Hydrothermal Features Research Articles

On the hydrothermal features of MHD nanofluid flow over a differently shaped thin needle influenced by Hall current with nonlinear thermal radiation

PurposeThe investigation has appraised the problem of an incompressible laminar steady magnetohydrodynamic (MHD) nanofluid stream over three distinct slendering thin isothermal needles of paraboloid, cylindrical and cone shapes. Water as a base liquid is assumed in this flow model. The influences of the Hall current and variable sorts of magnetic forces have enriched our investigation. Energy and concentration expressions consist of thermophoresis and Brownian migration phenomena. The analysis of thermal and mass slips of the presumed model has also been performed.Design/methodology/approachA relevant transformation is implemented for the alteration of the leading partial differential equations (PDEs) to the equations with nonlinear ordinary form. Due to the strong nonlinearity of the foremost equations, the problem is solved numerically by embedding the well-known RK-4 shooting practice. The software MAPLE 2017 has been exploited in reckoning the entire computation. To enunciate the investigated upshots, some graphical diagrams have been regarded here. According to technological interest, we measured the engineering quantities like the Sherwood number, the coefficient of drag friction and the Nusselt number in tabular customs.FindingsThe obtained consequences support that Hall current intensifies fluid movement when the needle is in a cone shape, while the superior velocity is noticed for cylindrical-shaped needles. The transference of heat responds inversely along with the growths of thermal and mass slip factors.Originality/valueNo work has been performed on the flow model of radiated nanofluid over a variable-shaped thin needle under Hall current, the variable magnetic field and different slip factors.

Oligocene magmato-tectonic events influential in the development of Pb-Zn, Ag, and Au mineralization at the Plomosas deposit, southwestern Sierra Madre Occidental, Mexico

ABSTRACT The Plomosas deposit is the product of a sequence of overlapping events of Pb–Zn, Ag, and Au low sulfidation mineralization that occurred in Mexico’s southwestern Sierra Madre Occidental (SMO). Field observations, detailed petrography, and U–Pb age dating of the entire stratigraphic sequence were used to characterize the magmatic evolution of the district and to obtain new insights into the evolution of the SMO. The stratigraphy at Plomosas is distinct from other areas to the north as it lacks Jurassic marine units, Cretaceous continental volcanic successions as well as Cretaceous and Palaeocene batholiths. The local basement is composed of undeformed Late Jurassic volcaniclastic units and coeval felsic intrusions. Early to late Oligocene silicic ignimbrites, intermediate lava flows, and occasional basaltic flows unconformably overlie the Jurassic basement. Several Oligocene intermediate to felsic porphyry bodies and rhyolitic domes crosscut the stratigraphy. The upper volcanic sequence is separated into two packages by an angular unconformity. Mineralization produced an early Pb–Zn-mineralized hydrothermal fault breccia, followed by Cu–Ag veins and late Au veins. The Pb–Zn mineralized breccia is hosted by ~30 Ma Oligocene volcanic units that form the basal sequence. The Cu–Ag and Au-rich veins overlap and crosscut the early hydrothermal features and cut the late Oligocene volcanic cover that unconformably overlie the basal sequence. Our results highlight the importance of episodes of Oligocene magmatism to the genesis of mineralization in the southwestern SMO specifically through a genetic link between Pb–Zn veins and intermediate Oligocene intrusive bodies, and of Ag and Au veins with late Oligocene volcanism.

Modern analogs for ammonia flux from terrestrial hydrothermal features to the Archean atmosphere

The isotopic composition of nitrogen in the rock record provides valuable evidence of reactive nitrogen sources and processing on early Earth, but the wide range of δ15N values (− 10.2 to + 50.4‰) leads to ambiguity in defining the early Precambrian nitrogen cycle. The high δ15N values have been explained by large fractionation associated with the onset of nitrification and/or fractionation produced by ammonia-ammonium equilibrium and water–air flux in alkaline paleolakes. Previous flux sensitivity studies in modern water bodies report alkaline pH is not a prerequisite and temperature can be the dominate parameter driving water–air flux. Here, I use the chemical and physical components of 1022 modern hydrothermal features to provide evidence that water–air NH3 flux produced a significant source of fixed nitrogen to early Earth’s atmosphere and biosphere. With regard to the modeled average NH3 flux (2.1 kg N m−2 year−1) and outlier removed average flux (1.2 kg N m−2 year−1), the Archean Earth’s surface would need to be 0.0092, and 0.017% terrestrial hydrothermal features, respectively, for the flux to match the annual amount of N produced by biogenic fixation on modern Earth. Water–air NH3 flux from terrestrial hydrothermal features may have played a significant role in supplying bioavailable nitrogen to early life.

