Geothermics最新文献

{"title":"Latest trends and new approaches in ground source heat pump systems: A comprehensive review of performance, sustainability, and future directions","authors":"Abdul Karim ,&nbsp;Kwonye Kim ,&nbsp;Hobyung Chae ,&nbsp;Jinhwan Oh ,&nbsp;Yujin Nam","doi":"10.1016/j.geothermics.2025.103515","DOIUrl":"10.1016/j.geothermics.2025.103515","url":null,"abstract":"<div><div>According to a recent International Energy Agency (IEA) report, ground source heat pump (GSHP) technology is receiving increasing attention as it can play a major role in carbon neutrality and building energy reduction. GSHP systems have been applied to commercial buildings since the 1960s and have evolved through the adoption of diverse technological innovations. GSHPs are recognized as a key carbon-reduction technology and have been studied mainly in North America and Northern Europe. However, considerable research and development is being conducted in Asia, and the number of applications in large buildings is also increasing. In this study, research publications and operation data of GSHP systems over the past 15 years were analyzed to examine the trends in the research focus and system performance. Furthermore, the performance of GSHP systems was analyzed by region and climate based on the system performance data obtained from experiments and analysis, and the differences were quantitatively presented. As a result, the average coefficient of performance COP of the GSHP system in actual operation was 4.7 for cooling and 4.2 for heating. Moreover, higher latitude were found to be more favorable for cooling performances, whereas lower latitudes were more favorable for heating.Over the past 15 years, GSHP research has expanded beyond ground heat exchanger designs, hybrid technologies, and AI-driven optimization to include emerging topics such as energy geostructures, integration with district heating and cooling networks, advanced sensing and Digital Twin frameworks, and long-term thermal energy storage, with much of this work concentrated in Northeast Asia and Europe.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103515"},"PeriodicalIF":3.9,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrochemical appraisal, formation mechanism, and sustainable development of fold-type geothermal waters: Insights from hydrochemistry and isotopes","authors":"Xun Huang ,&nbsp;Xingcheng Yuan ,&nbsp;Xiyong Wu ,&nbsp;Ying Wang ,&nbsp;Shiming Yang ,&nbsp;Shuang Zhao ,&nbsp;Yangshuang Wang ,&nbsp;Yunhui Zhang","doi":"10.1016/j.geothermics.2025.103518","DOIUrl":"10.1016/j.geothermics.2025.103518","url":null,"abstract":"<div><div>To achieve the goals of carbon peak and carbon neutrality, geothermal energy, as a clean, renewable, and pollution-free natural resource, has attracted attention worldwide. The Sichuan Basin in China is rich in geothermal resources, especially in the fold structure area on the southeast side. However, research on the region's formation mechanisms and quality evaluation is lacking, hindering further geothermal resource development. In this study, the hydrochemical and isotopic characteristics of 27 geothermal water samples from the fold structure area of the southeastern Sichuan Basin were investigated to elucidate the formation mechanism of geothermal water and evaluate its quality. The discharge temperatures of geothermal waters range from 32.5 to 52 °C; they have neutral pH values and are brackish with hydrochemical types classified as SO_4<img>Ca and SO_4<img>Ca·Mg. The results of δ_D and δ¹⁸O analysis show that the geothermal water comes from the recharge of meteoric waters. The recharge elevation and temperature are 528−1212 m and 8.5 − 14.5 °C, respectively, and geothermal waters flow along anticlinal cores from NE to SW. The main factors controlling the hydrochemical evolution of geothermal waters are calcite, dolomite, and gypsum dissolution in Triassic carbonate rocks, followed by silicate minerals and halite. Reservoir fluids are primarily composed of free ions such as Na⁺, Ca²⁺, and Mg²⁺, as well as complexes like CaHCO₃⁺, CaSO₄, and MgSO₄. The shallow reservoir temperatures of geothermal waters range from 52 °C to 96 °C, with 20−83% of cold waters mixed with deep geothermal fluids during the rising process. The initial reservoir temperatures before mixing are between 62 °C and 183 °C, and the circulation depths range from 1383 m to 2619 m. The eastern part of the study area is the most promising development area due to its high reservoir temperatures (&gt;90 °C) and enriched minor elements (Sr and F). However, attention should be paid to the scaling of CaCO₃ and CaSO₄ and the treatment of high SO₄²⁻-concentration wastewater in the development process. The research results reveal both the formation mechanism of geothermal waters and the distribution characteristics of geothermal resources, while providing valuable insights for their development in fold structure areas.