Hot Springs Research Articles

Complete genome sequences of Thermus thermophilus strains isolated from Shirahama Hot Spring in Japan.

We isolated six Thermus thermophilus strains from Shirahama Hot Spring in Japan. Complete genome sequences, determined by combining Oxford Nanopore long-read and Illumina short-read sequence data, revealed that they showed >99.9% average nucleotide identities with each other and approximately 97% to the genome of the type strain HB8T.

Thermal profiles of Cicindelidia haemorrhagica (Coleoptera: Cicindelidae) activity in hot springs in Yellowstone National Park.

The wetsalts tiger beetle, Cicindelidia haemorrhagica (LeConte) (Coleoptera: Cicindelidae), is found in several active thermal hot spring areas in Yellowstone National Park (YNP) where substrate surface temperatures can exceed 50 °C. However, relationships between surface temperatures and the time adults spend on them remain poorly understood. Therefore, we characterized thermal profiles of Dragon Spring and Rabbit Creek, 2 thermally active research sites containing C. haemorrhagica in YNP, to quantify the time adults spend at different surface temperatures. We took 58 thermal video recordings of adults over 6 total days of observation ranging from 10 to 15min for each adult. Thermal video analysis results indicated a positive relationship between the total time adult beetles spent on surface temperatures from Dragon Spring and Rabbit Creek as temperatures increased from 20 °C. Once surface temperatures exceeded 40 °C, the total time spent at those surface temperatures declined. Adults were recorded on substrates exceeding 50 °C at one of the 2 research locations. Rabbit Creek had substantially more instances of adults present with surface temperatures exceeding 40 °C, including one individual on a surface temperature of 61.5 °C. There were 3 instances of beetles spending more than 4min at a particular surface temperature, all within the preferred range of 30-40 °C. Our thermal profile results and previous behavioral observations suggest that adults may be resistant to the heat produced from the thermal waters that influence the substrate temperatures but may not be subject to high surface temperatures as previously reported.

Microbial Ecology of an Arctic Travertine Geothermal Spring: Implications for Biosignature Preservation and Astrobiology.

Jotun springs in Svalbard, Norway, is a rare warm environment in the Arctic that actively forms travertine. In this study, we assessed the microbial ecology of Jotun's active (aquatic) spring and dry spring transects. We evaluated the microbial preservation potential and mode, as well as the astrobiological relevance of the travertines to marginal carbonates mapped at Jezero Crater on Mars (the Mars 2020 landing site). Our results revealed that microbial communities exhibited spatial dynamics controlled by temperature, fluid availability, and geochemistry. Amorphous carbonates and silica precipitated within biofilm and on the surface of filamentous microorganisms. The water discharged at the source is warm, with near neutral pH, and undersaturated in silica. Hence, silicification possibly occurred through cooling, dehydration, and partially by a microbial presence or activities that promote silica precipitation. CO2 degassing and possible microbial contributions induced calcite precipitation and travertine formation. Jotun revealed that warm systems that are not very productive in carbonate formation may still produce significant carbonate buildups and provide settings favorable for fossilization through silicification and calcification. Our findings suggest that the potential for amorphous silica precipitation may be essential for Jezero Crater's marginal carbonates because it significantly increases the preservation potential of putative martian organisms.

Microbial Ecology of an Arctic Travertine Geothermal Spring: Implications for Biosignature Preservation and Astrobiology.

Jotun springs in Svalbard, Norway, is a rare warm environment in the Arctic that actively forms travertine. In this study, we assessed the microbial ecology of Jotun's active (aquatic) spring and dry spring transects. We evaluated the microbial preservation potential and mode, as well as the astrobiological relevance of the travertines to marginal carbonates mapped at Jezero Crater on Mars (the Mars 2020 landing site). Our results revealed that microbial communities exhibited spatial dynamics controlled by temperature, fluid availability, and geochemistry. Amorphous carbonates and silica precipitated within biofilm and on the surface of filamentous microorganisms. The water discharged at the source is warm, with near neutral pH, and undersaturated in silica. Hence, silicification possibly occurred through cooling, dehydration, and partially by a microbial presence or activities that promote silica precipitation. CO2 degassing and possible microbial contributions induced calcite precipitation and travertine formation. Jotun revealed that warm systems that are not very productive in carbonate formation may still produce significant carbonate buildups and provide settings favorable for fossilization through silicification and calcification. Our findings suggest that the potential for amorphous silica precipitation may be essential for Jezero Crater's marginal carbonates because it significantly increases the preservation potential of putative martian organisms.