Comparing microbial populations from diverse hydrothermal features in Yellowstone National Park: hot springs and mud volcanoes.

Geothermal features, such as hot springs and mud volcanoes, host diverse microbial life, including many extremophile organisms. The physicochemical parameters of the geothermal feature, such as temperature, pH, and heavy metal concentration, can influence the alpha and beta diversity of microbial life in these environments, as can spatiotemporal differences between sites and sampling. In this study, water and sediment samples were collected and analyzed from eight geothermal sites at Yellowstone National Park, including six hot springs, a mud volcano, and an acidic lake within the same week in July 2019, and these geothermal sites varied greatly in their temperature, pH, and chemical composition. All samples were processed and analyzed with the same methodology and taxonomic profiles and alpha and beta diversity metrics determined with 16S rRNA sequencing. These microbial diversity results were then analyzed with respect to pH, temperature, and chemical composition of the geothermal features. Results indicated that predominant microbial species varied greatly depending on the physicochemical composition of the geothermal site, with decreases in pH and increases in dissolved heavy metals in the water corresponding to decreases in alpha diversity, especially in the sediment samples. Similarly, sites with acidic pH values had more similar microbial populations (beta diversity) to one another than to relatively neutral or alkaline pH geothermal sites. This study suggests that pH and/or heavy metal concentration is a more important driver for microbial diversity and population profile than the temperature for these sites and is also the first reported microbial diversity study for multiple geothermal sites in Yellowstone National Park, including the relatively new mud volcano Black Dragon's Caldron, which erupted in 1948.

Geology and Structure of the Río Blanco Cu-Mo Porphyry Deposit, Central Chile

Abstract The Río Blanco-Los Bronces deposit is the largest Cu-Mo porphyry deposit in the world in terms of contained Cu metal. It is the product of protracted superposed magmatic and hydrothermal activity associated with multiple intrusive and brecciation events, with simultaneous regional uplift, erosion and unroofing, and decompression. Magmatism resulted in three major mineralization-alteration stages. The premineralization stage occurred during the emplacement of the San Francisco batholith, resulting in late magmatic and early hydrothermal events. The synmineralization stage corresponds to the main hydrothermal events associated with the Río Blanco-Los Bronces porphyry and breccia complexes, which were related to three intrusion phases, widespread brecciation, and an epithermal-style advanced argillic alteration. Late-stage magmatism, followed by hydrothermal activity, was associated with the emplacement of subvolcanic rhyolite complexes and late-stage porphyry intrusions. The synmineralization intrusions are associated with high-grade breccia bodies that have well-defined alteration-zonation patterns. Compilation and analysis of the historical Río Blanco structural data sets from the different mines, tunnels, and pits have allowed the assignment of all mapped structures to four hierarchical orders based on their continuity, crosscutting relationships, and infill compositions. The larger structures (orders 0 and 1) have along-strike continuity, correlate between drifts and/or mine levels, whereas smaller structures (orders 2 and 3) were grouped according to their dimensions and distributions within the larger-order structure-defined panels. All orders 0 and 1 structures were modeled in three dimensions, while orders 2 and 3 were in two dimensions. The structures mapped at Río Blanco have an intimate relationship with the pre- to the late-stage geologic evolution of magmatism and mineralization. The regional-and to a lesser extent district-scale structural evolution was related to premineralization basin-opening and subsequent tectonic inversion, whereas at the camp scale, syn- to late mineralization intrusions and related hydrothermal features were superimposed on this inherited structural architecture.