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103518"},"PeriodicalIF":3.9,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation of the heat transfer characteristics of supercritical CO2 in a single granite fracture","authors":"Biao Shu ,&nbsp;Linyu Xiang ,&nbsp;Sen Zhang ,&nbsp;Joseph Moore","doi":"10.1016/j.geothermics.2025.103517","DOIUrl":"10.1016/j.geothermics.2025.103517","url":null,"abstract":"<div><div>The use of supercritical carbon dioxide (ScCO₂) for heat transfer has the potential to improve the efficiency of geothermal extraction in Enhanced Geothermal Systems. In this study, experiments were conducted to investigate the effects of reservoir temperature and confining pressure on the hydraulic and heat transfer characteristics of ScCO₂ in a granite fracture. Experiments were also conducted to compare the heat transfer characteristics of ScCO₂ and water. At constant confining pressure, the heat transfer coefficients of ScCO₂ decrease by an average of 63.8 %, 73.7 %, and 83.5 % as the reservoir temperature increases from 50 to 100, 150, and 200 °C, respectively. The reservoir temperature governs the thermophysical properties of ScCO₂, and therefore the heat transfer coefficient. The specific heat capacity and density of ScCO₂ contribute much more to the heat transfer coefficient than the viscosity. As the confining pressure increases from 10 to 15, 20, and 25 MPa, the heat transfer coefficient decreases by 18.6–31.6 %, 30.6–46.0 %, and 41.3–54.7 % at reservoir temperatures of 50–200 °C, respectively. At low-medium temperatures, the heat transfer coefficient of ScCO₂ is 1.8 to 7.1 times higher than that of water. The findings can provide a theoretical basis for improving the efficiency of geothermal energy extraction and optimizing the design of Enhanced Geothermal Systems.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103517"},"PeriodicalIF":3.9,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical behavior of rare earth elements in high-arsenic hot springs in southern Tibet (China): New findings on arsenic enrichment","authors":"Lu Ge,&nbsp;Hongbin Tan,&nbsp;Fei Xue","doi":"10.1016/j.geothermics.2025.103516","DOIUrl":"10.1016/j.geothermics.2025.103516","url":null,"abstract":"<div><div>Hot springs in the southern Tibetan Plateau exhibit abnormally high concentrations of arsenic (As). However, the mechanisms responsible for As enrichment are still under debate. Rare earth elements (REE), which serve as effective tracers of water-rock interactions in geothermal systems, provide valuable insights into identifying As sources and enrichment processes. In this study, two representative hot spring systems were investigated: Buxionglanggu (BXLG), a magmatic geothermal system, and Quzhuomu (QZM), a non-magmatic geothermal system. The geochemical characteristics of REE in the hot springs are analyzed to determine their distribution and fractionation patterns, and to explore their indications for As enrichment. Fe oxides/hydroxides play a dominant role in controlling REE concentrations. Calculations of REE complexes show that carbonate complexes dominate in samples with pH values of 7–8 and water temperatures below 70 °C, whereas oxyhydroxide complexes prevail at pH ≥ 8 and temperatures &gt; 70 °C. Chondrite-normalized REE patterns display differences between the two systems: BXLG shows enrichment in LREE and HREE, while QZM displays varying degrees of LREE enrichment. REE fractionation is influenced by multiple geochemical processes: (1) During water-rock interaction, HREE and MREE are preferentially leached from host rocks, resulting in a leftward tilt in the REE pattern observed in BXLG hot springs compared to their host rocks, whereas QZM hot springs largely preserve the REE signature of the source rocks; (2) Adsorption and desorption processes mediated by Fe oxide/hydroxide colloids play a significant role in REE fractionation, as evidenced by the strong positive correlation between LREE and Fe concentrations; (3) pH and temperature collectively influence the distribution and fractionation of REE complexes in hot spring waters. Notably, the As concentrations (average 953.2 µg/L) and As/ΣREE values (average 11,717) in the BXLG hot springs are significantly higher than those in the QZM hot springs (mean As concentrations of 49.6 µg/L and mean As/ΣREE of 782). These significant differences between the two hot spring systems suggest distinct sources of As. In the QZM hot springs, As is primarily derived from water-rock interactions, whereas magmatic fluids are predominantly responsible for As enrichment in the BXLG hot springs. Moreover, positive Ce and Eu anomalies may serve as potential geochemical indicators of As enrichment, with higher Eu/Eu* values correlating with elevated As concentrations.