Comparative Assessment of Thermal Oils and Water as Working Fluids in Parabolic Trough Collectors for Enhanced Solar Power Generation

Abstract Examining the thermal behavior of specific working fluids, namely Syltherm800 and TherminolVP-1, in parabolic trough collectors (PTCs) is imperative for enhancing power generation. This study addresses a crucial gap by conducting computational fluid dynamics simulations through COMSOL Multiphysics software and experimental tests to explore the advantages of utilizing thermal oils over water as a working fluid in PTCs. Experimental tests were performed on a water-based PTC in Iraq to validate the numerical model, considering various operating conditions such as input temperature (323.15-423.15 K) and mass flow rates (0.00926-0.0556 kg/s). Key parameters including output temperature, thermal efficiency, useful heat, and total heat losses were evaluated. The numerical model was validated against experimental data, showing good agreement with an overall discrepancy of 1.7% for the current experiments and 3.18% for literature results. The results indicated that Syltherm800, particularly with a high mass flow rate, outperformed TherminolVP-1 and water in terms of overall thermal performance. The optimal PTC thermal efficiency was achieved in July with a mass flow rate of 0.0556 kg/s and an input temperature of 348.15 K. The optimal range for PTC thermal efficiency over four months was between 50% and 70%. The endorsement of thermal oils in PTCs is supported by their low vapor pressure, superior thermal stability, and extended lifespan.

PICTORIAL MAPS AND THE RISE OF MODERN RESORT IN ŌISO IN THE MID-MEIJI PERIOD

This study explores three pictorial maps produced in the mid-Meiji period (1868–1912) featuring Ōiso and the relationship between these maps and the rise of Ōiso as a modern resort. Ōiso was a town located on the highway Tōkaidō connecting Edo (or Tokyo after 1868) and Kyoto. It became a modern seaside resort after the late 1880s. Previous studies on visual and cartographic representations of towns and cities in Japan, for example, Kindai nihon no shikakuteki keiken [Visual experiences of modern Japan] (Nakanishi and Sekido 2008), have already narrowed the analytical focus and shifted away from the metropolises to provincial cities and hot spring towns. However, some questions, such as the social functions of these materials, remain unexplored. This study analyzes three maps and argues that these maps highlight Ōiso as an attractive place, particularly by featuring its villa residents from the high society. Visually, they resemble the conventional meisho zue [pictures of famous places] developed in the Edo period (1603-1867) and share with other city/town maps produced in the Meiji period in showing preferences for bird’s-eye views and emphasizing symbols of modernity such as railroads and electricity. The depiction of villa clusters is a remarkable feature of the three maps. However, rather than encouraging actual visits to the villas, the mapmakers – the local shop owners and administrators – achieved in producing these maps as souvenirs and creating a public desire for the lifestyle of high society.

PICTORIAL MAPS AND THE RISE OF MODERN RESORT IN ŌISO IN THE MID-MEIJI PERIOD

This study explores three pictorial maps produced in the mid-Meiji period (1868–1912) featuring Ōiso and the relationship between these maps and the rise of Ōiso as a modern resort. Ōiso was a town located on the highway Tōkaidō connecting Edo (or Tokyo after 1868) and Kyoto. It became a modern seaside resort after the late 1880s. Previous studies on visual and cartographic representations of towns and cities in Japan, for example, Kindai nihon no shikakuteki keiken [Visual experiences of modern Japan] (Nakanishi and Sekido 2008), have already narrowed the analytical focus and shifted away from the metropolises to provincial cities and hot spring towns. However, some questions, such as the social functions of these materials, remain unexplored. This study analyzes three maps and argues that these maps highlight Ōiso as an attractive place, particularly by featuring its villa residents from the high society. Visually, they resemble the conventional meisho zue [pictures of famous places] developed in the Edo period (1603-1867) and share with other city/town maps produced in the Meiji period in showing preferences for bird’s-eye views and emphasizing symbols of modernity such as railroads and electricity. The depiction of villa clusters is a remarkable feature of the three maps. However, rather than encouraging actual visits to the villas, the mapmakers – the local shop owners and administrators – achieved in producing these maps as souvenirs and creating a public desire for the lifestyle of high society.

