Spring Source Research Articles

Water Sources of Lake Bottom Springs in Lake Kawaguchi, Northern Foot of Mount Fuji, Japan

Water Sources of Lake Bottom Springs in Lake Kawaguchi, Northern Foot of Mount Fuji, Japan

A Recently Discovered Spring Source of the Aqua Traiana at Vicarello, Lazio

We report on an important spring source among the headwaters of the Aqua Traiana, the aqueduct introduced by the emperor Trajan to Rome in 109 CE. Located at Vicarello, adjacent to the celebrated t...

Contrasting volcano spacing along SW Japan arc caused by difference in age of subducting lithosphere

The SW Japan arc built by subduction of the Philippine Sea (PHS) plate exhibits uneven distribution of volcanoes: thirteen Quaternary composite volcanoes form in the western half of this arc, Kyushu Island, while only two in the eastern half, Chugoku district. Reconstruction of the PHS plate back to 14 Ma, together with examinations based on thermal structure models constrained by high-density heat flow data and a petrological model for dehydration reactions suggest that fluids are discharged actively at depths of 90–100 km in the hydrous layer at the top of the old (> 50 Ma), hence, cold lithosphere sinking beneath Kyushu Island. In contrast, the young (15–25 Ma) oceanic crust downgoing beneath Chugoku district releases fluids largely at shallower depths, i.e. beneath the non-volcanic forearc, to cause characteristic tectonic tremors and low-frequency earthquakes (LFEs) and be the source of specific brine springs. Much larger amounts of fluids supplied to the magma source region in the western SW Japan arc could build more densely-distributed volcanoes.

Energy performance and economic feasibility of hot spring-based district heating system – A case study

As a versatile platform for integrating renewable energies, District Heating systems (DHSs) offer a pragmatic approach toward an environmentally benign and sustainable future. This paper puts forward the feasibility evaluation of using geothermal hot spring source Heat pumps (HPs) for district heating of a village situated in the north-west of Iran, with a cold mountain climate. Solar collectors are also integrated into the DHS as a supplementary heat source. To this aim, three different renewable-energy-based district heating scenarios, viz. a Ground-Source-HP-based (GSHP), a combined GSHP-flat-plate-solar-collector (GSHP-SFPC), and a combined GSHP-linear-parabolic-solar-collector (GSHP-SLPC), along with a fossil-fuel-based (FFB) district heating scenario are evaluated. In order to make an impartial comparison, all scenarios are first dynamically optimized based on their Life Cycle Cost (LCC). Then the annual energetic, exergetic, economic, and environmental performance of the studied scenarios is evaluated and discussed. The obtained results demonstrated that the GSHP-SLPC system has the lowest LCC; however, it has the highest initial investment cost. Moreover, while the initial investment cost of the GSHP-SFPC is 19% lower than the GSHP-SLPC, its LCC is only 4.4% higher. Also, the total contribution of renewable energy sources is 54.1%, 60.2%, and 67.9% for the GSHP, GSHP-SFPC, and GSHP-SLPC systems, respectively.

Groundwater Recharge Potential Mapping in Far Western Middle Mountain of Nepal: A GIS-based Approach

The larger population in the middle mountain region of Nepal is dependenton spring for domestic water use. Availability and flow regularity of springs rely on groundwater recharge (GWR) potential which is attributed to various natural and human factors. The present study is an attempt to explore the GWR potential using GIS and Remote sensing (RS) method in two watersheds of the far western middle mountains of Nepal. Spatial analysis is carried out using a weighted overlay analysis of six factors namely, slope, lithology, lineament, drainage density, rainfall, and land cover/ land use. The result shows that only 16 percent of the total watershed area is under a very high recharge potential zone while 31 percent area falls under very low recharge potential. It is found that the distribution of existing spring sources is random concerning GWR potential. Water stress in Rel Gad watershed is evident which accentuates the proper management of recharge areas. The study concludes that the GIS RS tool is useful in identifying recharge potential zones. It aids to better planning for increasing recharge potential. Proper management of recharge potential area and spring water sources direct the future water availability to fulfill the increasing water need of the communities.