A CFD examination of free convective flow of a non-Newtonian viscoplastic fluid using ANSYS Fluent

In this work, a laminar steady-state investigation of free convection in a square cavity with differential heated side walls is examined. The cavity is immersed with a viscoplastic liquid the Bingham prototype. The horizontal walls are assumed as adiabatic and the vertical wall has two spatial differing sinusoidal temperature profiles with diverse phases and amplitudes. The hydro-thermal features are systematically analyzed via a broad choice of Rayleigh numbers Ra (103-106), Bingham numbers Bn, Prandtl numbers Pr (0.1, 1, 10), amplitude ratio ε (0–––1), phase difference ϕ (0-π) and flow index n (0.3–2). The governing equations are treated computationally utilizing a commercial computational simulation code CFD: FLUENT. It has been observed that average Nusselt numbers grow with growing Rayleigh numbers and drop with increasing Bingham quantity Bn, since heat transition occurs primarily due to thermic conductivity. In general, a higher Rayleigh number promotes convection and increases heat transfer efficiency, leading toa higher Nusselt number, whereas a higher Bingham number, indicating a higher degree of viscous or yield-stress behavior, may inhibit convection and decrease heat transfer efficiency, which ended in a lower Nusselt number. These connections frequently appear in heat transport and fluid dynamics simulations. The rise in the phase difference suggests an upsurge in heat transference, as the impact of the phase shift on the Nusselt is perpetually enhanced due to the amount of Rayleigh boosts for all phase differences. Heat transition rate forϕ=πis boosted because of the values. Moreover, when the amplitude ratio goes up, so does heat transfer. The gap between average Nusselt and Rayleigh amounts rose as the Rayleigh rose. The thermal flow rate is bigger in ε=1 than in the other cases. The rise in phase difference suggests a rise in heat transference, as this effect of phase shift on Nusselt continues to be enhanced due to the amount of Rayleigh boosts for all phase differences. Heat transition rate is enhanced forϕ=πbased on the values. Plus, when the amplitude ratio grows, so does heat transmission. The rate of heat transport for ε=1 is larger than in the other cases.

Origin and mineralization processes of REE during magmatic-hydrothermal evolution: Insights from in-situ geochemistry of calcite from the Weishan REE deposit, eastern North China Craton

The Weishan REE deposit, hosting more than one million tons of light REE oxides (LREE2O3), is one of the largest LREE deposits in China. It has been considered to be a carbonatite-related REE deposit, but whether carbonatites occurred or not is still controversial, leading to the confusions of how the LREE originated and mineralized. Here, we conducted in-situ elemental and Sr-Nd isotopic analyses on different stages of calcite from the Weishan REE deposit, combined with petrographic and bulk C-O isotopic studies, with the aim to unravel the origin and mineralization processes of REE. Four stages of calcite (Cal-1, Cal-2, Cal-3 and Cal-4) were identified, of which the Cal-1 typically coexists with K-feldspar and quartz while the Cal-2 and Cal-3 coexist with sulfates and REE minerals (e.g., bastnäsite and parisite), respectively. The Cal-4 occurs in the post-ore veinlets and coexists with sulfides. The Cal-1 is characterized by exsolution of carbocernaite along its cleavage planes with highest Na, K, Sr, Ba and LREE contents. The other stages of calcite show continuous decrease of the above elements. Combined with petrographic features and elemental discrimination diagrams, it is concluded that the Cal-1 is magmatic while the others are hydrothermal. These calcites thus indicate a continuous magmatic-hydrothermal evolution. The four stages of calcite show similar isotopic compositions, which are consistent with those of the alkaline silicate rocks in the ore district, suggesting an uniform source or magma chamber for their derivation. Considering the magmatic features of Cal-1, it is inferred that carbonate melts coupled with abundant alkaline fluids were exsolved from the alkaline magmas. Alkalis (e. g., K and Na) were enriched in the magmatic-hydrothermal system with potassic metasomatism being more prevalent, which might play an important role in REE exsolution and transportation. Focused REE deposition occurred shortly after massive deposition of sulfates, indicating that REE-sulfate complexes might be the dominant transporting ligands of REE. The deposition of REE was mainly induced by fluid boiling, as indicated by the boiling/unmixing features of fluid inclusions. The Sr-Nd isotopic compositions of ores and associated alkaline rocks show affinities to the enriched lithospheric mantle (EM) beneath the study region, but are more depleted. Because subduction of the Paleo-Pacific oceanic plate beneath the eastern Asian occurred since the Jurassic, it is inferred that CO2- and REE-rich melts/fluids released from the subducted oceanic slab metasomatized the EM, leading to a REE-rich carbonated mantle. Rollback of the subducted slab occurred during the early Cretaceous, resulting in partial melting of the EM and thus generating the CO2- and REE-rich alkaline magmas. This deposit shows significant hydrothermal features with poorly-developed carbonatites, distinct from the typical carbonatite-related REE deposits in the other places. The REE mineralization is thus considered to be basically controlled by the alkaline magmas rather than the carbonatites.