Crustal thickness variations beneath Egypt through gravity inversion and forward modeling: linking surface thermal anomalies and Moho topography

This study aims to quantify the topography of the Moho boundary, the lower crust and uppermost mantle contact of Egypt, in order to estimate the crustal thickness variation and its link to the distribution of thermal anomalies under Egypt. This is accomplished by modeling satellite gravity, supported by the passive seismic constraints throughout Egypt. However, when estimating the thickness of the crust in Egypt using just seismic data, substantial uncertainty and deviation are produced due to the sparsely dispersed stations. Integrating seismic and gravity data minimizes uncertainty and improves estimate accuracy. The investigation is broken down into four stages, the first involving utilizing the Sentinel-3B satellite to create land surface temperature maps. The subsequent steps consist of gravity and seismic data adjustments, inversion and forward modeling. We used seismically restricted nonlinear inversion to look at Goco06s satellite gravity data to model the Moho’s topographic surface. The data gathered from deep seismic refraction and receiver functions adjusted the analyzed data. The inversion process relies on the adapted Bott's approach and Tikhonov regularization, using the assumption of the sphericity of the Earth planet. Reference values for depth of Moho and density contrast were set at 35 km and 500 kg/m3, respectively. The average statistical difference for Moho depth between gravity-based model and seismic data is − 0.10 km. Through forward gravity modeling, five gravity profiles were chosen and interpreted in 2.5D models. The results indicated that the Moho depth in the south varies from 35 to 39 km and decreases in the north and the Mediterranean. In upper Egypt, the highest Moho depth is 39 km. The depth varies beneath the Sinai Peninsula as it is about 35 km in its south, reaches 30 km in the northern portion, and ranges along the Red Sea’s Rift Margin from 29 to 32 km. Moreover, the final model shows the relation between Moho coincides with the surface temperature anomalies approved by satellite images and hot springs. The model reveals a correlation between Moho discontinuity and surface temperature anomalies, revealing the highest geothermal potential in a rectangular area in central Egypt, between latitudes 25°N and 30°N, based on satellite imagery and hot springs distribution.

Contrasting temperature and light sensitivities of spring leaf phenology between understory shrubs and canopy trees: Implications for phenological escape

Spring leaf phenology influences plant fitness and is highly sensitive to environmental changes. The spring phenological escape hypothesis posits that deciduous understory plants generally leaf out earlier than canopy trees to access a period of high light before the canopy closes. However, plants in different forest layers may respond differently to climate warming, which could lead to phenological mismatch between the understory and canopy species. Therefore, exploring the phenological sensitivities of plants from different forest layers is crucial for anticipating the effects of climate-driven phenological shifts. However, these types of studies are still scarce. Here, we conducted a twig experiment in climate chambers for eight tree species and seven shrub species growing in subtropical deciduous forests in the Shennongjia Mountains, central China. Specifically, we set up three treatments (control, warming, and shading) for five weeks to test the responses of the timing of bud burst and leaf unfolding, and the duration of bud development to different temperatures and light intensities. For shrubs, bud burst and leaf unfolding occurred earlier and the duration of bud development was shorter than these of trees. For both shrubs and trees, warming significantly advanced the timing of leaf unfolding and shortened the duration of bud development. Shading significantly delayed the timing of bud burst for both shrubs and trees. Shading also delayed the timing of leaf unfolding and lengthened the duration of bud development for trees, but did not significantly influence the two phenological metrics for shrubs. Tree phenology, as measured by all three metrics, was more sensitive to temperature than was shrub phenology. The timing of bud burst of shrubs was slightly more sensitive to light than that of trees. Our results indicate that shrubs leaf out earlier than trees in the same forest, which allows understory species to take advantage of the high-light resources before canopy closure. However, in our study, trees were more responsive to warming temperatures, suggesting that spring warming could advance canopy closure relative to shrub leaf phenology, potentially resulting in phenological mismatch between understory shrubs and canopy trees.

