Journal of Geophysical Research: Solid Earth最新文献

{"title":"Surface Deformation of the Nanga Parbat Crustal Diapir in the Northwestern Himalaya Imaged With GNSS and InSAR","authors":"Pauline Meyer, François Jouanne, Marie-Pierre Doin, Owais Ahmed, Adnan Alam Awan, Naveed Munawar, Ghulam Akbar","doi":"10.1029/2025jb032286","DOIUrl":"https://doi.org/10.1029/2025jb032286","url":null,"abstract":"The Nanga Parbat–Haramosh Massif located in the northwestern syntaxis of the Himalaya is an antiformal structure considered as a crustal diapir undergoing exhumation at a rate larger than 10 mm/yr since 1 Ma. Using GNSS horizontal surface velocities and a vertical and east–west decomposition of the Sentinel-1 interferometric line-of-sight velocities, we quantify the present-day ground deformation of this massif. Based on these velocity fields, the surrounding Plateaus appear stable, exhibiting only surficial downslope movements likely related to rock glacier or permafrost deformation. The Nanga Parbat massif is dominated by uplift reaching up to 6 mm/yr but also shows an asymmetry of the horizontal displacement across the massif. South of latitude 35.3°N, the massif is characterized by uplift only whereas, between latitudes 35.3°N and 35.7°N, the western part of the massif exhibits westward displacement along a major thrust while the eastern part is only affected by vertical displacement. At last, the northern part of the massif seems to be affected by uplift but also by significant southward displacement. The InSAR velocity profiles reveals the presence of normal faults with no preferential dipping direction located in the extension side (<i>extrados</i>) of the crustal fold that are accommodating local extension. The inversion of co-seismic InSAR displacements shows that they are related to slip on a fault with geometry compatible with the focal mechanism of a Mw 5.1 earthquake in 2019. Therefore, we suggest that the massif consists of a ductile core undergoing vertical flow, overlain by a brittle carapace affected by active faulting.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"17 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147726460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uplift History of the Southeastern Tibetan Plateau Revealed by Coupled Surface Processes and Orographic Precipitation Model","authors":"Fan Zhang,&nbsp;Xiaoping Yuan,&nbsp;Yuqiang Li,&nbsp;Xiaoming Shen,&nbsp;Jing Liu-Zeng","doi":"10.1029/2026JB033995","DOIUrl":"10.1029/2026JB033995","url":null,"abstract":"<p>The southeastern Tibetan Plateau (SETP) has long been a key region for studying tectonic processes and landscape evolution. However, major controversies remain over the extent of central Tibetan Plateau uplift since the India-Asia collision, the growth pattern of the SETP, and the roles of precipitation and tectonics on the SETP growth. Here, we use a landscape evolution model that couples surface processes and orographic precipitation to reproduce the landscape evolution of the SETP under changes in tectonic uplift and climate over time and space. We define two end-member scenarios: one in which the central Tibetan Plateau initially existed as a high-elevation plateau, and another in which it began at low elevations, with outward plateau growth prescribed in both. Our results show that, irrespective of the initial topographic condition of the central plateau, river-profile inversions consistently indicate that the eastward extent of uplift in the central plateau was limited to less than ∼400 km east of the source region of the Three Rivers. Further <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>χ</mi>\u0000 </mrow>\u0000 <annotation> $chi $</annotation>\u0000 </semantics></math>-elevation analysis of river profiles suggests that southeastward propagating uplift of the plateau likely initiated by at least the Oligocene. Furthermore, our surface process models, both with and without orographic precipitation, align with the observed topography, implying that orographic precipitation has a minimal impact on the landscape evolution of the SETP. Our study thus provides critical constraints on the tectonic and climatic drivers shaping the SETP.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 4","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147663981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Depth Profiling of Zircon Crystallization Histories: New Insights Into Himalayan Magmatic-Tectonic Evolution","authors":"Yao Wang,&nbsp;Ze Liu,&nbsp;Liang-Liang Zhang,&nbsp;Li Liu,&nbsp;Jesse Walters,&nbsp;Peter A. Cawood,&nbsp;Lei Yang,&nbsp;Qing Wang,&nbsp;Daniel F. Stockli,&nbsp;Di-Cheng Zhu","doi":"10.1029/2025JB033324","DOIUrl":"10.1029/2025JB033324","url":null,"abstract":"<p>Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has expanded in situ U-Pb geochronology. However, conventional circular or square ablation pits (&gt;15 μm) lack the resolution to resolve complex or narrow growth zones (&lt;5–15 μm). Depth profiling offers a unique solution by ablating through the surface of mineral grains, producing continuous, spatially resolved isotopic data. Current depth profiling analyses rely on manual, subjective identification of age signal plateaus, hindering efficiency and reproducibility. This study introduces the Automated Depth Profiling Technique (ADEPT), a quantitative workflow that includes data optimization, automated plateau segmentation, and rigorous screening to objectively identify growth zones and calculate U-Pb ages. Bayesian posterior validation of ADEPT showed &gt;84% of data within one root mean square error. Applying ADEPT to 4,615 Himalayan leucogranite zircon depth profiles reveals that 74% of grains preserve 2–4 distinct age signal plateaus, confirming major age peaks at 45 ± 2, 35 ± 3, 19 ± 4, and 9 ± 2 Ma. Analysis of zircon age continuity (ΔAge, the difference between core/or mantle and rim ages) reveals a systematic eastward decrease across the Himalayan orogen. We interpret this trend as a record of thermal longevity of magma reservoir tied to the regional tectonic regime. Specifically, compressional and cooler settings foster more continuous zircon growth (i.e., smaller ΔAge), whereas extensional and warmer settings produce relatively discontinuous growth (i.e., larger ΔAge). ADEPT provides a robust and efficient tool for resolving complex mineral age histories and offers new insights into the magmatic and tectonic evolution of the Himalaya.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 4","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147663980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematics of Burial Remagnetizations in Fold-and-Thrust Belts: A Case Study From the South Pyrenean Foreland Basin (NE Spain)","authors":"P. Calvín,&nbsp;E. Izquierdo-Llavall,&nbsp;P. Sierra-Campos,&nbsp;E. Beamud,&nbsp;M. J. Dekkers,&nbsp;R. Egli,&nbsp;A. Rodríguez-Pintó,&nbsp;J. C. Larrasoaña,&nbsp;E. L. Pueyo","doi":"10.1029/2025JB033544","DOIUrl":"10.1029/2025JB033544","url":null,"abstract":"<p>This study investigates two burial-related remagnetizations in the Jaca–Pamplona foreland basin (Southern Pyrenees): one with dual polarity and a positive reversals test, and another with only reverse polarity. These components, labeled C3 and C4 based on their mean unblocking temperatures, were identified from a paleomagnetic analysis of 142 sites in Eocene turbidites of the Hecho Group. Component C3 shows unblocking temperatures of 250°C–350°C, systematic reverse polarity, and a predominantly post-folding timing. Component C4 exhibits unblocking temperatures of 250°C–550°C, dual polarity and a mainly syn-to postfolding acquisition. The spatial distribution of C4 polarity defines WNW–ESE bands parallel to structures and younging southward. The acquisition of C4 is interpreted as a chemical remagnetization triggered by progressive burial driven by combined sedimentary and tectonic loading that increased temperatures (up to ∼250°C in the deeper northern sectors, according to previous paleotemperature studies). This thermal evolution promoted authigenic, stable single-domain magnetite growth, beginning during the Lutetian (chron C20) and probably ending in the Rupelian (chrons C11-C10) as uplift and exhumation progressed. In contrast, the reverse polarity and post-folding behavior of component C3 suggest a mixed origin involving both chemical remagnetization and a thermoviscous overprint during the long chron C12r (Rupelian), contemporaneous with the youngest reverse C4 band and preceding the final exhumation of the basin. These findings highlight the complex interplay among tectonics, sedimentation, and chemical remagnetization processes in the South Pyrenean foreland, providing new insight into the timing and kinetics of remagnetization in fold-and-thrust belts.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 4","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB033544","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147666837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Microstructural Controls on Geothermal Reservoir Host Rock Responses to Elevated Pressures and Temperatures","authors":"V. Mura,&nbsp;J. Browning,&nbsp;G. Arancibia,&nbsp;D. Healy,&nbsp;N. Farrell,&nbsp;N. Bigaroni,&nbsp;C. Pineda,&nbsp;D. Morata,&nbsp;J. Mecklenburgh","doi":"10.1029/2025JB033327","DOIUrl":"10.1029/2025JB033327","url":null,"abstract":"<p>Rock microstructure controls geothermal fluid flow within reservoirs hosted in active volcanic environments and as such it is necessary to constrain the microstructural evolution of rocks at elevated pressure and temperature conditions. Despite Andean geothermal systems hosting numerous high enthalpy geothermal plays, there remains a paucity of experimentally derived seismic velocity and porosity data on rocks at crustal-relevant pressure conditions. Here, we provide novel constraints on the evolution of rock physical properties of