The crater lake of the active volcano "El Chichón" in Mexico, represents an ecosystem characterized by changing conditions of salinity, acidity, temperature, and the concentration of different heavy metals, posing significant challenges to the abundance and diversity of microorganisms. In this study, anaerobic mesophilic and hyperthermophilic prokaryotic microbiomes isolated from the volcano-lake were evaluated to elucidate the molecular and biochemical mechanisms involved in Cd2+ bioremoval. Cultures consumed actively carbohydrates, triacetylglycerol, acetate and methanol; the hyperthermophilic microbiome produced 50% more biomass than mesophiles at the end of the growth curve; however, the presence of Cd2+ stimulated the biomass and methane production in the mesophilic microbiome. The relative abundance of the 16S rRNA metabarcoding analysis showed dominance of Firmicutes and Euryarchaeota in both microbiomes. The constitutive synthesis of biofilm and the overproduction of polyphosphates and thiol group molecules were protection mechanisms against Cd2+ toxicity. Such mechanisms allowed 68-74% of Cd2+ bioremoval (biosorption plus accumulation) at concentrations up to 500 µM CdCl2. Data suggested that the prokaryotic microbiome isolated from the extreme environment of the "El Chichón" volcano is forming a complex metabolic resilient network involving methanogenesis with phosphate and sulfur metabolism that is capable of thriving under extreme conditions of pH, temperature, and the ability for the Cd2+ removal. This work provides for the first time, information on the mechanisms of tolerance to poly-extreme conditions; moreover, microbiomes studied here may be a promising strategy for biotechnological applications under extreme conditions.
Radon is a significant contributor to natural ionizing radiation and a relevant public health concern, particularly in volcanic environments. This study assesses the impact of the Tajogaite eruption on La Palma (Canary Islands), on indoor radon concentrations and associated radiation doses. A dosimetry survey was conducted using passive detectors and continuous radon monitoring, focusing on areas near the eruption center. Results show elevated radon concentrations near the volcano, decreasing exponentially with distance. However, the estimated dose in the most affected region was 0.3 mSv during the three-month eruption, well below critical health thresholds, indicating no significant public health risk to the exposed population. Temporal variations in radon were modulated by volcanic degassing and meteorological dynamics, including low wind speeds, directional shifts and height of the thermal inversion, which promoted near-surface gas accumulation. Principal Component Analysis and spectral coherence analyses confirmed the dual influence of subsurface and atmospheric processes, behaving differently during and after the eruption. Multifractal analysis of continuous radon recorded in the nearest monitoring station revealed a complex temporal behavior near the volcano, with long-range correlations and persistent behavior. Conversely, more distant monitoring stations exhibited lower complexity and stronger coupling with atmospheric variables. The estimated mean daily radon emission from the Tajogaite eruption (≈3.0 ± 1.4·107 Bq·m-2·day-1) was about 160 times higher than that reported for the quiescent Furnas volcano, and up to six orders of magnitude greater than radon emissions from natural soils worldwide. These findings highlight the importance of incorporating radon monitoring programs into volcanic hazard assessments.
Dual-atom catalysts (DACs) have demonstrated superior potential in the oxygen reduction reaction (ORR). However, the single-peak activity volcano derived from classical associative mechanism is contrast to the large-scale experimental data from the Digital Catalysis Platform (DigCat). Herein, we studied ORR over 200 DACs from thermodynamic and kinetic perspectives, and found that the dissociative mechanism is generally dominant for DACs. By integrating potential-related microkinetic modeling and machine learning (ML)-derived interpretable structural descriptors, we discovered a dual-Sabatier optima volcano map against ΔG(OH*) (or structural descriptors), which was rigorously validated against available experimental data. Dual-Sabatier optima stem from the rate-determining step of dissociative mechanism switching among three elementary reactions (O2 dissociation → 2OH protonation → OH protonation), which can be extended across DACs containing transition metal, metal-like, and non-metal elements as center atoms. It opens a brand-new perspective for rational design of DACs and atomically dispersed catalysts for other reactions beyond ORR, of which the dominant reaction mechanism may be different from single-atom catalysts (SACs) and lead to diverse activity volcano maps. Most importantly, this work illustrates that new phenomenon can be identified from "old experimental data" under a large data scale, with the help of theoretical simulations integrated with interpretable ML.