Revitalizing your sleep: the impact of daytime physical activity and balneotherapy during a spa stay

BackgroundIn modern society, achieving high-quality sleep is increasingly challenging. We conducted a study to explore the potential benefits of daytime physical activity and balneotherapy, including mud application and thermal-water bathing, on sleep quality.MethodsTo assess daytime physical activity and sleep parameters, we actigraphically monitored 127 healthy participants (34.6% male, average age 64.61 ± 0.89 years) during a one-week stay at a spa resort, where they received mud application and thermal-water bathings.ResultsParticipants were divided into three groups based on the timing of mud application. Those receiving mud application before 8:30 a.m. tended to have shorter sleep durations compared to those with later application, especially if it occurred before 7:45 a.m. However, mud application did not significantly affect sleep quality. Three-way ANCOVA revealed a significant effect of daytime physical activity on delta Sleep Efficiency, but post-hoc tests were insignificant. Furthermore, analyzing the duration of daily thermal-water bathings, individuals bathing for over 75 min per day experienced a noteworthy improvement in sleep quality, particularly in terms of delta Sleep Efficiency (2.15 ± 0.9% vs. −0.34 ± 0.31%, p = 0.007).ConclusionOur findings suggest that extended thermal-water bathing may enhance objective aspects of sleep quality. Since balneotherapy is mainly prescribed for individuals with musculoskeletal pathologies or psychological disorders, these findings may encourage doctors to recommend bathing in thermal water also to healthy subjects. Future researchers need to investigate the role of daytime physical activity in depth.

Investigation of optical, mechanical, thermal, wettability, and antibacterial activity of polyvinyl alcohol mixed with clay nanoparticles

In this research, polyvinyl alcohol (PVA) was mixed with clay nanoparticles with weight ratios of 1, 3, or 5 wt% to form PVA/clay composites using the solvent casting method for food packaging uses. Chemical bonds and function groups were identified using Fourier transform infrared spectroscopy, while mechanical parameters e.g. tensile strength (Tsr), elongation (Eb), and Young modulus (Ym) of the synthesized PVA/clay film were examined. Other characteristics were studied and discussed such as water uptake (swelling and porosity), contact angle, optical qualities (transmission, brightness), barrier properties i.e. water vapor transfer rate, and antimicrobial performance. The addition of clay nanoparticles raised Ym from 1.3 MPa to 2.9 MPa, while decreasing Tsr and Eb from 77 MPa and 3.8 % to 59 MPa and 3.6 %, respectively. Also, incorporating clay nanoparticles reduces water absorption, moisture level, transmission, and brightnesswhile improving the thermal conductivity and water vaportransport rates of PVA. Furthermore, the incorporation of clay nanoparticles improves thermal, mechanical, optical, and antibacterial performance, which could be beneficial for food packaging applications.

Hydrogeologic and hydrochemical inputs to emerging wetlands on the shores of the receding Salton Sea, California

AbstractThe Salton Sea has experienced significant recession over the past two decades due to changes in the diversion of Colorado River water to the Salton Trough for agricultural irrigation. As a result, wetlands have emerged in some exposed playa areas along the Salton Sea, primarily in regions with extensive agricultural return flows and agricultural drainage. One notable wetland system, known as the Bombay Beach Wetlands, has formed on the north shore of the Salton Sea, in an area devoid of agriculture. In many other areas with limited or no agriculture, wetlands have failed to develop, leaving exposed playa surfaces as the Salton Sea recedes. These dry playa surfaces pose a significant threat to the health of local residents due to the presence of toxins contained in windblown dust associated with playa deposits. In this study, stable water isotope data, combined with other hydrological information, led to identification of two potential water sources for the Bombay Beach Wetlands. The first possibility proposes that thermal artesian waters alone contribute to the wetlands' water source, while the second hypothesis involves a combination of drainage from Salton Sea bank storage water mixing with the thermal artesian water. The thermal artesian water discharges into drainage channels that flow towards the Bombay Beach Wetlands, initially devoid of possible groundwater baseflow until reaching the wetlands. Studies were subsequently done along the full reach of the drainage channels receiving thermal artesian water. Dissolved solids content, P and N nutrients, arsenic, and stable water isotopes were tested synoptically along the drainage channels. Channel investigations led to the development of a novel model of salinization, which is linked to channel discharge, channel morphometrics, and channel incision.

Deciphering the geochemical influences on bacterial diversity and communities among two Algerian hot springs.

