Journal of Volcanology and Geothermal Research最新文献

{"title":"Seabed stability inferred from the 2019–2020 earthquake swarm under a volcanic cone field and slopes of Condor Seamount, Azores","authors":"Neil C. Mitchell ,&nbsp;Fernando Tempera ,&nbsp;Thomas A. Morrow ,&nbsp;Joaquim Luis ,&nbsp;Christian Hübscher ,&nbsp;Telmo Morato","doi":"10.1016/j.jvolgeores.2025.108279","DOIUrl":"10.1016/j.jvolgeores.2025.108279","url":null,"abstract":"<div><div>Knowledge of the strength of submarine volcaniclastic deposits is important for assessing the stability of slopes of such materials and their geohazards but is difficult to measure. An opportunity for an alternative evaluation has been presented by an earthquake swarm under a volcanic seamount in the Azores. Attenuation relationships applied to earthquake data suggest that a cone field and flanks of the seamount experienced horizontal accelerations of &gt;0.3 g during the swarm. However, multibeam sonar data collected before and after the swarm suggest that no slope failures occurred. Furthermore, in backscatter data collected after the swarm, low intensities below slopes suggest that muddy aprons were undisturbed by landslide debris. The swarm overlies cones with slopes near typical repose angles of non-cohesive particles. During earthquake shaking, the direction of maximum acceleration deviates from that due to gravity alone. We show that cone slopes effectively experienced much steeper gradients than their repose angles during the swarm. As they survived the shaking without failing, they were effectively stronger than non-cohesive sediment. We use a pseudo-static analysis to investigate the implied sediment strength, finding a ratio of undrained shear strength to vertical stress of &gt;0.4–0.5. This implies shear strength of &gt;24–30 kPa at 10 m depth below seabed. We speculate that carbonate cements and/or compaction may be responsible. If shallow areas are more widely strengthened, slope failure may then be less likely during moderate (M_L ∼ 4.0 or less) seismic shaking and hence be less hazardous than if the slopes comprised wholly non-cohesive materials.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"460 ","pages":"Article 108279"},"PeriodicalIF":2.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical and isotopic characterization of groundwater and thermal waters from the Campi Flegrei caldera (southern Italy)","authors":"Stefano Caliro ,&nbsp;Rosario Avino ,&nbsp;Francesco Capecchiacci ,&nbsp;Antonio Carandente ,&nbsp;Giovanni Chiodini ,&nbsp;Emilio Cuoco ,&nbsp;Carmine Minopoli ,&nbsp;Francesco Rufino ,&nbsp;Alessandro Santi ,&nbsp;Andrea L. Rizzo ,&nbsp;Alessandro Aiuppa ,&nbsp;Vincenzo Allocca ,&nbsp;Pantaleone De Vita ,&nbsp;Mauro A. Di Vito","doi":"10.1016/j.jvolgeores.2025.108280","DOIUrl":"10.1016/j.jvolgeores.2025.108280","url":null,"abstract":"<div><div>We report here on the results of an extensive hydrogeochemical survey of the chemical and isotopic composition of thermal groundwater in the Campi Flegrei caldera (CFc), a restless volcanic system in the Campania Volcanic Province of Southern Italy. Our hydrogeochemical study, based on the collection of 114 groundwater samples, is the first comprehensive one since uplift, seismicity and degassing resumed in 2005, continuing today at accelerating rate. We use our results to characterize the processes that control the wide diversity of groundwater composition observed. We identify a set of key source processes governing the composition of the CFc thermal waters: i) the infiltration of meteoric water, responsible for the formation of diluted cold groundwater having bicarbonate as the prevalent anion (fresh waters), ii) mixing, upon downward infiltration in the aquifer(s), with high-temperature hydrothermal reservoir brines of probable marine origin (chloride waters), iii) the dissolution of a CO₂-He rich magmatic-hydrothermal gas, with isotopic signature (respectively δ¹³C ∼ −1 ‰ vs. PDB and ³He/⁴He ∼ 3Ra, where Ra is the atmospheric He isotope ratio) similar to the Solfatara hydrothermal gases, generating bicarbonate-rich groundwater; (iv) near-surface