneumophila, unnamed Legionella genotypes, uncultured Legionella spp., and Legionella lytica. Legionella species were found in water with temperatures ranging from 10.0 to 50.6°C and with pH values ranging from 5.59 to 9.32. Significant differences (Mann-Whitney U test, P < 0.05) were observed in the presence/absence of Legionella in samples with different pH values when Legionella were detected by the culture method. The results of this survey confirmed that Legionella is ubiquitous in the water of spring recreational areas in Taiwan. Long-term investigations of the occurrence of Legionella in hot spring recreational areas throughout Taiwan are needed. [ABSTRACT FROM AUTHOR]

part of an epidemiological study on legionellosis, we attempted to isolate Legionella spp. from hot spring water and were able to isolate L. londiniensis HYKF-90505 (=JCM 16338), confirming that L. londiniensis inhabits hot spring water in Japan. To investigate the disease potential of L. londiniensis, we examined its ability to grow intracellularly within Acanthamoeba sp. JAC/E1 strain. The isolated HYKF-90505 was able to grow within Acanthamoeba sp. JAC/E1 strain, and we confirmed also that the HYKF-90505 strain showed cytotoxicity for cultured cells such as J774.1 (JCRB0018). However, in a culture of human U937 cells, the bacterial count was not increased by the intracellular growth of the HYKF-90505 strain. Cells infected for 24 h and stained using the Giménez method showed no intracellular growth of the HYKF-90505 strain. Thus, the isolate appears to be weakly pathogenic to humans. [ABSTRACT FROM AUTHOR]

New stable isotope and noble gas data obtained from fumarolic and bubbling gases and hot spring waters sampled from Deception Island, Antarctica, were analysed to constrain the geochemical features of the island's active hydrothermal system and magmatism in the Bransfield back-arc basin. The ³He/4He ratios of the gases (, 9.8 × 10-6), which are slightly lower than typical MORB values, suggest that the Deception Island magma was generated in the mantle wedge of a MORB-type source but the signature was influenced by the addition of radiogenic 4He derived from subducted components in the former Phoenix Plate. The N2/He ratios of fumarolic gas are higher than those of typical mantle-derived gases suggesting that N2 was added during decomposition of sediments in the subducting slab. The δ13C values of -5 to -6‰ for CO2 also indicate degassing from a MORB-type mantle source. The H2/Ar- and SiO2 geothermometers indicate that the temperatures in the hydrothermal system below Deception Island range from ∼150°C to ∼300°C. The δD and δ18O values measured from fumarolic gas and hot spring waters do not indicate any contribution of magmatic water to the samples. The major ionic components and δD-δ18O-δ34S values indicate that hot spring waters are a mixture of local meteoric water and seawater. Mn and SiO2 in spring waters were enriched relative to seawater reflecting water-rock interaction at depth. [ABSTRACT FROM AUTHOR]

A method for Ge determination in hot spring water and acid extracts from coal fly ash samples involving hydride generation, trapping and atomisation of the hydride generated from Ir-treated graphite tubes (GTs) has been developed. Hydride was generated from hydrochloric acid medium using sodium tetrahydroborate. Several factors affecting the hydride generation, transport, trapping and atomisation efficiency were studied by using a Plackett-Burman design. Results obtained from Plackett-Burman designs suggest that trapping and atomisation temperatures are the significant factors involved on the procedure. The accuracy was studied using NIST-1633a (coal fly ash) reference material. The detection limit of the proposed method was 2.4 μg l-1 and the characteristic mass of 233 pg was achieved. The Ge concentrations in fly ash and hot spring samples were between 6.25–132 μg g-1 and 12.84–36.2 μg l-1. [Copyright &y& Elsevier]

A hot spring water lake in Tateyama Hot Spring has a high content of silica and readily precipitates silica spheres and deposits of opal. Abundant fragments of naturally fallen wood impregnated with silica were found in the overflow stream of the lake. These silicifications resulted from the precipitation of silica spheres onto split surfaces or cell walls of the fallen wood. The textures of wood tissues are the same as those found on naturally silicified wood formed in the vicinity of volcanic regions in the geological record. These results explain the formation mechanism of certain naturally silicified wood fragments that seem to be formed under the same conditions as those found in the hot spring water.To confirm the silicification process, fresh wood pieces of alder wood (Alnus pendula Matsumura) were placed in the hot spring water stream. Experimental wood fragments were silicified to nearly 40% by weight over a period of 7 years by the deposition of amorphous silica spheres in cell lumina of wood tissue.This study reveals that silicified wood can form under suitable conditions in time periods as short as tens to hundreds of years, and contributes to the understanding of the mechanisms forming silicified wood. [Copyright &y& Elsevier]