Magmatic systems can remain dormant for tens of thousands of years, creating a misleading perception of extinction that complicates hazard forecasting. To identify drivers of protracted quiescence, we integrate geochemical, isotopic, and zircon geochronological data comprising over 1250 crystallization ages from 31 eruptions at Methana, an active volcano near Athens, Greece. This record allows us to link eruptive activity, magma reservoir evolution, and mantle source variations over 700,000 years. Here, extended repose correlates with increased metasomatism of the mantle wedge by slab-derived components. The longest quiescence at Methana (>100,000 years) coincides with substantial magma production that was preferentially trapped in the crust. We attribute this trapping to the generation of superhydrous melts (>6 wt % H2O) from a highly metasomatized mantle. These volatile-rich magmas undergo water saturation and crystallize during ascent, preventing eruption. Such trapping mechanisms can grow large magma reservoirs and may enable transitions from small stratovolcanoes to highly hazardous, caldera-forming systems.
The Piparo Mud Volcano is a significant natural hazard in Trinidad and Tobago, highlighted by its violent 1997 eruption and subsequent heightened activity in 2019, 2024, and 2025. These events arise from overpressurized subsurface conditions that force fluidized mud and gas to the surface. Despite these ongoing risks, current monitoring frameworks remain surface-based and event-driven, offering limited insight into deeper structural and geophysical precursors of activity. To address this gap, this study applies gamma radiation monitoring to: (1) explore correlations between spatial radiation patterns and geomorphological features, (2) examine temporal variations, and (3) evaluate its potential to predict volcanic activity. Measurements were collected at 40 locations over a 29-month period at six intervals (0, 4, 11, 17, 23, 29), using a Geiger-Müller counter, positioned 1 m above ground level (GL) and 0.5 m below GL. The results revealed contrasting spatial patterns above and below GL, with elevated surface gamma radiation in fracture-dense southern and eastern crater areas, while below GL radiation peaked in opposing pressurized zones. Gamma radiation also varied systematically across three distinct phases: pre-activity (months 0-11), active (months 11-17), and post-activity (months 17-29). During pre-activity, gamma radiation increased above GL and declined below GL, then converged prior to an expulsion event in month 13, and diverged again during post-activity. These patterns demonstrate a clear link between gamma radiation fluctuations and mud volcanic activity, highlighting a novel method for early detection and improved hazard assessment.
The development of high-performance heavy-atom-free photosensitizers requires deep insight into their excited-state dynamics. We report a series of cyanine-based compounds functionalized at the C2 position that operate through spin-orbit charge transfer intersystem crossing (SOCT-ISC). A pronounced "volcano-type" relationship between photo-induced electron transfer (PeT) efficiency and singlet oxygen quantum yield was uncovered. Femtosecond transient spectroscopy and quantum chemical calculations reveal that this trend stems from a dynamic competition between S1 and T2 intersystem crossing from the charge-separated (CS) state and CS-state charge recombination via internal conversion. The CS-state energy serves as a key descriptor dictating this balance. By modulating the donor strength of the substituents, we optimized the CS-state energy and identified TCy-Pyr, a molecule near the volcano apex. TCy-Pyr exhibits outstanding photodynamic performance, with in vitro and in vivo anticancer efficacy surpassing conventional benchmarks. It also displays aggregation-induced targeting behavior, promoting selective tumor accumulation. This work elucidates the excited-state dynamics in SOCT-ISC systems and establishes a rational design strategy to overcome performance bottlenecks in photosensitizer development.