dilution by hot condensates, formed by partial condensation of H₂S-rich Solfatara like hydrothermal steam, generating sulphate-rich steam heated waters. In near-surface environments, upward migrating groundwater also degases, releasing poorly soluble gas compounds (He, Ar, N₂, CH₄) and becoming enriched in more soluble CO₂. The above processes can work in concert, but each dominates in specific regions of the hydrothermal system, hence causing the extreme spatial diversity of water chemistry observed within the caldera. Our conceptual model for the processes acting within the thermal groundwater system will be crucial to interpreting any temporal change in groundwater chemistry observed in the installed permanent (instrumental) groundwater-monitoring network, which is critically needed for improving geochemical volcano monitoring during current acceleration of the unrest.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"460 ","pages":"Article 108280"},"PeriodicalIF":2.4,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143225965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term thermo-fluid dynamic modeling of Solfatara hydrothermal system, Campi Flegrei caldera","authors":"Andrea Barone ,&nbsp;Gianluca Gola ,&nbsp;Stefano Caliro ,&nbsp;Giovanni Chiodini ,&nbsp;Pietro Tizzani ,&nbsp;Raffaele Castaldo","doi":"10.1016/j.jvolgeores.2025.108277","DOIUrl":"10.1016/j.jvolgeores.2025.108277","url":null,"abstract":"<div><div>Solfatara hydrothermal system lies within the active and densely populated volcanic area of the Campi Flegrei caldera; during bradyseismic crises, the Solfatara crater behaves as a deforming region with intense seismicity and gas emissions. Advancements on multiphysics modeling of this area can therefore provide insights into the relationship between the magmatic and hydrothermal systems of this high-risk caldera. In this work, we performed a 2D numerical modeling describing the long-term thermo-fluid dynamic processes arising beneath the Solfatara crater. This model is innovative since it simulates the evolution of thermal and fluid flow regimes from the system formation, i.e., 4500 yrs. ago, without a priori assumptions about the amount of deep hot CO₂-rich fluid injections. We first collect geological information to define a more refined heterogeneous model integrating well data, rocks density, porosity, permeability, heat capacity, thermal conductivity, surface emissivity parameters and structural elements. We set a steady-state conductive temperature model and use the result as the initial condition for the transient analysis. Then, we performed time-dependent studies by coupling the heat transfer with the fluid flow laws, retrieving an imaging of the hydrothermal system in terms of temperature, density and fluids migration velocity distributions. Our results highlighted the generation of a buoyancy-driven convective cell beneath the Solfatara crater, with a gas zone extending between 1000 and 500 m b.s.l. We conclude by reiterating the importance of this model, which has to be used as a starting scenario for new studies on the evolution of geochemical and geophysical indicators of the Solfatara system.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"459 ","pages":"Article 108277"},"PeriodicalIF":2.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143196308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal and spatial evolution of explosive silicic peralkaline eruptions at the Olkaria Volcanic Complex and Longonot volcano in the Southern Kenya Rift","authors":"P.A. Wallace ,&nbsp;V. Otieno ,&nbsp;P. Godec ,&nbsp;R.W. Njoroge ,&nbsp;M.S. Tubula ,&nbsp;L. Cappelli ,&nbsp;P.M. Kamau ,&nbsp;S. Nomade ,&nbsp;N.O. Mariita ,&nbsp;K. Fontijn","doi":"10.1016/j.jvolgeores.2025.108275","DOIUrl":"10.1016/j.jvolgeores.2025.108275","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Olkaria Volcanic Complex and adjacent Longonot volcano in the Southern Kenya Rift host major geothermal resources yet also pose volcanic hazards owing to their long histories of explosive eruptions. Olkaria is a multicentred dome complex consisting of lava