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103516"},"PeriodicalIF":3.9,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145424347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical evidence for fluid provenance and hydrothermal alteration processes in sub-salt units of the Northern Red Sea","authors":"Peter Birkle ,&nbsp;Philip J. Ball","doi":"10.1016/j.geothermics.2025.103514","DOIUrl":"10.1016/j.geothermics.2025.103514","url":null,"abstract":"<div><div>For the first time in the Red Sea region, sub-salt aquifers from the northern part of the deep proximal rift basin were assessed on the provenance of formation water, flow dynamics, and hydrothermal alteration processes. Five preserved bottomhole water samples were recovered from Upper Cretaceous and Lower Miocene sedimentary units from three offshore exploratory wells, analyzed on their hydrochemical (major elements, trace elements) and multi-isotopic composition (δ²H, δ¹¹B, δ¹³C, ¹⁴C, δ¹⁸O, δ³⁷Cl, δ⁸¹Br, ⁸⁷Sr/⁸⁶Sr), and compared with different brine manifestations in the Middle East. NaCl type, brackish water (Red Sea Low Salinity Water, RS-LS) infiltrated nearby the Red Sea coastal area. Toward the interior part of the Red Sea basin, seawater evaporation in a sabkha-type surface environment preceded the infiltration of Na-Ca-Cl type, hypersaline Red Sea Formation Brine (RS-FB) with a mineralization of up to 348,000 mg/l, likely triggered by a global sea-level drop during Last Glacial Maximum. ¹⁴C concentrations from 3.73 ± 0.06 to 10.1 ± 0.14 pMC (percent Modern Carbon) for RS-FB and 2.12 ± 0.04 to 13.3 ± 0.1 pMC for RS-LS reveal a residence time of 17,998 ± 60 - 32,735 ± 150 yr BP (years Before Present) for the Red Sea basin aquifer systems. The infiltration of surface water occurred through vertical flow pathways along normal fault planes of hanging-walls. Overlapping carbon-14 ages for aquifers from the Red Sea Basin and the Upper Mega Aquifer System on the Arabian Platform suggest a common recharge event during Late Pleistocene period on the Arabian Peninsula under humid paleo-climatic conditions. Distinct ⁸⁷Sr/⁸⁶Sr ratios between RS-FB (0.707307 - 0.707350) and Mid-Miocene evaporites (0.70890 - 0.70898) exclude secondary dissolution of halite as feasible brine-forming mechanism for the studied sub-salt units. Intermediate ⁸⁷Sr/⁸⁶Sr signatures of RS-FB fluids (⁸⁷Sr/⁸⁶Sr = 0.707307 – 0.707350) between present seawater (0.7092) and Rea Sea volcanic basement (0.70269 - 0.70315), plus the presence of partially albitized feldspar and kaolinite in basement basalts, suggest a deep-circulating, active hydrothermal convective system with a calculated strontium contribution of 29% from ⁸⁷Sr/⁸⁶Sr -depleted basalts. A positive ¹⁸O shift (δ¹⁸O up to +6.4‰) reflects the occurrence of secondary hydrothermal water rock interaction processes. δ³⁷Cl ratios between -0.23‰ ± 0.11 and 0.18‰ ± 0.09 indicate dynamic groundwater flow, contrasting to generally ³⁷Cl-depleted static sedimentary pore fluids. δ¹¹B values from 17.2 to 28.2‰ point to clay desorption as mechanism to accumulate kaolinite and illite in the Miocene and Cretaceous aquifer strata.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103514"},"PeriodicalIF":3.9,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145424348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geothermal dynamics of Paleozoic sedimentary systems influenced by Precambrian basement highs and elevated hydrodynamic regimes in the Forebulge zone of the Llanos Basin, Colombia","authors":"Jose Ricardo Sandoval-Ruiz ,&nbsp;Sergio Alberto Jerez-Mogollón ,&nbsp;Edgar Ricardo Pérez-Carrillo ,&nbsp;Davis Emerson Suarez-Landazabal ,&nbsp;Ricardo Andrés Gómez-Moncada ,&nbsp;Iliana Karen Copete-Murillo ,&nbsp;Nicolás Pérez-Consuegra ,&nbsp;Andrés Mora ,&nbsp;Jorge Eduardo Sandoval-Muñoz ,&nbsp;Darwin Mateus-Tarazona ,&nbsp;Cristian Ricardo Mendoza-Blanco ,&nbsp;William Mauricio Agudelo-Zambrano ,&nbsp;Nelson Sánchez-Rueda ,&nbsp;Eduin Orlando Muñoz-Mazo ,&nbsp;Silvia Carolina Jerez-Arenas","doi":"10.1016/j.geothermics.2025.103501","DOIUrl":"10.1016/j.geothermics.2025.103501","url":null,"abstract":"<div><div>The geodynamic framework of the geothermal system in the southern Llanos Basin was evaluated using a multiproxy analytical approach integrating geothermal gradient estimation, 3D geological modeling, and detailed hydrogeochemical analyses. Geothermal gradients ranging from 20.0°C/km to 66.7°C/km were calculated from 164 reservoir temperatures derived from PVT tests across 100 oil wells, with recorded temperatures varying between 60.5°C and 133.3°C. The geological model, developed from seismic, structural, petrographic, and petrophysical data, enabled the delineation of lithological sequences and fault-controlled basement highs, and provided insights into reservoir architecture and hydrothermal fluid connectivity. Porosity in Paleozoic units reached up to 23.2%, indicating adequate permeability for geothermal fluid flow. Analyses of 329 water samples, including major ions and stable isotopes, revealed water-rock interactions, mixing processes, and meteoric water influence. Two prospective geothermal zones were identified, coinciding with elevated geothermal gradients, surface recharge areas, and intense fracturing. At depths of ∼3.0 km, predicted reservoir temperatures approach 150 °C, suggesting conditions suitable for geothermal energy generation. These findings highlight geothermal ‘sweet spots’ for exploratory drilling and future developments.