The purpose of this study is to investigate the potential use of rock samples collected from around an extinct volcano for radiation shielding applications. The eight rock samples examined in the study were collected from the Karacadağ Region of Şanlıurfa Province, Turkey. After the samples were collected, an elemental analysis was performed using X-ray Diffraction (XRD), and the elemental compositions were obtained via the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) method. Simulations were performed using MCNP-6.2, a radiation transport program, utilizing the elemental compositions obtained. The simulation results were compared with the data available in the XCOM database. Furthermore, the radiation shielding capabilities of the samples were evaluated by comparing the MCNP results with those of lead, which is widely used today. Unlike previous studies focusing on standard basaltic structures, this research uniquely evaluates the multi-layered volcanic lithology of the Karacadağ region. The results demonstrate that at low photon energies (up to 0.1 MeV), five of the eight samples (1, 2, 3, 5, 8) exhibited a higher linear attenuation coefficient (LAC) than 3 mm of lead, suggesting their potential as cost-effective and non-toxic alternatives for diagnostic X-ray shielding. These findings suggest that the use of these rocks could have positive impacts, both in reducing the cost of materials used for shielding and in making the cleared land suitable for agricultural use.
Microscopic minerals help Teresa Ubide understand volcanoes.
Deep marine sediments generate large amounts of methane, but most of this gas is consumed by the anaerobic oxidation of methane (AOM) mediated by microscopic consortia of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB). In this study, we investigated the AOM within a sulfate-methane transition zone (SMTZ) at a depth of ~9.6 m at the rim of the Ginsburg mud volcano in the Gulf of Cádiz. The SMTZ is supplied with sulfate from both overlying seawater and an underlying evaporitic deposit, and it coincides with a fracture zone that hosts a visible biofilm. Here, carbon dioxide shows the strongest 13C-depletion, indicating intense methane consumption. Metagenomic and lipid biomarker analysis of the biofilm revealed an exceptionally simple microbial community dominated by ANME-1b archaea (63%), which predominantly produce strongly 13C-depleted glycerol dialkyl glycerol tetraethers and, to a lesser extent, the less common macrocyclic archaeols. The putative partner bacterium Seep-SRB1c (Desulfobacterota) is less abundant (9%). Additionally, the biofilm contained five low-abundance heterotrophs that likely rely on biomass or metabolites released from the ANME-SRB consortium. Our study highlights the presence of active methanotrophic biofilms in subsurface sediments and suggests that these communities may play an overlooked role in mitigating seafloor methane emissions.
The rational design of cathode materials for aqueous zinc-ion batteries (AZIBs) has been guided by the principle that larger interlayer spacing facilitates greater Zn2+ storage. However, this geometric heuristic fails to explain the stark performance difference between isostructural transition metal disulfides (TMDs) like VS2 and MoS2, which possess similar spacings but vastly different capacities. Herein, we propose an electronic-structure descriptor, φ, defined as the product of the transition metal's d-band center and electronegativity. Density functional theory calculations reveal that φ strongly correlated with Zn2+ adsorption energy (R2 = 0.94). Experimental validation across six synthesized TMDs confirms a definitive volcano-type relationship between Zn2+ storage capacity and φ, while revealing no correlation with interlayer spacing. This work establishes a generalizable screening principle that prioritizes the electronic origin of host-guest interactions over traditional structural metrics, providing a new roadmap for the rational design of intercalation hosts for multivalent-ion batteries.
Nitrification is an essential process within the global nitrogen cycle and also occurs under extreme conditions, such as in geothermal environments. The nitrite-oxidizing group Nitrospira represents key nitrifiers in these systems, as several species inhabit hot springs worldwide. Using different initial incubation temperatures, two novel moderately thermophilic Nitrospira enrichments, Nitrospira sp. Vd2 and Ca. N. neuquenensis E2OT, were obtained from sulfur-rich mud pools in the geothermal field Las Máquinas (Neuquén Province, Argentina). Nitrospira sp. Vd2 belongs to the N. bockiana lineage V, whereas the second enrichment (E2OT) represents the novel taxonomic lineage VIII, together with cultures from Kamchatka (Kam-Ns4a) and Garga hot springs (Ga3a). The vibrioid morphology of Ca. N. neuquenensis E2OT is strikingly different from all described, twisted rod-shaped Nitrospira. Our study expands the knowledge of the taxonomic and genomic diversity of moderately thermophilic Nitrospira, by comparing the high-quality draft genomes with those of previously described species. The recent discovery of quorum-sensing genes outside the Nitrospira lineage II was confirmed for both Argentinian cultures. Notably, the genome GC contents of the enrichments Vd2 and E2OT are 60.6% and 69.4%, respectively. The latter is the highest observed for Nitrospira to date and might support thermotolerance up to 50°C.