domes, craters and fissures produced following the eruption of peralkaline comenditic rhyolites. Longonot is a trachytic caldera hosting a central summit crater, situated &lt;10 km east of Olkaria, with pumice and ash eruptions being a dominant feature. This study reconstructs their evolution through detailed field, geochemical and geochronological investigations of widespread pyroclastic deposits. Logging sequences of pumice and ash fallout and pyroclastic density current deposits enables establishing a regional stratigraphic framework spanning the past 42 ka. Ten key eruptive units record explosive phases at Olkaria and Longonot, with eight &lt;sup&gt;40&lt;/sup&gt;Ar/&lt;sup&gt;39&lt;/sup&gt;Ar ages and a radiocarbon date providing the first accurate age constraints of both volcanoes. The oldest explosive deposits identified in our field area are associated with the large-magnitude Maiella Pumice (MP) eruptions (338–333 ka), representing one of the first explosive silicic peralkaline eruptions in the Southern Kenya Rift. Within Olkaria, the earliest preserved deposits in our tephrostratigraphic framework are 42–37 ka pyroclastic density currents (OP) and pumice fallouts (OFB) representing early rhyolitic dome eruptions. Overlapping deposits reveal Longonot concurrently experienced repetitive large explosive eruptions emplacing pumice fall deposits from 37 ka to 17 ka (LAP). After 17 ka, LAP eruptions were punctuated by a single eruption of mixed basaltic trachyandesite, trachyandesite and trachyte pumice (LMx), followed by persistent trachyte ash venting at Longonot (LA1). Simultaneously, Olkaria transitioned to localised lava dome construction and collapse generating block-and-ash flows from 17 ka to 14 ka (OD1–2). Younger Longonot ash eruptions (LA2) and recent 191 ± 23 cal yr BP effusive–explosive activity at Olkaria's Ololbutot centre (OD3) reveals both volcanoes have remained active throughout the Holocene. Minimum estimated magnitudes for widespread fall units at both systems range between 4 and 5 (DRE deposit volumes of 0.04–0.35 km&lt;sup&gt;3&lt;/sup&gt;), representing substantial regional hazards, with eruption frequencies averaging up to one moderate–large eruption (magnitude 4–5) every ∼2000 years for Longonot and one small–moderate explosive eruption (magnitude ∼3) every ∼200 years for Olkaria until ca. 10 ka, after which eruptions are significantly smaller and more localised. Statistical analysis of pumice glass geochemistry enables the fingerprinting of Olkaria deposits to likely source vents, tracking spatial-temporal variability across the complex. The larger explosive eruptions at both Olkaria and Longonot dispersed voluminous pyroclastic material (pumice and/or ash), which generated up to 1-m-t","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"460 ","pages":"Article 108275"},"PeriodicalIF":2.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143225773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monogenetic volcanism fed by complex magmatic processes: El Negrillar volcanic field (Central Andes, Chile)","authors":"Deborah Cáceres-Baez ,&nbsp;Patricia Larrea ,&nbsp;Teresa Ubide ,&nbsp;Jo Roberts ,&nbsp;Camila Loaiza","doi":"10.1016/j.jvolgeores.2025.108273","DOIUrl":"10.1016/j.jvolgeores.2025.108273","url":null,"abstract":"<div><div>Gaining insight into the feeding systems and pre-eruptive processes of monogenetic volcanic fields is crucial to better understand the genesis and potential hazards of monogenetic volcanoes. This study examines pre-eruptive processes at El Negrillar volcanic field in Chile through the analysis of mineral cargo in time-constrained (982 ± 8 to 141 ± 72 ka) samples. With 51 eruptive centers, 98 lava flows, and minor phreatomagmatic deposits distributed into three clusters aligned NE-SW, El Negrillar encompasses the largest volume of erupted magma among the Pleistocene monogenetic volcanoes in the Central Andes. The samples range from basaltic andesite to dacite, and have microporphyritic textures with microphenocrysts of olivine, pyroxene, plagioclase and amphibole embedded in a hypocrystalline to holocrystalline