Northeastern Algeria boasts numerous hot springs, yet these hydrothermal sites remain largely unexplored for their microbial ecology. The present study explores the bacterial abundance and diversity within two distinct Algerian hot springs (Hammam Saïda and Hammam Debagh) and investigates the link between the prevailing bacteria with geochemical parameters. High-throughput 16S rRNA gene sequencing of water and sediment samples revealed a bacterial dominance of 99.85-91.16% compared to Archaea (0.14-0.66%) in both springs. Interestingly, Saïda hot spring, characterized by higher temperatures and sodium content, harbored a community dominated by Pseudomonadota (51.13%), whereas Debagh, a Ca-Cl-SO4 type spring, was primarily populated by Bacillota with 55.33%. Bacteroidota displayed even distribution across both sites. Additional phyla, including Chloroflexota, Deinococcota, Cyanobacteriota, and Chlorobiota, were also present. Environmental factors, particularly temperature, sodium, potassium, and alkalinity, significantly influenced bacterial diversity and composition. These findings shed light on the interplay between distinct microbial communities and their associated geochemical properties, providing valuable insights for future research on biogeochemical processes in these unique ecosystems driven by distinct environmental conditions, including potential applications in bioremediation and enzyme discovery.

Mineral and Geochemical Features of Zeolite-Silica Deposits of the Pauzhetka Geothermal Field (Southern Kamchatka)

On the Pauzhetka geothermal field the mineral deposits which are formed, when dumping thermal water of separators of wells, are allocated. Compositions, structure and geochemical properties of this precipitation on pro-deleting and in vertical slits of “raincoats” are studied. It is established that they are put X-ray amorphous mordenite – opal mixes (in the beginning dumping of thermal waters), further precipitation becomes completely siliceous. The zeolitic component of mineral deposits defines their high sorption properties in the relation of Au, Ag, Hg, As, Rb, Sr, Ba, Cs, etc. elements; in a mordenitovy matrix sulfides of iron, silver, copper are formed. It is shown that the mineral deposits which are formed on the day surface of the Pauzhetka geothermal field are the indicator of alkaline mineral- and the ore-forming processes on the lower horizons of the Pauzhetka hydrothermal system.

Soil Study and Identification of Plant Species Growing Near Two Thermal Springs (Ain El Haouamed and Ain Hamra) in the Eastern Region of Morocco

Soil Study and Identification of Plant Species Growing Near Two Thermal Springs (Ain El Haouamed and Ain Hamra) in the Eastern Region of Morocco

Assessing the Helium Potential of Variscan Batholiths: Insight From Corsica Island

AbstractMost of the current helium (He) reserves originate from fortuitous discoveries, mainly made during oil and gas exploration in sedimentary basins. As helium generation depends on U and Th α‐decay, old geological provinces gather key ingredients for high He accumulation. However, numerous He‐rich springs have also been documented in much younger rocks, such as Variscan granites (320–250 Ma). These latter discoveries question the current exploration guidelines and require revisiting some of the longstanding paradigms. Here, is investigated He migration along a major fault rooted in the Corso‐Sardinian batholith (France). Two thermal springs, Caldanelle and Guagno‐Les‐Bains, show significant outgassing activities of crustal sourced He with concentrations up to 1.45 vol% and flow rates of 110 m3 STP 4He/year. Besides He, the gas phase is dominated by N2 (≈98 vol%) and minor CH4. Based on a survey employing multidisciplinary methodologies, it is revealed that (a) Variscan rocks represent efficient 4He source rocks, (b) the main source of He comes from the underlying Eo‐Variscan basement, (c) A deeply rooted fault and dense fractures networks drain the He, (d) the helium loss is limited, (e) faults and fractures may act as partial traps, and finally (f) the presence of an efficient trap could promote a He‐rich reservoir with high flux but low reserves. In that sense, young post‐orogenic granites represent promising helium plays. The geological context in which Caldanelle and Guagno‐Les‐Bains are embedded is ubiquitous in European Variscan batholiths. This case study is therefore intended to serve as a guide for helium exploration and to provide insights into helium behavior within a Variscan geological context.