Hot spring frogs (Buergeria japonica) prefer cooler water to hot water.

“Hot spring frog” is an informal name used for the Japanese stream tree frog (Buergeria japonica), which is widely distributed in Taiwan and the Ryukyu Archipelago in Japan. Some populations of the species are known to inhabit hot springs. However, water temperature can be extremely high around the sources of hot springs. Thus, it is questionable whether B. japonica selectively inhabits such dangerous environments. To address this question, we conducted a series of observations of water temperature preferences of a hot spring population of B. japonica in Kuchinoshima Island in Japan: (a) a field observation of tadpole density in water pools of different temperatures, (b) a field observation of water temperatures where adult males appear for breeding, and (c) an indoor observation of water temperatures selected by adult females for oviposition. As a result, tadpoles showed a higher density in cooler water. Adult males avoided water pools hotter than 37°C, and adult females selected cooler pools for oviposition. Camera records also showed that adult individuals tend to appear around cooler pools. Thus, we did not find any support for the hypothesis that hot spring frogs prefer hot water. Conversely, they apparently tended to prefer cooler water if it was available. Water temperatures around the sources of the hot spring exceed thermal tolerances of the species and could be a strong selective pressure on the population. Thus, the ability to sense and avoid lethal temperatures may be a key ecological and physiological characteristic for the species that inhabit hot springs.

Types and Sources of Drinking Water: A Case Study of Lungleng Village, Mizoram

Water supply is one of the most important problem faced by the rural people in Mizoram. Lungleng village is also no exception in this regard. Everyday water is needed for drinking, cooking and other domestic purpose is used to collect from the nearby streams and other water sources. Sources of water supply in Lungleng village can be broadly classified into three types, namely; public-piped water points, village spring sources and rain water harvesting. Among the water sources as mentioned above; public-piped water points and village spring sources constitute major sources of water supply in rural areas. Inspite of several efforts done by the Government for providing adequate water supply like construction of impounding reservoir and pumping of water from nearby streams and rivers till today Lunleng village faces acute and perpetual water supply. Especially during summer months when the water sources become dry men and women would queue for several hours to collect a few buckets water. The present paper is an attempt to study the details of water sources and associate problems in Lungleng village.

Ciliate diversity in cold water spring sources in Iceland

Cold groundwater springs at the edges of lava fields along the volcanic active zone in Iceland are an interesting habitat, presenting an ecotone between groundwater, surface water and the terrestrial ecosystems. They are categorized as fennoscandian mineral-rich springs according to the European Nature Information System (EUNIS) classification (C2.111 European Environmental Agency) and have a high conservation value. They are also an island-like phenomena in the landscape and, together with the stable chemical and physical properties of the groundwater, make excellent study sites for testing questions regarding community assembly theory. To explore the biota of these systems, we applied environmental metabarcoding to assess ciliate diversity in this habitat. DNA was extracted and metabarcoding based on the 18S rRNA gene was conducted for (1) water samples and (2) glass beads as support for biomass development. Alpha diversity for ciliate communities in the spring sources increased with temperature, and limnocrene springs had fewer, more abundant taxa than rheocrene springs. Differences were observed between the water samples and the glass bead samples, mainly in terms of abundance. When considering only the water samples, no variation was found among spring source communities, indicating that stochastic processes such as dispersal and ecological drift might be important in shaping the community composition.