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103501"},"PeriodicalIF":3.9,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using fault mapping and infrared UAV survey for thermal water prospection along the southern shore of Lake Baikal: a case study","authors":"Oksana V. Lunina,&nbsp;Ivan A. Denisenko,&nbsp;Anton A. Gladkov","doi":"10.1016/j.geothermics.2025.103512","DOIUrl":"10.1016/j.geothermics.2025.103512","url":null,"abstract":"<div><div>The current study aimed to identify possible prerequisites for the discovery of deep thermal waters along the southern shore of Baikal Lake between the villages of Mangutai and Solzan. The results of morphotectonic and structural mapping during the present investigation revealed that the NW-SE trending South Baikal, Utulik, and Coastal faults, particularly in their junctions with the NE-SW and NNE-SSW trending faults, are the most favorable for groundwater discharge. The infrared unmanned aerial vehicle survey carried out along the coastal strip for 37 km at night, discovered several anomalies. For this purpose, anomalies associated with green vegetation, locations where rivers enter Lake Baikal, areas where warm water flows from natural coastal water reservoirs, and anomalies generated by industrial activity were excluded. Finally, increased fracture density at m² and m³ units, permeable faults, and the most apparent thermal anomalies indicated the most promising locations for further investigation. The anomaly close to the village of Utulik, where hot water may contain sufficient radon for therapeutic purposes, was defined as a priority. The overall results, as well as the structural and lithological similarity between the research area and other promising sites on the eastern coast of Lake Baikal, point to the presence of a geothermal reservoir at depth in the sediments of the Utulik-Solzan depression and the adjacent part of Lake Baikal. Other research are required to appraise geothermal resources and make judgments about future searches for thermal waters.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103512"},"PeriodicalIF":3.9,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the impact of injection duration on the induced seismic hazard","authors":"Mohammad J.A. Moein ,&nbsp;Cornelius Langenbruch ,&nbsp;Serge Shapiro","doi":"10.1016/j.geothermics.2025.103509","DOIUrl":"10.1016/j.geothermics.2025.103509","url":null,"abstract":"<div><div>Developing geoenergy technologies such as Enhanced Geothermal Systems (EGS) requires underground fluid injection operations, which, under certain conditions, can induce large-magnitude earthquakes. To mitigate the seismic hazard, various injection protocols have been proposed to regulate operational parameters. This study evaluates the impact of injection protocol on induced seismic hazard, using theoretical models, numerical simulations and field data. Within the theoretical framework, perturbed rock volume was inferred from the concept of triggering front that serves as a proxy for pressure perturbation, whereas numerical modeling captured the spatio-temporal evolution of pore-pressure. Our results indicate that short-duration injection protocols are likely characterized by lower seismic hazard, as they perturb smaller areas of pre-existing critically stressed faults. This decreases the likelihood of larger ruptures, that might propagate beyond the pressurized rock volume. Given the same (net) injected fluid volumes and geological conditions, the duration emerges as a key factor controlling the extent of the perturbed rock mass. The findings are further illustrated by the 2017 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span> 5.4 Pohang earthquake, which was triggered by the hydraulic stimulation of the nearby EGS. Previously in 2006, the injection of roughly similar fluid volume in Basel induced an earthquake of magnitude <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span> 3.4. This difference in energy release is likely linked to the duration of the injection protocols, being approximately 600 days at Pohang and 6 days at Basel. Our findings highlight the importance of injection protocol, detailed subsurface characterization and real-time seismic monitoring of perturbed rock volumes to mitigate the seismic hazard during EGS developments.