Partially crystalline nodules are occasionally discovered within breccias linked to large ignimbrite-forming eruptions, providing evidence of the fragmentation of the plutonic reservoir and conduit system during such eruptions. These nodules offer valuable insights into the magmatic systems fuelling these highly explosive volcanoes. On Tenerife, crystal-rich samples containing interstitial melt are preserved in several Plinian eruption deposits spanning over ~ 1.8 million years, but the crustal architecture and interactions between magma reservoirs beneath the island remain poorly understood. This study focuses on explosively fragmented juvenile nodules from Tenerife's pyroclastic deposits, which provide snapshots of the mush reservoir preceding caldera-forming events. Petrological, major element and trace element analyses were conducted on juvenile nodules from five major caldera-forming eruptions: Caleta (221 ka), Fasnia (312 ka), San Juan (1.50 Ma), Morteros (~ 1.70 Ma), and Gaviotas (1.84 Ma). These nodules preserve a range of crystallisation stages within Tenerife's alkaline magmatic system, uniquely containing interstitial groundmass that existed in a supra-solidus state at the time of eruption, with an average melt content of ~ 25 vol%. Despite macro-mineralogical variability between eruptions, the juvenile nodules exhibit consistent basanite interstitial groundmass chemistry and lithologies, suggest that the mafic mush reservoir beneath Tenerife has remained both chemically and petrologically stable over ~ 1.8 million years. This study provides a new perspective on the stability of the mafic mush reservoir beneath Tenerife, highlighting its persistent role in the volcano's magmatic plumbing system. The chemical consistency of the mush contrasts with the episodic mobilisation and more chemically diverse evolved phonolite melts, underscoring the importance of understanding mid-crustal processes leading to explosive eruptions. These findings provide evidence for a long-lived, stable mush reservoir and a new perspective on the compositional makeup of the crystal-mush reservoirs at defined points in time, enhancing our temporal understanding of ocean island volcanoes and their crustal magma mush reservoirs. The online version contains supplementary material available at 10.1007/s00410-026-02302-3.
Thousands of cubic kilometers of magma lie in the upper crust below supervolcanoes such as Yellowstone (USA), Toba (Indonesia), and Taupo (New Zealand). Most of these systems are identified because of surface geomorphology and eruptive deposits. Recognizing such volcanoes without surface evidence is challenging, causing large magmatic reservoirs to go unnoticed. The Tuscan Magmatic Province, Italy, features only sparse Quaternary volcanic activity, but subsurface data indicate the presence of supercritical fluids at shallow depths. Here we show that more than 5'000 km3 of magma and partial melt are stored in the middle crust of the Tuscan Magmatic Province, Italy. This fuels the high-enthalpy geothermal systems of the region. Such volumes are comparable to those of mid-crust reservoirs beneath recognized supervolcanoes. The discovery of large volumes of magma is critical to explain the long-term evolution of mature magmatic systems and to understand the behavior of large magmatic provinces.
Underwater sediment density currents triggered by marine volcanic eruptions threaten island communities and infrastructure, while their deposits provide archives of past eruptions. Despite their significance, scarce real-time density current observations and concurrent deposit samples limit our understanding of their behaviour and relationship to varying volcanic mechanisms. Using data acquired following the explosive, VEI 6, shallow-submarine eruption of Hunga Volcano in 2022, we show that syn-eruptive delivery of pyroclastic material into the ocean via low-column collapses and fountaining triggered the multidirectional dispersal of highly-concentrated underwater density currents. Rapid supply of > 6.5 km3 of dense pyroclastic material onto the steep volcanic flanks over minutes-to-hours generated currents that maintain high density and velocity 10-100s of kilometres from the volcano. We outline diagnostic criteria to differentiate deposits of shallow-submarine generated underwater currents from other volcanic processes - enabling better reconstruction of the records of volcanic activity in marine sediments and enhancing hazard assessments in submerged volcanic settings worldwide.