groundmass. Based on the analysis of mineral compositions and their textures, fractional crystallization represents the primary differentiation process of El Negrillar magmas during their ascent to the surface. In addition, mineral disequilibrium textures further record evidence of magma recharge, mixing, assimilation, and recycling processes in the thickened crust context of the Central Andes, leading to the eruption of evolved antecrysts and xenocrysts within relatively primitive magmas. The crystallization sequence begins with the appearance of olivine (1180–1110 °C), followed by plagioclase (1120–1030 °C), pyroxene (1110–1010 °C), and in a later stage, amphibole (960–930 °C) microphenocrysts, within a main stagnation zone located in the upper mid-crust (2.5–5.0 kbar; ∼ 9–19 km depth). A compositional evolution from the southwest to the northeast across El Negrillar is evident through whole-rock and mineral chemistry, indicating the involvement of several, similar parental magmas that stalled in a network of small sills within the main stagnation zone, where microphenocrysts grew before ascent to the surface. These findings challenge the traditional view of monogenetic systems as simple source-to-surface magma channels, instead revealing a surprising level of petrological complexity marked by limited stagnation and intricate compositional changes tied to the pre-eruptive history.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"459 ","pages":"Article 108273"},"PeriodicalIF":2.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143196307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term development of lava dome morphology and thermal energy release in the crater of Mount St. Helens, Washington (USA)","authors":"Linda Sobolewski ,&nbsp;Christian Stenner ,&nbsp;Lee J. Florea ,&nbsp;Guy McWethy ,&nbsp;Andrea I. Gomez-Patron ,&nbsp;Edgar U. Zorn ,&nbsp;Artur Ionescu ,&nbsp;Eduardo Cartaya ,&nbsp;Andreas Pflitsch","doi":"10.1016/j.jvolgeores.2025.108274","DOIUrl":"10.1016/j.jvolgeores.2025.108274","url":null,"abstract":"<div><div>The crater of Mount St. Helens has undergone significant changes since the end of the 2004–2008 eruption cycle. Heat output from the new lava dome has decreased constantly in different phases of cooling. At the same time, the lava dome morphology changed, including substantial subsidence. Herein we present long-term dome evolution within the St. Helens crater by combining field investigations and remote sensing data. Repeated surveys of subglacial caves provide evidence for a new phase of dome cooling and reduced fumarolic activity. While the caves remained consistent or became larger before 2022, the latest field campaigns in 2023 indicated a strong volume reduction. One example is Mothra Cave, which reduced from 797.4 to 189.8 m in surveyed length in one year (2022 to 2023). These observations are supported by decreasing fumarole temperatures in/near the cave systems located at the dome flanks (trending towards 0 °C) as well as decreasing fumarole temperatures at the dome summit (∼380 °C in 2014/2015, ∼90 °C in 2021; ∼60 °C in 2024). Although ASTER data similarly revealed an overall cooling of the lava dome, field investigations enabled a more precise determination of the temperature distribution. As revealed by LiDAR data, the new 2004–2008 lava dome decreased in elevation more than 35 m from 2009 to 2019. In contrast, almost no elevation change was observed at the old 1980–1986 dome. The elevation loss is strongly related to initial dome growth structures. Drone images further characterized structures on the new dome, demonstrating correlations between fumarolic areas and substrate and morphology. Since lava dome degradation is associated with numerous hazards, information about their long-term development as well as the comparison between various parameters and their response time can contribute to hazard forecasts.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"460 ","pages":"Article 108274"},"PeriodicalIF":2.