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103509"},"PeriodicalIF":3.9,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The heat accumulation effect enhanced by groundwater convection in Karst Geothermal Systems: a case study of karst geothermal reservoirs in the Jizhong Depression, Bohai Bay Basin, North China","authors":"Yang Luo ,&nbsp;Song Rao ,&nbsp;Yizuo Shi ,&nbsp;Xiaoqing Ren ,&nbsp;Jin Na ,&nbsp;Xiaorong Gao ,&nbsp;Shengbiao Hu","doi":"10.1016/j.geothermics.2025.103511","DOIUrl":"10.1016/j.geothermics.2025.103511","url":null,"abstract":"<div><div>The karst geothermal reservoir in northern China exhibits high vertical permeability and horizontal runoff conditions due to the development of cavities and fractures, resulting in large water yields and facilitating the reinjection of tailwater after geothermal utilization, thus offering significant development potential. In karst geothermal systems, fluid convection rapidly transfers heat, leading to pronounced local thermal anomalies. Consequently, quantitative evaluation of the heat accumulation effect of groundwater convection holds particular significance for understanding the genesis mechanisms of karst geothermal resources. The karst geothermal reservoir in the Jizhong Depression of the Bohai Bay Basin is well-developed, serving as a demonstration area for geothermal resource exploitation and utilization. Through coupled numerical simulations of the temperature field and hydrodynamic field, this paper focuses on the combined effects of forced and free convection in the karst geothermal reservoir of the Jizhong Depression and their heat accumulation effects. Additionally, it systematically investigates the impacts of the thickness, permeability of the karst geothermal reservoir, and fault zone width on the heat accumulation effect. Two-dimensional finite element numerical simulation results indicate that topography-driven fluids can promote the movement of convection cells, thereby enhancing the heat accumulation effect of groundwater convection. In karst geothermal systems, as the thickness, permeability of the karst geothermal reservoir, and fault width increase, the following outcomes are observed: enhanced cold water recharge upstream leads to a decrease in the average temperature of the karst geothermal reservoir; thermal plumes advance towards the downstream part of the basin; and the surface heat flux decreases upstream while increasing downstream, indicating an enhancement in the heat accumulation effect of groundwater convection activities.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103511"},"PeriodicalIF":3.9,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Updated 3D resistivity model of the Tres Vírgenes geothermal field (Mexico) from magnetotelluric data: Implications for geothermal exploration and development","authors":"Javier González-Garcia ,&nbsp;Martyn Unsworth ,&nbsp;Oscar Campos-Enríquez ,&nbsp;Yanet Antayhua-Vera","doi":"10.1016/j.geothermics.2025.103506","DOIUrl":"10.1016/j.geothermics.2025.103506","url":null,"abstract":"<div><div>A case study is presented involving the 3D inversion of a legacy magnetotelluric (MT) dataset from the Tres Vírgenes Volcanic Complex (TVVC), Baja California Sur, Mexico, which is a significant geothermal energy resource with an installed capacity of 10 MWe. The MT dataset consists of 76 stations acquired between 1992 and 1999 (bandwidth: 0.003 – 100 Hz), and was previously analyzed using 1D, 2D, and 3D approaches, revealing a layered resistivity structure. However, significant uncertainty surrounds the capability of this dataset to resolve deep resistivity structures associated with the magmatic system. This study applies a 3D inversion approach that incorporates topography and bathymetry and inversion tests to assess the sensitivity of the model features to the data. Well-logs and laboratory measurements of resistivity were used to constrain the interpretation. The integrated methodology enabled a more accurate delineation of the resistivity structure of the TVVC, mapping an extensive conductor primarily associated with a brine-saturated smectite clay cap (10 – 60 % clay fraction, 150 – 200 °C). Internal variability within the conductor suggests the presence of a small sill with andesitic mush (30 – 85 % melt fraction) north of El Azufre Volcano, possibly associated with sulphate-type hydrothermal activity along the El Azufre Fault Zone. Moreover, a zone of lower resistivity to the north of the main conductor suggests a possible intrusion of seawater that remains isolated from the main hydrothermal systems in TVVC. Sensitivity tests indicate that the dataset lacks the resolution required to image deep bodies beneath the main conductor; consequently, deep conductors modelled in previous studies are likely inversion artifacts, and are unrelated to the deep magmatic system. These findings have the potential to improve the delineation of the geothermal system boundaries, and provide insights for future geothermal and magnetotelluric exploration.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"134 ","pages":"Article 103506"},"PeriodicalIF":3.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}