Entropy Generation in a Magnetohydrodynamic Hybrid Nanofluid Flow over a Nonlinear Permeable Surface with Velocity Slip Effect

The current study is designed to model the hydrothermal feature of a hybrid nano liquid slip flows over a permeable expanding/contracting surface with entropy generation. The model incorporates Cu-Al2O3 nanoparticles with water as the host liquid to simulate the flow. Additional impacts incorporated into the novelty of the model are viscous dissipation and Joule heating. The model is transformed appropriately to its dimensionless form using similarity quantities and the solution is numerically obtained using the spectral quasi-linearization method (SQLM). The impact of pertinent factors on the flow characteristics is communicated through graphs for the hybrid nano-suspension to discuss the hydrothermal variations. The friction factor and the rate of heat transport are also discussed with sensible judgment through tables. To ensure the code validity, a comparison with earlier studies is conducted and excellent consensus is accomplished. The result explored that diminution in the irreversibility ratio is witnessed for rising magnetic field strength along the free stream, distance away from the permeable surface as the heat dissipation to the surrounding decelerates. Also, the augmented nonlinearity parameter intensified the heat transfer rate for about 2.79% of the hybrid nano-suspension.

Thumping Cycle Variations of Doublet Pool in Yellowstone National Park, USA

AbstractDoublet Pool is an active hydrothermal feature in Yellowstone National Park, USA. Approximately every half hour, it thumps for about 10 min due to bubbles collapsing at the base of the pool. To understand its thermodynamics and sensitivity to external factors, we performed a recurring multiple‐year passive seismic experiment. By linking recorded hydrothermal tremor with active thumping, we determine the onset and end of thumping, and the duration of silence between each thumping cycle. The silence interval decreased from around 30 min before November 2016 to around 13 min in September 2018. This change followed unusual thermal activity on the surrounding Geyser Hill. On a shorter time scale, wind‐driven evaporative cooling can lengthen the pre‐thumping silence interval. Based on energy conservation, we determine the heating rate and heat needed to initiate thumping to be 3–7 MW and ∼6 GJ, respectively.

Geological structure and hydrothermal alteration mapping for mineral deposit prospectivity using airborne geomagnetic and multispectral data in Zuru Province, northwestern Nigeria

Spatial associations involving alterations and structures are common with orogenic systems, however porphyry deposits are not spatially well defined especially due to overprinting of alteration types. In this study, multi-disciplinary geoscience information from digitally-enhanced airborne data over Zuru province, northwest Nigeria were analyzed and synthesized to unravel uncertainties about the spatial alignment of both structural and hydrothermal features in porphyry prospects. Processed aeromagnetic data showed the tectonic regime and the associated lineaments of the Anka province which presumably controlled the mineral localization and distribution in the province. The multispectral interpretations of the hydrothermal expressions illustrated the major alteration zones such as potassic, phyllic, argillic and propylitic domains. The delineated surface structures in the province are regarded as the main reason for alteration zone formation in the country rocks where the traversed lineaments in the existing rocks symbolizes a plumbing system responsible for hydrothermal fluid flow, and hence mineral bearing alteration zones were developed. Spatial analysis involving contrast estimation was performed to quantify the spatial relationship between known mineral deposits and geologic features that can influence mineralization. Propylitic alterations are noticeable as prominent alteration zones with mineral deposits, whereas the phyllic alterations presented the lowest possibility of mineral occurrence. Further spatial analysis involving statistical contrast estimation between mineral deposits and a deep-seated regional structure showed maximum spatial relationship around the 35-km buffer zone. The mineral deposits exhibit spatial association with the trans-current lineament assertive of a strong influence of the geologic structure on mineral deposition and regional pluton emplacement.