Seasonal Variation of Water-soluble Ions in PM2.5 in Xi'an

To explore the seasonal variations and sources of water-soluble ions, PM2.5 samples were collected from 2017 to 2018. Water-soluble ions including SO42-, NO3-, Cl-, F-, Na+, Mg2+, NH4+, K+, and Ca2+ were determined via ion chromatography. Furthermore, the existing form of NH4+, nitrogen oxidation rate (NOR), sulfur oxidation rate (SOR), and [NO3-]/[SO42-] ratio were explored. The results showed that dust, coal combustion, biomass burning, and secondary aerosols were the dominant contributors to water-soluble ions. Ca2+, SO42-, NH4+, and NO3- were the main water-soluble ions in PM2.5 in Xi'an. Correlation analysis results showed that NH4+ could not completely neutralize SO42- in spring; unneutralized SO42- could be mainly combined with K+ and Ca2+. NH4+ mainly existed in the form of ① NH4HSO4 and (NH4)2SO4 in summer; ② NH4HSO4 and NH4NO3 in autumn; and ③ (NH4)2SO4 and NH4NO3 in winter. The yearly mean values of SOR and NOR were 0.35 and 0.16, respectively, indicating a high secondary aerosol transformation rate during the study period. The [NO3-]/[SO42-] ratio showed Xi'an was mainly affected by stationary sources in spring and summer, while the contribution of mobile sources in autumn and winter was greater than stationary sources.

Characteristics of microbial activity in atmospheric aerosols and its relationship to chemical composition of PM2.5 in Xi'an, China

Microbial activity levels in atmospheric aerosols can affect human health, and ecosystem and atmospheric processes. However, information on the influence of microbial activity in atmospheric aerosols remains very limited. In this study, the characteristics of microbial activity in atmospheric aerosols in Xi'an, China, were determined using the fluorescein diacetate hydrolysis method. The influences of meteorological factors, height and water-soluble inorganic ions on microbial activity were examined. The results indicate that the levels of the atmospheric inorganic ions increased as the air quality index (AQI) increased. The microbial activity and concentration of PM2.5 were significantly positively correlated during sampling period (p < 0.05). Notably, microbial activity levels in PM2.5 and PM10 both increased with the AQI and decreased from ground level to 228 m. Additionally, higher microbial activity levels were detected during floating dust events and lower levels were found during periods of rainfall. Among the nine inorganic ions, microbial activity was significantly positively correlated with Na+, Mg2+ and Ca2+ (p < 0.05). Correlation results indicate that microbial activity was greatly influenced by soil source in spring and summer. The present results improve our understanding of the correlations between airborne microbes and atmospheric chemical composition.

Terrain genetic unit for spring-based regional development in mountains in Indonesia

This research was carried out in the Mount Mandalawangi region of West Java Province. The research objective is to explore the potential sources of springs in supporting the development of the region so as to encourage the economic potential of the community. The methodology used was geological mapping, spatial mapping, mapping of socio-economic conditions, mapping of water demand levels, which were evaluated using the Terrain Genetic Unit method. The area around Mount Mandalawangi is a relatively fertile area has ±36 points of springs, the discharge ranges from 0.00003 m3/sec-0.587 ltr/sec. The dominant lithology is the Mandalawangi (Qmm) Mountain consisting of glass tuffs containing pumice, and lava composed of pyroxene andesite to basalt. The results of the study using the Terrain Genetics Unit method there are 3 zones that have the potential to develop springs based on the region, Andesite Plateau, Corrugated Hills of Lapili Volcano and Corrugated Hills of Tuff Breccia Interference. The analysis is that regional development can be planned to the maximum by prioritizing the source of spring with a note that there needs to be an arrangement for the source of existing springs.