• Chemical composition and hydrogen and oxygen isotopes of hot spring waters in Toyama were determined. • The origin and underground temperature condition for geothermal exploration were discussed. • High salinity groups of hot spring waters are a mixture of fossil sea water and meteoric water. • The low salinity groups are of meteoric origin. • There are high-temperature geothermal resources in the eastern area. The chemical compositions, including hydrogen and oxygen isotopes, of 35 hot spring waters in Toyama Prefecture, central Japan, were analyzed to examine their geochemical characteristics and geothermal resources. The hot spring water samples were classified into two groups: low and high chloride (Cl−) concentrations of less than and greater than 2000 mg/L, respectively. The samples in the low-salinity group were determined to be of meteoric origin and Ca2+–HCO 3 − type. The samples in the high-salinity group were determined to be of Na+–Ca2+–Cl− type and assumed to contain a mixture of fossil seawater and meteoric water. In the eastern area of the study region, the Na+/K+ and SiO 2 concentrations were lower and higher, respectively, than those in other areas, which corresponded to high-temperature geothermal resources. Thus, the subsurface information obtained in this study enabled effective use of the low to medium geothermal resources in Toyama Prefecture. [ABSTRACT FROM AUTHOR]

• Geothermal waters from a geothermal well in the vicinity of Yakedake volcano were monitored for 1 year for chemical and D, O, and Sr compositions. • The 87Sr/86Sr ratios of hot spring waters in Shinhirayu area are lower than those in the other districts reflecting the geologic formations. • Precipitation infiltrated into the Kasagatake Rhyolite formation where the thermal waters are enriched in Ca2+, K+ and Sr2+ by interaction with reservoir rocks. • The geothermal water from well No. 7 and hot spring waters in the study area are not in chemical equilibrium with the reservoir rocks. Geothermal waters from a 1,100-m-deep geothermal well (No. 7) in the vicinity of Yakedake volcano in Gifu Prefecture, central Japan, were monitored for 1 year for chemical and isotope (D, O, and Sr) composition to examine their source. Drill cuttings from the well and surrounding hot spring waters were also analyzed for 87Sr/86Sr ratios and chemical composition. Combining the calculated reservoir temperatures for geothermal waters from well No. 7 and the 87Sr/86Sr ratios obtained, we suggest a shallow source for the geothermal waters, such as the Cretaceous to Paleogene Kasagatake Rhyolites, and propose downward-flowing meteoric waters as dominant at depth where the geothermal waters are enriched in Ca2+, K+, and Sr2+ by the interaction with reservoir rock. The 87Sr/86Sr ratios of hot spring waters in the Shinhirayu area, west of well No.7, are lower than those in three adjacent areas (Nakao, Gamada, and Hirayu), reflecting differences between the geologic formations comprising the reservoir rocks. The geothermal water from well No. 7 and hot spring waters in the study area are not in chemical equilibrium with the reservoir rocks because the reservoirs are young and not strongly altered. [ABSTRACT FROM AUTHOR]

A study on the isolation and identification of bacterial flora from hot spring was carried out using water from Bentong hot spring in Pahang. In general most of the bacteria identified from the hot springs were from Bacillus sp. This was due to its ability to adapt to high temperature mainly by forming endospore. The objective of this study was to identify bacteria other than Bacillus that were able to survive in hot springs. Three hot spring pools were identified (A,B and C) with temperatures ranging from 36°C to 52°C and pH values between 7.88-8.65. This study has succesfully isolated two species of Gram positive cocci and three species of Gram negative bacilli. The two Gram positives were Streptococcus sp. and Staphylococcus sp. The three species of Gram negative rods were unidentified and were denoted as X, XI and XII. [ABSTRACT FROM AUTHOR]