Analysis of the 2021 Milford, Utah earthquake swarm: Enhanced earthquake catalog and migration patterns

An earthquake swarm occurred in Spring 2021 in south-central Utah near the town of Milford. The University of Utah Seismograph Stations located 125 earthquakes between March 19 and May 10 with magnitudes ranging from 0.5 to 3.2. We implement a matched-filter technique in order to identify additional earthquakes that went undetected during the routine network location. The 125 network-located earthquakes are used as templates and are cross-correlated with continuous data for the dates Feb 17—June 10. This time period corresponds to approximately 1 month before the earthquake swarm began through 1 month after it ended. For the matched-filter analysis, we rely heavily on station FOR1, which is located within 5 km of most template events. Four other stations within 20–30 km of most template events provide a supplement to the closest station. The matched-filter implementation results in the detection of over 600 earthquakes in addition to the original 125 catalog events. This is one of the largest swarms ever recorded in Utah, and no previous large swarms have been recorded in this location. We use HypoDD to obtain relative double-difference locations of the catalog events. Both routine locations and HypoDD relocations of the catalog events suggest a fault dipping west beneath the mountain range, opposite of typical Basin and Range normal faults that dip beneath alluvial valleys. Moment tensors for the largest five events show normal faulting consistent with the west-dipping fault seen in the seismicity. Hydrothermal features in the area, including a geothermal power plant, suggest that fluids may be a contributing factor to the earthquake swarm triggering. We examine the role of fluids by exploring bounds on diffusion parameters and investigating spatial migration characteristics of the swarm seismicity. We conclude that this swarm is the result of heterogenous stress conditions in a prefractured region.

Time‐Lapse Geophysical Investigation of Geyser Dynamics at Spouter Geyser, Yellowstone National Park: Geyser Dynamics II

AbstractGeysers are unique hydrothermal features, requiring specific geometry, fluid, and vapor input, and heat to produce eruptions. In a geyser eruption, the decompression of superheated hydrothermal fluids results in a conversion of thermal to kinetic energy. Recent studies conclude that a laterally offset cavity structure (bubble trap) plays an integral role in the geyser eruption process. In this second study of Spouter Geyser, Yellowstone National Park (YNP), we build on the geyser structure developed in the first publication and explore how structural components, such as the bubble trap, control eruption dynamics. We utilize time‐lapse electrical resistivity tomography (ERT) and transient electromagnetics (TEM) geophysical methods to track changes in the saturation of conductive hydrothermal fluid and resistive vapor through the eruption cycle. Additionally, we use pressure‐temperature transducer data to measure eruption and recharge durations over the past 23 years at Spouter Geyser, identifying long‐period trends in geyser behavior. The geophysics results support the bubble trap model, capturing an increase in resistivity in the bubble trap structure during the recharge phase interpreted as a vapor saturation increase. The TEM also captures a resistivity increase in the 20–30 m depth interval during the eruption phase, interpreted as a vapor‐dominated “flash eruption zone” where the superheated hydrothermal fluids flash into steam and drive fluid out of this zone during the eruption. From the temperature time‐series detailing 23 years of eruption and recharge durations, we find that eruption durations have remained constant at ∼2 hr while recharge durations have decreased linearly at 6.6 min/year.