Functional Factors of Biomass Burning Contribution to Spring Aerosol Composition in a Megacity: Combined FTIR-PCA Analyses

Whether the spring season brings additional pollution to the urban environment remains questionable for a megacity. Aerosol sampling and characterization was performed in the urban background of the Moscow megacity in spring 2017, in a period of a significant impact of mass advection from surrounding fire regions. Parametrization of Angstrom absorption exponent (AAE) on low and high values provides periods dominated by fossil fuel (FF) combustion and affected by biomass burning (BB), respectively. The period identification is supported by air mass transportation from the south of Russia through the regions where a number of fires were observed. Functionalities in entire aerosol composition, assigned to classes of organic, ionic compounds, and dust, are inferred by diffusion refection infrared Fourier transmission (FTIR) spectroscopy. Functional markers of urban transport emissions relate to modern engine technology and driving cycles. Regional BB functionalities indicate the fire impacts to the spring aerosol composition. The development of the advanced source apportionment for a megacity is performed by means of combined ambient FTIR data and statistical PCA analysis. PCA of FTIR spectral data differentiate daily aerosol chemistry by low and high AAE values, related to FF- and BB-affected spectral features. PC loadings of 58%, 21%, and 11% of variability reveal the functional factors of transport, biomass burning, biogenic, dust, and secondary aerosol spring source impacts.

First direct observation of sea salt aerosol production from blowing snow above sea ice

Abstract. Two consecutive cruises in the Weddell Sea, Antarctica, in winter 2013 provided the first direct observations of sea salt aerosol (SSA) production from blowing snow above sea ice, thereby validating a model hypothesis to account for winter time SSA maxima in the Antarctic. Blowing or drifting snow often leads to increases in SSA during and after storms. For the first time it is shown that snow on sea ice is depleted in sulfate relative to sodium with respect to seawater. Similar depletion in bulk aerosol sized ∼0.3–6 µm above sea ice provided the evidence that most sea salt originated from snow on sea ice and not the open ocean or leads, e.g. &gt;90 % during the 8 June to 12 August 2013 period. A temporally very close association of snow and aerosol particle dynamics together with the long distance to the nearest open ocean further supports SSA originating from a local source. A mass budget estimate shows that snow on sea ice contains even at low salinity (&lt;0.1 psu) more than enough sea salt to account for observed increases in atmospheric SSA during storms if released by sublimation. Furthermore, snow on sea ice and blowing snow showed no or small depletion of bromide relative to sodium with respect to seawater, whereas aerosol was enriched at 2 m and depleted at 29 m, suggesting that significant bromine loss takes place in the aerosol phase further aloft and that SSA from blowing snow is a source of atmospheric reactive bromine, an important ozone sink, even during winter darkness. The relative increase in aerosol concentrations with wind speed was much larger above sea ice than above the open ocean, highlighting the importance of a sea ice source in winter and early spring for the aerosol burden above sea ice. Comparison of absolute increases in aerosol concentrations during storms suggests that to a first order corresponding aerosol fluxes above sea ice can rival those above the open ocean depending on particle size. Evaluation of the current model for SSA production from blowing snow showed that the parameterizations used can generally be applied to snow on sea ice. Snow salinity, a sensitive model parameter, depends to a first order on snowpack depth and therefore was higher above first-year sea ice (FYI) than above multi-year sea ice (MYI). Shifts in the ratio of FYI and MYI over time are therefore expected to change the seasonal SSA source flux and contribute to the variability of SSA in ice cores, which represents both an opportunity and a challenge for the quantitative interpretation of sea salt in ice cores as a proxy for sea ice.

Isotopic Study of Springs Near Haditha Dam Western Iraq

Stable isotopic technique and hydrochemistry was used in studying the water resources interaction of near Haditha Reservoir area, western Iraq. Throughout the study area, 14 groundwater samples (Bashina, Zwachi springs and Wells), 8 surface water samples from the study area, and 7 spring samples were analyzed for 2H and 18O stable isotopes and hydrochemical analysis. In this study, the temperature, altitude and continental effects on the isotopic composition of rain water in Iraq were studied. The climate of the study area is classified as semi-arid to arid region. The results show a variation in the isotopic values of Haditha reservoir and Euphrates river. This variation is due to the effect of the low surface area and the low velocity of water of Haditha Reservoir on the amount of evaporation, compared with the high velocity and the large surface area of Euphrates river. There was a variation in the isotopic values between Bishina and Zwachi springs, due to two factors that appear to modify the isotopic signatures of the springs, namely the lack of hydraulic connection between the springs of Bishina and Zwachi, meaning that they recharge from different sources. The changes in oxygen isotope composition of the groundwater between a deep reservoir and the springs (Bishina) may be caused by the dilution with near surface waters (Haditha reservoir) with different oxygen isotope compositions. The variation in the isotopic content in the studied area indicated that there are various origins of springs recharge and a different interactions of the multiple sources of springs with the mutli-depths of springs water.