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143226094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volcanic history and magma systems of Lake Monoun Polygenetic Maar, Noun Plain, Western part of the Cameroon Volcanic Line: Constraints from stratigraphy, chronology and geochemistry","authors":"Linus Anye Nche ,&nbsp;Takeshi Hasegawa ,&nbsp;Festus Tongwa Aka ,&nbsp;Takeshi Ohba ,&nbsp;George Teke Mafany ,&nbsp;Károly Németh ,&nbsp;Yasuo Miyabuchi ,&nbsp;Yasuaki Kaneda ,&nbsp;Asobo Nkengmatia Elvis Asaah ,&nbsp;Patrick Mendi Wajiba ,&nbsp;Caroline Neh Ngwa ,&nbsp;Joseph Legrand Tchop ,&nbsp;Pauline Wokwenmendam Nguet ,&nbsp;Ntepe Nfomou ,&nbsp;Cheo Emmanuel Suh ,&nbsp;Wilson Yetoh Fantong ,&nbsp;Farouk Oumar Mouncherou","doi":"10.1016/j.jvolgeores.2025.108265","DOIUrl":"10.1016/j.jvolgeores.2025.108265","url":null,"abstract":"<div><div>Lake Monoun (LM) is a maar volcano located on the Cameroon Volcanic Line in West-Central Africa. In 1984, a limnic eruption occurred at LM, releasing large amounts of magmatic CO₂ gas that had accumulated in the lake. The CO₂ gas asphyxiated 37 people in the surrounding area. Despite this hazard, the volcanic history of LM maar remains unknown. This study presents the first comprehensive results of lithostratigraphy, physical volcanology, ¹⁴C dating and petrology of LM eruptive products. The lake has a WSW-ENE-aligned morphology with three main craters, the walls of which expose tephra and lava that can be divided into 5 stratigraphic units (A, B, C, D, and E from bottom to top). Unit A, a pyroclastic surge deposit in the NW, was produced by a phreatomagmatic eruption and deposited on a thick (ca.170 cm) paleosol developed on granitic basement. The paleosol yields a ¹⁴C age of ca 1.3 cal. ka. Units B (weathered scoria fall) and C (lava flow) in the NW part of the lake were respectively produced by strombolian and effusive eruptive activities. The SE side consists of unit D (scoria fall) a product of violent strombolian activity and unit E (voluminous surge) deposited by phreatomagmatic activity. The surge deposits of units A and E are rich in lithic fragments such as granite and lava, indicating subterranean excavation of country (accidental) and volcanic (accessory) rocks. A short time break represented by thin (ca. 15 cm, 0.1–0.3 cal. ka) paleosol can be recognized between units A and E in the distal facies. Based on the temporal and spatial distribution of these deposits, the eruption history of LM can be grouped into two stages. The first stage led to the development of the western and central craters and is recorded by units A to C in the NE section. The second stage proceeded after a short hiatus represented by the thin paleosol and a shift of the eruptive locus to the SE part of the lake. This gave rise to the largest eastern crater characterized by well-preserved units D and E. The LM case study reveals a potential time-space evolutionary pathway for crater formation, implying a polygenetic origin. Juvenile materials from the units are basanitic in composition with narrow chemical variation, suggesting a common magma system through the two stages. Silica content gradually increases from units A to E (SiO₂ = 43.4 to 45.8 wt%), suggesting that the magma was differentiated with time (from units A to E) and tapped from the whole part of the chamber at unit E. Accessory lava fragments in units A and E display three distinct geochemical trends, composed of alkali and subalkaline basalts, implying the presence of diverse magma systems around the area prior to the maar formation.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"460 ","pages":"Article 108265"},"PeriodicalIF":2.4,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143225772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cost-effective GNSS as a tool for monitoring volcanic deformation: A case study on Saba in the Lesser Antilles","authors":"Andreas Krietemeyer ,&nbsp;Elske van Dalfsen","doi":"10.1016/j.jvolgeores.2024.108263","DOIUrl":"10.1016/j.jvolgeores.2024.108263","url":null,"abstract":"<div><div>We present the design and positioning results of four cost-effective Global Navigation Satellite System (GNSS) units deployed on Saba, Caribbean Netherlands. Despite