Comparative heat transfer analysis on Fe3O4–H2O and Fe3O4–Cu–H2O flow inside a tilted square porous cavity with shape effects

The objective of this paper is to investigate the energy transmission rate's features of the natural convective radiative Fe3O4–H2O nanofluid and Fe3O4–Cu–H2O hybrid nanofluid flow in a tilted square porous cavity under the influence of heat source/sink. The marker and cell method is adopted to solve the system of partial differential equations. The outcomes explore that in the existence of heat source, by augmenting the volume fraction of spherical-, cylindrical-, column-, and lamina-shaped nanoparticles from 1% to 5% in water, the average heat transfer rate is boosted by 6.07%, 8.36%, 9.89%, and 14.95%, respectively. In the existence of heat sink, the increment is noticed as 2.67%, 3.68%, 4.37%, and 6.64%, respectively. Therefore, the shape of the nanoparticles considerably varies the heat transfer rate. In the existence of heat source, by magnifying the volume fraction of spherical-, cylindrical-, column-, and lamina-shaped Fe3O4–Cu nanoparticles from 1% to 5% in water, the mean heat transfer rate is magnified by 7.23%, 11.03%, 14.15%, and 31.36%, respectively. In the existence of heat sink, the magnification is detected as 3.18%, 4.87%, 6.27%, and 14.09%, respectively. This result confirms that the proper combination of nanoparticles considerably enhances the heat transfer characteristics of base fluids. The findings of this study may be helpful for a better understanding of hydrothermal features of thermal systems such as heat exchangers, helical heat sinks, solar collectors, periodic pin-fins, mini shell and tube heat exchangers, plate evaporators, photothermal cancer treatment, and microvascular vessels using various unitary and hybrid nanofluids.

Comparison of hydrothermal fluids and fields of the northern Okataina Volcanic Centre: Fifty years ago to present time

Hydrothermal features in the Okataina Volcanic Centre, North Island, New Zealand, are found predominantly along the northern and southern boundaries of the centre. Very little work has been done studying the northern fluids, although yearly samples are collected from a handful of locations for monitoring purposes. In this study, we examine fluids from the Tikitere and Rotoma-Tikorangi geothermal fields, which are located along the northern OVC boundary near Lakes Rotoiti, Rotoehu and Rotoma and compare them to published, historical data from the region and more recent monitoring data where available. Samples taken from the lakeshores of Lake Rotoiti and at Waitangi Soda Springs indicate bicarbonate-chloride rich fluids that show minimal changes since 1970. Alkali geothermometer temperatures estimating reservoir temperatures range from around 220 at Waitangi Soda Springs to 290 °C at Manupirua Spring and show great consistency over the years despite their equilibrium immaturity. In contrast, slightly further south and higher in elevation, the Hells Gate Thermal Park, a popular tourist location, has a wider range of hotter geothermometer temperatures and features acid-sulfate fluids. There have been noticeable changes here since 1970, with new pools formed, and an evident enrichment in stable water isotopes, indicating greater water rock interactions and greater evaporation have occurred over time. Overall, hydrothermal fluids from the northern Okataina Volcanic Centre show good stability and low eruption risk at present time.

Comparative analysis of the hydrothermal features of TiO2 water and ethylene glycol-based nanofluid transportation over a radially stretchable disk

This study focuses on the comprehensive analysis of the thermal characterization of an electrically conducting nanofluid flow containing TiO2 nanoparticles dissolved in two different common liquids (H2O and C2H6O2) and contained within a continuously extending disk. The heat and concentration formulation are modified by incorporating the standard interpretations of the Joule heating, energy source, dissipation, and modified activation energy with binary chemical reactions. The Darcy–Forchheimer addition is used to highlight the significance of porous media. The Brownian dispersion’s effects are clearly discernible in the current investigation. Furthermore, as a novelty, special thermophysical models of viscosity and thermal conductivity are included. The obtained differential formulations are tackled through the analytical procedure HAM. The veracity of the finding is verified through a numerical scheme (ND-solve technique). Using several graphs and charts, the perception trends of model factors are evaluated. The influence of and are estimated based on flow characteristics. The curve pattern for both nanofluids is declined by the increasing magnitude of and while thermal profile. The drag force and heat transmission rate are shown to optimize with as well as in the pictorial simulations produced from the existing model. The can also be strengthened by the presence of a high degree The outcomes are validated by previous studies and a good degree of consistency is revealed.