Carbon Oxidation State in Microbial Polar Lipids Suggests Adaptation to Hot Spring Temperature and Redox Gradients.

The influence of oxidation-reduction (redox) potential on the expression of biomolecules is a topic of ongoing exploration in geobiology. In this study, we investigate the novel possibility that structures and compositions of lipids produced by microbial communities are sensitive to environmental redox conditions. We extracted lipids from microbial biomass collected along the thermal and redox gradients of four alkaline hot springs in Yellowstone National Park (YNP) and investigated patterns in the average oxidation state of carbon (ZC), a metric calculated from the chemical formulae of lipid structures. Carbon in intact polar lipids (IPLs) and their alkyl chains becomes more oxidized (higher ZC) with increasing distance from each of the four hot spring sources. This coincides with decreased water temperature and increased concentrations of oxidized inorganic solutes, such as dissolved oxygen, sulfate, and nitrate. Carbon in IPLs is most reduced (lowest ZC) in the hot, reduced conditions upstream, with abundance-weighted ZC values between −1.68 and −1.56. These values increase gradually downstream to around −1.36 to −1.33 in microbial communities living between 29.0 and 38.1°C. This near-linear increase in ZC can be attributed to a shift from ether-linked to ester-linked alkyl chains, a decrease in average aliphatic carbons per chain (nC), an increase in average degree of unsaturation per chain (nUnsat), and increased cyclization in tetraether lipids. The ZC of lipid headgroups and backbones did not change significantly downstream. Expression of lipids with relatively reduced carbon under reduced conditions and oxidized lipids under oxidized conditions may indicate microbial adaptation across environmental gradients in temperature and electron donor/acceptor supply.

Hydrochemistry of tropical springs using multivariate statistical analysis in Ithikkara and Kallada river basins, Kerala, India

Spring waters are the most important natural resource used for drinking by many people around the world, especially in arid and semi-arid areas. This resource cannot be optimally used and sustained, unless the quality of groundwater is assessed. The main objective of this study is to understand the quality and hydrochemistry of spring water sources of two important river basins of Southern Western Ghats—the Ithikkara and the Kallada river basins draining Kollam district of Southern Kerala as an example. Water Quality Index (WQI) values are used to assess the drinking suitability of spring water samples. Multivariate statistical approach (factor analysis and principal component analysis) allow driving hidden information from the data set about their possible influences of the environment on water quality. Multivariate analysis was performed on matrix of hydro-geochemical data. To study the influences of the environment on water quality, multivariate statistical approach is applied. A total of 57 samples were collected and analyzed for major cations and anions for pre-monsoon, monsoon and post-monsoon seasons of 2011–2012 periods from lowland and highland regions of the study area. The results of the WQI values show that majority of the samples fall in Excellent to Good category rendering these water samples suitable for drinking purposes. From the statistical analysis, it is inferred that in catchments rich with pyrite in rocks and clays, drainage of sulphuric acid may significantly contribute to acidity. The negative loading in pH and DO is due to anaerobic conditions in the spring source from the loading of high-dissolved organic matter, which results in the formation of ammonia and organic acids leading to a decrease in pH. The positive loading of SiO2 reflects the dissolution of silica minerals and high temperature. The evaluation of the saturation index of the water samples in highland regions indicted that water was oversaturated with respect to iron minerals and undersaturated with fluorite minerals. The chemistry of the spring waters favors kaolinization and subsequent leaching of mobile elements like alkali and alkaline earth elements. The study is helpful in understanding the relationship between individual ions and for the classification of groundwater types.