The efficiency of plasmon-driven oxidation reactions depends on the ability of plasmon-generated hot holes to reach reactive interfaces. Here, we probe the effective reactive reach of plasmonic hot holes using alkanethiol self-assembled monolayers of varying chain length on Au nanoparticles. Operando photocurrent measurements combined with selective bromide poisoning isolate the contribution of hot holes traversing the molecular layer. The resulting activity exhibits a volcano-type dependence on chain length, with maximum reactivity observed for octanethiol (C8), corresponding to an effective barrier thickness of ∼1 nm. Shorter chains enable rapid charge transfer but increase recombination losses, whereas longer chains hinder hole transport across the molecular layer. These findings demonstrate that plasmon-generated hot holes remain chemically reactive across nanometer-scale molecular barriers, with optimal performance achieved when transport occurs within the tunnelling regime.
This study aims to investigate sex differences in the response to short-term Training Program intervention and the underlying metabolomic mechanisms among obese adolescents. A total of 98 obese adolescents underwent a 4-week, strictly controlled short-term Training Program intervention. Pre- and post-intervention measurements included body morphometry, body composition, lipid metabolism, and glucose homeostasis indicators. Plasma samples were analyzed using targeted metabolomics. Linear mixed-effects models (LMM) were employed to identify Sex-differential Responsive Metabolites, with volcano plots utilized to visualize metabolic regulation preferences between sexes. Hierarchical clustering analysis identified co-regulated metabolic modules within the Sex-differential Responsive Metabolites for pathway analysis. Partial least squares (PLS) regression models were constructed separately for males and females to identify metabolic biomarkers capable of predicting changes in clinical indicators. Post-intervention, both males and females showed significant decreases in weight, body mass index (BMI), chest circumference, waist circumference, hip circumference, waist-to-hip ratio, body water, Body fat mass, fat free mass, skeletal muscle mass, body fat percentage, total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) (P < 0.001). Additionally, HOMA-β levels significantly decreased only in females (P = 0.01). After adjusting for developmental maturity and baseline metabolic risk, the improvements in body fat mass and body fat percentage in males were significantly greater than those in females (both P < 0.01), whereas no statistical differences were found in weight and BMI improvements (P > 0.05). The change in HOMA-β differed significantly between sexes (P = 0.031), with females exhibiting a more pronounced downregulation following the intervention. LMM identified 65 Sex-differential Responsive Metabolites. Hierarchical clustering revealed two co-regulated modules: Module 1 showed a strong upward trend in males but a weak response in females, significantly enriched in the linoleic acid metabolism pathway; Module 2 showed a downward trend in both sexes, but the magnitude of downregulation was more pronounced in males, significantly enriched in pathways related to amino acid catabolism and energy metabolism. PLS model analysis indicated that Sex-differential Responsive Metabolites had predictive capacity for male Fasting Blood Glucose (FBG, R2Y = 0.2653,Q2 = 0.0091), female FBG (R2Y = 0.3552,Q2 = 0.1321), and female LDL-c (R2Y = 0.3895,Q2 = 0.1853). Obese adolescents exhibit significant sexual dimorphism in their response to short-term Training Program. Under the same standardized training program, males achieve greater fat reduction and appear to leverage a synergistic strategy of fatty acid oxidation and protein sparing, whereas females prioritize amino-acid network fine-tuning. Predictive modeling indicates that sex-differential metabolites can predict glucolipid improvements in females. These findings provide a scientific basis for developing sex-differential exercise prescriptions for metabolic health.
In this study, a series of V2O5-MoO3/TiO2 (VMo/Ti) catalysts were prepared using TiO2 supports with varying specific surface area for selective catalytic reduction of NOx by ammonia (NH3-SCR). The activity tests revealed that the NO conversion of different samples showed a volcano-type variation with surface area rising, where the VMo/Ti-S3 catalyst with moderate surface area possessed the best SCR activity (>80% NO conversion at 250 °C). Meanwhile, the SO2 oxidation ratio decreased at an elevated surface area. At 350 °C, the SO2 oxidation ratio of VMo/Ti-S1 catalyst with lowest surface area was about 4.4%, which was around 4 times that of VMo/Ti-S4 sample with highest surface area. Characterization results indicated that, as the surface area increased, both the redox capacity and surface acidity were enhanced. And the vanadium oxides became less polymeric with a gradual increased ratio in dimeric vanadium species and finally more monomer VOx formation, corresponding to the highest SCR activity of VMo/Ti-S3 catalyst. Additionally, the characterization results indicated that the chemisorption of SO2 was inhibited on high-surface-area catalysts, which was consistent with DFT results. And DFT simulations also confirmed an increased energy barrier for SO2 oxidation to generate SO3 process on less polymeric vanadium species. Both the results above indicated the critical role of vanadium polymerization state in SCR activity and SO2 oxidation. This work offers new insights into the development of efficient SCR catalysts with low SO2 oxidation rates for industrial applications.