Monitoring of surface displacement by satellite-based interferometric synthetic aperture radar (InSAR) analysis is an effective method for detecting land subsidence in areas where routes of leveling measurements are undeveloped, such as mountainous areas. In particular, InSAR-based monitoring around well-developed hot spring resorts, such as those in Japan, is useful for conserving hot spring resources. Hakone Volcano is one of the major hot spring resorts in Japan, and many hot spring wells have been developed in the Owakudani fumarole area, where a small phreatic eruption occurred in 2015. In this study, we performed an InSAR time series analysis using the small baseline subset (SBAS) method and ALOS/PALSAR scenes of the Hakone Volcano to monitor surface displacements around the volcano. The results of the SBAS-InSAR time series analysis show highly localized subsidence to the west of Owakudani from 2006–2011 when the ALOS/PALSAR satellite was operated. The area of subsidence was approximately 500 m in diameter, and the peak rate of subsidence was approximately 30 mm/year. Modeling using a point pressure source suggested that the subsidence was caused by a contraction at approximately 700 m above sea level (about 300 m below the ground surface). The rate of this contraction was estimated to be 1.04 × 104 m3/year. Hot spring water is collected from a nearby well at almost the same depth as the contraction source, and its main dissolved ion component is chloride ions, suggesting that the hydrothermal fluids are supplied from deep within the volcano. The land subsidence suggests that the fumarole activity is attenuating due to a decrease in the supply of hydrothermal fluids from deeper areas. [ABSTRACT FROM AUTHOR]

Background: Empirical evidences for efficacy of hot spring (HS) water in inflammatory skin disorders have not been substantiated with sufficient, immunological "hard evidence". Mageumsan HS water, characterized by its weakly-alkaline properties and low total dissolved solids content, has been known to alleviate various immune-inflammatory skin diseases, including atopic dermatitis (AD)., Objective: The trial attempted to quantitatively analyze in vitro expression levels of chemical mediators in cutaneous inflammation from HaCaT cell line treated with Mageumsan HS, and suggest the likely mode of action through which it exerts the apparent anti-inflammatory effects in AD., Methods: Using membrane-based human antibody array kit, customized to include 30 different, keratinocyte-derived mediator proteins, their expression levels (including interleukin [IL]-1, IL-6, IL-8, thymic stromal lymphopoietin, thymus and activation-regulated chemokine, and granulocyte macrophage colony-stimulating factor) were assessed in vitro . Selected key proteins were further quantified with enzyme-linked immunosorbent assay., Results: There was a clear pattern of overall suppression of the mediators, especially those noted for their pro-inflammatory role in AD (monocyte chemoattractant protein [MCP]-1, regulated on activation, normal T cell expressed and secreted, cutaneous T-cell-attracting chemokine, Eotaxin, and macrophage inflammatory protein-1α, etc.). Also, reduced expression of involucrin and cytokeratin 1 was also reduced in the HS-treated group., Conclusion: The present study has shown that Mageumsan HS water may exert its effects on inflammatory skin disorders through regulation of proinflammatory cytokines. These evidences are to be supported with further future investigations to elucidate immunological mechanism behind these beneficial effects of HS water in the chronically inflamed skin of AD., Competing Interests: CONFLICTS OF INTEREST: The authors have nothing to disclose.

Several factors influence bacteria biodiversity in hot springs. The impact of biotic and abiotic pathways on travertine deposition plays a key role in microbial ecology and in the final composition of the waterborne microbiota. The metabolism of some bacterial groups such as photoautotrophs or lithoautotrophs influences water chemistry, favoring carbonate precipitation processes. The role of microbial mats in mineral precipitation processes is not fully clarified. For the first time, a comprehensive metagenomic analysis has been undertaken in the historical Bullicame hot spring. Bacterial biodiversity was characterized and biomineralization activities were assigned to different genera. A higher biodiversity in mat samples compared to water samples was observed: Shannon index of 3.34 and 0.86, respectively. Based on the functional assignment of each Operational Taxonomic Unit, the bacteria involved in biologically- induced mineralization are prevalent in mat and released in the water. According to the principle that each geothermal water specimen has distinctive physic-chemical characteristics, our results suggest new interacting bio-actions within these ecosystems. The saturation index and the chemical composition, as the high concentration of sulfur species and HCO3, can be linked to create a selective environment where pioneer communities are able to live and shape the ecosystem.