First measurement of human exposure to current use pesticides (CUPs) in the atmosphere of central Chile: The case study of Mauco cohort

Chile is a leading agricultural producer and thus consumer of insecticides, herbicides, and fungicides. In Molina, Central Chile, a prospective cohort has been established for studying the incidence and risk factors of chronic diseases in the adult population. Our goals were to measure airborne current use pesticides (CUPs), assess their spatial distribution and potential sources, and estimate health risks for the population in Molina.CUPs were measured using passive air samplers (PAS), deployed on six sites from October 2015 to August 2016. Thirty-eight pesticides were analyzed using high performance liquid chromatography (HPLC), but only nine of them were detected. Chlorpyrifos (CPF) was detected with air concentrations ranging from 444 to 14 624 (pg m−3). Diazinon, atrazine, dimethoate, metolachlor, simazine, terbuthylazine and tebuconazole were also detected; only pendimethalin had concentrations as high as those of CPF, with a maximum of 14 927 (pg m−3).Backward wind trajectories were used to estimate locations of potential sources contributing to airborne CUPs concentrations. Most of the exposure to CUPs was associated with local sources, while regional sources southern/eastern/western of Molina appear to contribute as secondary sources (soil evaporation followed by atmospheric transport) in spring and summer seasons.A health risk assessment using US-EPA's methodology was carried out for inhalation exposure of detected pesticides. None of the measured CUPs were associated with a hazard quotient (HQ) greater than 1, indicating no significant risk due to inhalation of pesticides in Molina's population with the exception of the group of children below 12 years old. However, further investigations are needed to evaluate others CUPs exposure route such as food consumption and dermal exposure to improve our health risk estimations.

Changes of groundwater flow systems after the 2016 Mw 7.0 Kumamoto earthquake deduced by stable isotopic and CFC-12 compositions of natural springs

Large earthquakes change the hydrogeological properties of aquifer systems, such as permeability, and cause changes that impact groundwater flow. To understand these changes in mountain aquifer systems, we analyzed stable isotopic ratios of water molecular (δD and δ18O) of H2O and chlorofluorocarbons (CFCs) concentrations of natural spring waters and compared these values between before (2009) and after (2017) the 2016 Kumamoto crustal earthquake sequence in Kumamoto-Aso area, southern Japan. Stable isotope ratios were used to identify the spring source characteristics that reflected recharge elevations, whereas CFC age tracers were applied to evaluate the contribution of earthquake-induced additional waters from different pathways (shorter or longer) and/or CFC-enriched (contaminated) surface waters. In general, spring waters after the earthquake became more depleted in water isotopic compositions than those before the earthquake, suggesting an increased contribution of waters recharged from higher elevations across the area. In addition, changes observed in CFC-12 concentrations were classified into several increasing/decreasing patterns defined by the contribution of additional waters from different flow paths, such as older groundwater with longer flow paths, younger groundwater from shorter flow paths, and CFC-enriched (contaminated) water released from shallow aquifers and soils. These isotopic and chemical features, when combined with previously documented seismotectonic surface rupture distributions, demonstrated the occurrence of coseismic mountain water release due to enhanced permeability. These findings enabled us to document how groundwater flow changes in mountain aquifers. Although CFC age markers have rarely been applied as a tool to investigate coseismic hydrological changes, our study exemplifies their usefulness—in combination with stable isotope ratios—in such investigations.