harsh environmental conditions and initial prototyping challenges the units function well. Each unit costs less than €1.000 and integrates solar charging capabilities, data logging and data transmission via the introduced 4G extension. The positioning performance of the cost-effective units is comparable to those of conventional permanent GNSS stations on the island, with standard deviations in the horizontal and vertical components within 2–4 mm and 6–9 mm, respectively. The cost-effective units can be used to expand existing GNSS monitoring networks or to build stand-alone networks in budget-constrained environments. Their rapid deployment solution makes them suitable for hazardous applications. Future improvements to the current Printed Circuit Board (PCB) design, implementing the presented changes, are anticipated. The schematics of the PCBs, material lists, and software are made available to the community.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"459 ","pages":"Article 108263"},"PeriodicalIF":2.4,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143196316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geothermal resources of Réunion Island, Indian Ocean, studied by noble gas systematics in thermal springs","authors":"Emilie Roulleau ,&nbsp;Daniele L. Pinti ,&nbsp;Vincent Famin ,&nbsp;Bhavani Bénard ,&nbsp;Nicolas Vinet ,&nbsp;Angeline Bulot ,&nbsp;Céline d'Angelo ,&nbsp;Mathieu Claudon ,&nbsp;Joséphine Gambiez ,&nbsp;Noémie Bouche","doi":"10.1016/j.jvolgeores.2024.108260","DOIUrl":"10.1016/j.jvolgeores.2024.108260","url":null,"abstract":"<div><div>La Réunion Island, home to the volcanoes Piton des Neiges and Piton de la Fournaise, hosts active hydrothermal systems fueled by a long-standing mantle plume. Understanding these systems is crucial for predicting their future potential as a geothermal resource. In this work, noble gases (Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), and Xenon (Xe)) were analyzed in 16 thermal springs to gain insights into fluid and heat sources as well as their pathways. Their helium isotopic composition or ³He/⁴He ratio is 13.9 ± 0.4 times higher than the atmospheric ratio (1.384 × 10⁻⁶). This ratio is comparable to those found in cumulates and xenoliths, associated with the Réunion mantle plume. Some samples show lower ³He/⁴He values than the plume source, indicating the addition of locally produced radiogenic ⁴He, likely from syenitic and basaltic products of Piton des Neiges and Piton de la Fournaise. The elemental (⁸⁴Kr/³⁶Ar and ¹³²Xe/³⁶Ar) and radiogenic noble gas ratios (⁴He/⁴⁰Ar*) appear to be influenced by magma degassing and, to a lesser extent, by boiling and recondensation of fluids in the shallower part of the hydrothermal circuit. This is supported by the heat/helium (Q/³He) ratio which indicates that mantle degassing mainly controls the transfer of heat and helium through convection at the interface between the magmatic source and the geothermal system. The distribution of helium isotopic composition of fluids suggests that the heat sources feeding the geothermal system reach maximum values in two zones: the cirque of Cilaos (a circular depression south of Piton des Neiges) along an N30° rift zone and the east of Réunion Island along the N120° rift zone between the two volcanoes. These zones are the most promising targets for future geothermal exploration.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"459 ","pages":"Article 108260"},"PeriodicalIF":2.4,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143196315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to Insights into the development of small-volume long lava flows: A case study of the Coalstoun Lakes Volcanic Field, southeast Queensland, Australia [JVGR, 451 (2024)].","authors":"Catherine Brown,&nbsp;Scott Bryan,&nbsp;David Gust,&nbsp;Hayden Dalton","doi":"10.1016/j.jvolgeores.2024.108231","DOIUrl":"10.1016/j.jvolgeores.2024.108231","url":null,"abstract":"","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"456 ","pages":"Article 108231"},"PeriodicalIF":2.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}