Metal-free carbon materials are promising catalysts for the electrochemical CO2 reduction reaction (CO2RR). However, the principles for regulating carbon materials still require further discussion. In this context, p-block elements with varying electronegativity may offer extensive opportunities for modulating the electronic properties of the active sites. Herein, density functional theory (DFT) calculations are performed on carbon materials functionalized with p-block elements to reveal their key role in the CO2RR. We systematically screened 14 graphene nanoribbon edge models functionalized with different p-block functional groups (Edge-X/C). The results indicate that the electronegativity of the functional groups serves as a key parameter, which effectively tunes both the p-band center and the surface work function of the carbon atoms. Furthermore, a volcano-shaped relationship was observed between the p-band center and catalytic activity. This indicates that moderate orbital energy levels suppress excessive electron back-donation and promote CO desorption, which are beneficial for the CO2RR. Edge-AsH2/C exhibits the lowest theoretical limiting potential due to the moderate p-band center of its active sites. These insights provide a robust framework for the rational design of high-performance, metal-free electrocatalysts.
The 23 November 2025 eruption of the Hayli Gubbi volcano in Ethiopia generated internal gravity waves that were analyzed using combined observations from the geostationary satellites Himawari‑8 and Meteosat‑9. Several hours of sustained plume emission produced a wave packet embedded within SO2‑rich volcanic air masses, which propagated eastward under strong mid‑ to upper‑tropospheric westerlies. The propagation direction and phase speed matched the 300‑hPa wind field, indicating advection along the subtropical jet. Exceptionally dry conditions within the jet core (relative humidity < 30%) likely helped maintain the volcanic plume and prevented attenuation of the wave signal during long‑range transport. No clear signatures were detected in channels sensitive to the lower troposphere or stratosphere; this likely reflects the absence of any effective wave-trapping structure along the propagation path, which allowed vertical leakage of wave energy and limited downward penetration. This vertical leakage provides a consistent explanation for the lack of detectable signals over Japan in lower‑tropospheric channels. The combined satellite observations show that the wave packet propagated primarily within a narrow mid‑ to upper‑tropospheric layer constrained by background wind and humidity structure. These results demonstrate the value of multi‑satellite observations for detecting eruption‑generated internal gravity waves and highlight the environmental conditions that enable their long‑distance transport.
Understanding how ecological variation shapes skeletal morphology is important for linking observed locomotor behavior to anatomical correlates in extant hominoids, and for the subsequent interpretation of locomotor behavior in extinct taxa. In this study, we investigate ecomorphological variation in the metacarpals and phalanges across all five manual rays within Gorilla, focusing particularly on differences between western lowland gorilla (Gorilla gorilla gorilla) and the Rwandan (Volcanoes National Park) and Ugandan (Bwindi Impenetrable National Park) populations of mountain gorilla (Gorilla beringei beringei). This work incorporates the first substantial set of skeletal measurements from the Bwindi mountain gorilla population, derived from individuals recovered by the Mountain Gorilla Skeletal Project between 2018 and 2025. By comparing these data with samples from low and high-elevation Grauer's gorillas (Gorilla beringei graueri), we assess how variation in arboreality correlates with digit element lengths, demonstrating that the Bwindi mountain gorillas exhibit intermediate metacarpal and phalangeal lengths between the more arboreal western lowland gorillas and the more terrestrial Virunga mountain gorillas. These findings indicate a correlation between longer digital rays in more arboreal populations, even within the same species, which may enhance grasping and stability on arboreal substrates. We show a population-specific relationship between ecology and hand morphology in Gorilla and emphasize the value of documenting localized skeletal responses to environmental and behavioral variation to better interpret patterns in the hominoid fossil record.