Net heterotrophy and low carbon dioxide emissions from biological processes in the Yellow River Estuary, China

Although estimates of total CO2 emissions from global estuaries are gradually decreasing, current numbers are based on limited data and the impacts of anthropogenic and seasonal disturbances have not been studied extensively. Our study estimates annual and seasonal CO2 fluxes in China’s Yellow River Estuary (YRE) which incorporated spatiotemporal variations and the effects of water and sediment regulation (WSR). Aquatic metabolism was estimated using Odum’s open water dissolved oxygen methods and used to represent the production and assimilation of CO2. Net ecosystem production (NEP) was used to represent the CO2 flux from biological activities and estimate the major CO2 emitters in the YRE.According to our measurements, the annual CO2 release was 6.14 ± 33.63 mol C m−2 yr−1 from 2009 to 2013 and the annual CO2 efflux from the 1521.3 km2 of estuarine surface area was 0.11 ± 0.61 Tg C yr−1 in the YRE. High CO2 emissions in autumn were balanced by high CO2 sequestration in summer, leading to a lower than expected annual net CO2 efflux. The system is an atmospheric CO2 source in spring and winter, near neutral in early summer, a large sink in late summer after WSR, and finally a large atmospheric CO2 source in autumn. Discharge events and seasonality jointly affect estuarine CO2 flux. High CO2 sequestration in summer is due mainly to a combination of high water temperature, chlorophyll a levels, dissolved inorganic carbon, and solar radiation and low turbidity, discharge, and chemical oxygen demand (COD) after WSR. WSR supports the high gross primary productivity rate which exceeds the increase in ecosystem respiration.Although the YRE, as a whole, is a source of atmospheric CO2, the amount of CO2 released is lower than the average estuarine value of mid-latitude regions. Our findings therefore suggest that global CO2 release from estuarine systems is overestimated if spatiotemporal variations and the effects of anthropogenic disturbance are excluded. The NEP method is effective for estimating the CO2 flux, especially in estuaries where CO2 variation is mainly due to biological processes.

Analysis of a Tropical Warm Spring Microbiota Using 16S rRNA Metabarcoding

The Ikogosi Warm Spring is a unique ecological niche in Western Nigeria with an average temperature and pH of 38°C and 5.8 respectively. It mixes with an adjacent cold spring (28°C & pH 7.6), about 100 meters from source, yielding a confluence body of water of 32°C and pH 7.7. To explore the bacterial community structure of this uncommon environment and to scan for potentially useful bacteria, metagenomes extracted directly from five samples (source and mid-point of warm spring; source and midpoint of cold spring, and the confluence) were analyzed. Using the MiSeq Illumina next generation sequencing protocols, the V3-V4 region of the 16S rRNA gene pool was sequenced and analyzed by QIIME (Quantitative Insights into Microbial Ecology) and R software. At least 11% (47,446) of all the sequences were unknown to any of the databases employed. Bacterial diversity and abundance at the source of both springs were extremely low, accounting for less than 0.07% of the total sequence reads at the confluence, 100 m downstream. In contrast to the highly diversified mesophilic confluence community where 21 different phyla were identified, only 4 and 5 phyla were recovered from the source-point of the warm spring and cold spring respectively. The most prevalent phyla in all samples were members of the versatile Proteobacteria (35% - 50% relative abundance), and the hardy Firmicutes (33% - 40%). Operational taxonomic units (OTUs) obtained from all the samples averaged at 1414. Temperature and pH were equally significant predictors of genomic diversity and richness, with the warm and cold spring sources having less than 5 bacteria phyla. Exiguobacterium sp. (a potential plastic degrader) and other deep rooted bacteria were found in the warm spring while the cold spring outflow contained among others such as Rubrobacter sp. and Chloroflexi sp. (which is close to the phylogenetic root of the domain Bacteria). Many taxonomically unresolved sequences could indicate the presence of potentially novel bacteria in this unique body of water and underscores the need to systematically mine these rare genetic reservoirs for biotechnological applications. Moreover, such tropical hydrothermal ecosystems could contain some unknown primitive bacteria at the origins of life.