Violent Groundwater Eruption Triggered by a Distant Earthquake

AbstractIt is now well established that earthquakes cause various hydrogeological responses at distances thousands of kilometers from the epicenter. What remains unexplained is the large amplitude and intensity of some responses. Following the 2004 Mw 9.1 Sumatra earthquake, groundwater 3,200 km from the epicenter erupted violently from a well and formed a water fountain reaching a height exceeding 60 m. We model the relevant processes by combining tidal analysis of groundwater level with numerical simulations using a two‐dimensional finite‐element model. We suggest that the eruption resulted from a combination of factors, including a rapid increase of crustal permeability and runaway CO2 exsolution and bubble nucleation induced by the passage of seismic waves. Our results may have implications for some engineering applications such as oil production and CO2 sequestration, and the eruption of hydrothermal features such as geysers.

Geochemistry and fluxes of gases from hydrothermal features at Newberry Volcano, Oregon, USA

We present the chemical and isotopic compositions of gases and fluxes of CO2 from the hydrothermal features of Newberry Volcano, a large composite volcano located in Oregon's Cascade Range with a summit caldera that hosts two lakes, Paulina and East Lakes. Gas samples were collected from 1982 to 2021 from Paulina Hot Springs (PHS) on the shore of Paulina Lake, East Lake Hot Springs (ELHS) on the shore of East Lake, and Obsidian Flow Gas Seep (OFGS), an area of diffuse gas emissions. Surveys of CO2 flux were conducted in 2020 at OFGS (1400 m2) and East Lake (4.1 km2). Gases from all three sites were CO2-rich (≥79 mol% in dry gas) but showed considerable compositional variability over time due to interaction with ground and surface water. An increase in H2S concentrations and decline in CO2/H2S ratios in ELHS gases coincided with a drop in East Lake water level from 1999 to 2021. ELHS and OFGS gases were high in CH4 relative to PHS and the δ13C of CH4 values for ELHS gases (−72.2 and − 63.6 ‰) reflected a predominantly biogenic origin. The dominant source of N2 and Ar in PHS, ELHS, and OFGS samples was likely groundwater. Helium isotopic ratios (6.47 to 8.02 Rc/Ra) support a persistent source of magmatic He beneath Newberry caldera and consistently high values measured at OFGS and PHS relative to ELHS suggest distinct fluid flow paths from depth to the surface features. The δ13C of CO2 and CO2/3He values (−8.9 to −5.35 ‰ and 1.3 × 109 to 4.6 × 1010, respectively) measured in gases reflect contributions of CO2 from both mantle and crustal sources. Measured CO2 fluxes at OFGS and East Lake ranged from 1 to 8808 and < 1 to 364 g m−2 d−1, respectively. A CO2 emission rate of 0.5 t d−1 was calculated for OFGS. The CO2 emission rate estimated for East Lake was 30 t d−1 and when compared to prior estimates, reflects steady-state lake degassing. An enhanced geochemical monitoring plan, including annual sampling of gases at ELHS, OFGS, and PHS for geochemical analysis, installation of a continuous lake-level monitoring station at East Lake, and annual CO2 flux surveys at OFGS, would provide valuable background data and insights into any precursor volcanic activity. Integrating geochemical data with data from the real-time seismic and GPS network at Newberry Volcano could better resolve and interpret potential changes in its magma-hydrothermal system.

Hydrothermal features of the magnetite nanoparticles on natural convection flow through a square conduit by using the finite element method