Underwater additive manufacturing of 10CrNi3MoV high-strength low-alloy steel by wire-feed laser melting deposition: Effect of microstructure evolution on mechanical properties

The underwater 10CrNi3MoV high-strength low-alloy steel thin-walled part with forming quality up to in-air laser deposition quality was successfully manufactured for the first time. The influencing mechanisms of complicated thermal history and water environment on microstructure evolution and mechanical properties of thin-walled part were researched. Due to austenitization and interlocking effect, the microstructure in the bottom, middle and top (below the 56th layer) areas of underwater sample and the middle area of in-air sample were composed of fine grain ferrite and granular bainite. With the increase of building height, the heat accumulation effect of underwater sample enhanced, resulting in small grain size (GS), high dislocation density, strong solution strengthening effect and low maximum texture strength at the bottom area, while the high proportion of high-angle grain boundaries (HAGBs) at the top area. These resulted in the greatest tensile strength (714 MPa) and microhardness (232 HV) at the bottom area and the highest elongation (11%) at the top area. Due to the cooling effect of water environment, the proportion of HAGBs reduced and there were oxides in fracture. As a result, the horizontal elongation of underwater sample was about 90.9% of in-air sample. Additionally, the GS reduced, and the dislocation density and solution strengthening effect increased, so the microhardness of underwater sample was slightly higher than that of in-air sample. However, due to some microscopic defects, the horizontal and vertical tensile strength of underwater sample were about 97.6% and 90.7% of in-air sample.

Investigation of optical, mechanical, thermal, wettability, and antibacterial activity of polyvinyl alcohol mixed with clay nanoparticles

In this research, polyvinyl alcohol (PVA) was mixed with clay nanoparticles with weight ratios of 1, 3, or 5 wt% to form PVA/clay composites using the solvent casting method for food packaging uses. Chemical bonds and function groups were identified using Fourier transform infrared spectroscopy, while mechanical parameters e.g. tensile strength (Tsr), elongation (Eb), and Young modulus (Ym) of the synthesized PVA/clay film were examined. Other characteristics were studied and discussed such as water uptake (swelling and porosity), contact angle, optical qualities (transmission, brightness), barrier properties i.e. water vapor transfer rate, and antimicrobial performance. The addition of clay nanoparticles raised Ym from 1.3 MPa to 2.9 MPa, while decreasing Tsr and Eb from 77 MPa and 3.8 % to 59 MPa and 3.6 %, respectively. Also, incorporating clay nanoparticles reduces water absorption, moisture level, transmission, and brightnesswhile improving the thermal conductivity and water vaportransport rates of PVA. Furthermore, the incorporation of clay nanoparticles improves thermal, mechanical, optical, and antibacterial performance, which could be beneficial for food packaging applications.

The Evolution of Small Town Spa Resorts in the Global South: The Historical Pathway of Montagu, South Africa

An important resource for small town tourism is maximising the local advantage of natural mineral springs. Only a small international literature exists on the evolution of spa resorts with scant writings for the Global South. For small town South Africa the histories of spa tourism mostly are unrecorded. This article addresses this knowledge gap by investigating the historical development of one spa tourism resort, namely Montagu in the Western Cape. Archival and documentary sources are utilised to analyse the tourism development of this small town from its formal establishment in the early 1850s to the closing apartheid years during the late 1980s. It is shown that Montagu’s rise was part of the wider growth of South Africa as a health destination which was anchored upon its assets of climate and mineral springs. The thermal springs of Montagu put the town on the tourist map resulting in its declaration as a health resort and emergence as a popular holiday destination. By the time of the apartheid period Montagu was becoming a more leisure-tourism dominated and a less health focussed destination.

Significance and Applications of the Thermo-Acidophilic Microalga Galdieria sulphuraria (Cyanidiophytina, Rhodophyta)

Galdieria sulphuraria is a thermo-acidophilic microalga belonging to the Cyanidiophyceae (Rhodophyta) class. It thrives in extreme environments, such as geothermal sulphuric springs, with low pH, high temperatures, and high salinity. This microalga utilises various growth modes, including autotrophic, heterotrophic, and mixotrophic, enabling it to exploit diverse organic carbon sources. Remarkably, G. sulphuraria survives and produces a range of bioactive compounds in these harsh conditions. Moreover, it plays a significant role in environmental remediation by removing nutrients, pathogens, and heavy metals from various wastewater sources. It can also recover rare earth elements from mining wastewater and electronic waste. This review article explores the diverse applications and significant contributions of G. sulphuraria.