Ferrofluids are made through the suspension of magnetic nanoparticles which are commonly used for the treatment of hyperthermia, malignant tumor treatment, magnetic cell separation, etc. These nanoparticles provide satisfactory results for the heat transport phenomena. Motivated by the applications of these nanoparticles, this study is performed for water-based nanofluid with a different type of magnetic nanoparticles for renewable energy and the development of the advanced cooling process of the radiator. Further, this study also talks about the impact of magnetized nanoparticles on natural convection flow occupied in a square cavity. The nanosized magnetic particles are mixed up in water to make a more convective flow. In this computational study, the momentum equation is updated with magnetohydrodynamics terms. The mathematical problem is achieved in the form of nonlinear complex partial differential equations which are simulated by using the renowned Galerkin finite element technique. The numerical code is validated with the previous study on the natural convection flow of viscous fluid in a square cavity and the verification procedure verified the good accuracy of the applied developed numerical code. The impact of the Hartmann number, Rayleigh number and the volume friction coefficient is discussed through contours and graphs. It is observed that nanofluids have more capacity to store energy as compared to regular fluids due to superior thermal transport properties. Moreover, the cobalt oxide (Co3[Formula: see text] nanoparticles provide a greater heat transfer rate due to greater thermal conductivity as compared to other nanoparticles cobalt ferrite (CoFe2[Formula: see text], magnetite (Fe3[Formula: see text] and manganese–zinc–ferrite (Mn–Zn–Fe2[Formula: see text]. The heat transfer rate is increased by 30% for cobalt oxide, 18% for magnetite, 15% for manganese–zinc–ferrite and 12% for cobalt ferrite, respectively. Hence, the cobalt oxide nanoparticles which have a greater heat transfer rate can contribute to solar energy engineering and the advanced cooling process of the radiator.

Impact of viscous dissipation and coriolis effects in heat and mass transfer analysis of the 3D non-Newtonian fluid flow

The hydro-thermal features of 3D (3-dimensional) nonlinear Carreau fluid motion over a paraboloid surface of revolution are examined. The impacts of thermal radiation and mass transfer are considered during the fluid motion. The flow is modeled by a set of nonlinear coupled partial differential equations (PDEs) satisfying certain associated boundary conditions. Appropriate transformations are used to convert the coupled system of PDEs to ODEs. The resultant coupled ODEs system is solved analytically by using the well developed analytical procedure of Homotopy Analysis Technique (HAM). The influence of relevant parameters are investigated on the state functions of the Carreau fluid MHD motion by depicting 2D graphs. It has been found that the increasing thickness of paraboloid surface of revolution augments the fluid velocity and shear stress components, whereas drops the gradient in the velocity distribution. The enhancing Grashof number increases the fluid velocity components as well as its gradients. The increasing magnetic field strength retards the fluid migration, and therefore drops the velocity gradients. The increasing rotation parameter augments the horizontal component of velocity and reduces the velocity vertical component. The fluid temperature enhances with the increasing strength of radiation source, internal heat source, and reflection parameters. The enhancing chemical reaction parameter values drop the fluid concentration. The convective heat energy transport increases with the enhancing Brownian motion, while the convective mass transfer rises with the increasing radiation source strength. The results obtained are compared with a numerical technique by graphs and tables, where the accuracy and effectiveness of HAM is proved The agreement of the obtained results and the published research validates the exactness of the applied analytical technique.

Geologic controls on hydrothermal groundwater mixing in Yellowstone National Park

The hydrothermal system in Yellowstone National Park, arguably the most well-studied hydrothermal system in the world, offers a unique opportunity to study the complex interaction between deep, superheated, anoxic hydrothermal fluids and meteorically-sourced oxidizing waters in the near subsurface. Past research has established that hydrothermal waters originate from a hot source gas infused deep aquifer below the surface, and that mixing with modern meteoric water occurs to various degrees. However, many of mechanisms driving flow and mixing are still poorly understood. This study aims to geophysically image the conduits sustaining hot springs, and the below ground features that drive mixing of deeply-sourced hydrothermal water and meteorically-derived groundwater. We focus on the large-scale spatial relationships (10s of meters) between ascending hydrothermal fluids and geologic units, the sources of shallow hydrothermal water, and most importantly whether hydrologic mixing occurs prior to discharge at either the various hydrothermal features or “cold” springs. Our results reveal subsurface permeable zones in rhyolites that determine large-scale vertical flow paths of hydrothermal fluids. We compare the geophysical results and spatial relations of the hot springs to Cl− and SO42− concentrations in Yellowstone waters. From our interpretations, we propose an updated conceptual model showing the interactions between the shallow meteoric recharge system and deeper originated hydrothermal system that may inform interpretations of hydrothermal systems in Yellowstone and elsewhere.