five main representative lithologies of the Nevados de Chillán Geothermal System under dry conditions with confining pressures up to 120 MPa and following heat treatment up to 600°C. The variability of P-wave velocity changes with elevated confinement reveals the presence of both different densities of pre-existing cracks and different distributions of pore aspect ratios within the tested lithologies. Two target units, crystalline granodiorite and diorite, were further subjected to heat treatment to recreate potential temperature conditions within and around the geothermal reservoir. The heat treatment generated new populations of low aspect ratio cracks in both rocks, but this pore space was apparently more difficult to close in the diorite than in the granodiorite when resubjected to confinement. This difference is explained in a conceptual model whereby a combination of crack generation, realignment, and differences in crack geometry and distribution in the diorite relatively stiff microscale porosity that persists within the explored pressure range. These results provide laboratory-based constraints on the mechanical persistence of thermally induced damage in crystalline geothermal reservoir host rocks.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 4","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB033327","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147649325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Four-Dimensional Multiscale Global Subduction Models With Data Assimilation and Realistic Rheology","authors":"Xinyu Li, Lijun Liu, Zebin Cao, Yanchong Li","doi":"10.1029/2025jb032510","DOIUrl":"https://doi.org/10.1029/2025jb032510","url":null,"abstract":"The solid Earth is a complex system characterized by dynamic interactions among various tectonic components. Global mantle convection models equipped with data assimilation can effectively reproduce past subduction and associated mantle flow, providing a realistic framework for evaluating the intricate dynamic processes within the solid Earth. Despite recent advancements of data assimilation methods, their widespread application has been hindered by high computational costs due to the need for increasing model resolution and nonlinear rheology. Here, leveraging the mantle convection code ASPECT, we develop a multiscale global mantle convection model featuring adaptive data assimilation and employing nonlinear visco-plastic rheology. Our model successfully reproduces complex mantle evolution and structures, consistent with both observational constraints and previous model results. This represents the first published global mantle flow model built using ASPECT to achieve Earth-like subduction, with the aid of nonlinear rheology and adaptive data assimilation. Furthermore, the incorporation of adaptive mesh refinement and high-order finite element ensures high resolution and accuracy of model results. These advancements will contribute to a better understanding of plate tectonics and continental evolution.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"5 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147642159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Instability of Fluid-Mineral Equilibrium Under Non-Hydrostatic Stress Investigated With Molecular Dynamics","authors":"M. L. Mazzucchelli,&nbsp;E. Moulas,&nbsp;S. M. Schmalholz,&nbsp;B. J. P. Kaus,&nbsp;T. Speck","doi":"10.1029/2025JB033520","DOIUrl":"10.1029/2025JB033520","url":null,"abstract":"<p>Mechanical–chemical coupling governs the interaction between metamorphism and deformation and controls the long-term stability of subsurface reservoirs. Deformation induces non-hydrostatic stresses in minerals. However, the conditions for thermodynamic equilibrium between stressed solids and fluids remain debated. From a bulk thermodynamics perspective, Gibbs (1876, https://doi.org/10.5479/sil.421748.39088007099781) hypothesized that equilibrium under stress requires the accretion of a hydrostatic solid at the interface between the stressed solid and the fluid. Here, we use large-domain molecular dynamics (MD) simulations (up to 1 million particles) to test Gibbs's prediction by investigating the evolution of a stressed solid–fluid system toward equilibrium, without assuming non-hydrostatic thermodynamics. MD simulations reveal the spontaneous accretion of a low-stress solid rim at solid–fluid interfaces. This accretion evolves into surface instabilities (Asaro–Tiller–Grinfeld instabilities), where dislocations nucleate and relax the misfit strain between the stressed substrate and the accreting rim. These unstable interfaces have an analogous evolution as the surface instabilities observed in experiments of epitaxial growth and dissolution–precipitation under stress. Our results show that variation in the chemical potential of the solid component in the fluid depends on the entire stress state of the solid crystal, and that non-hydrostatic thermodynamic formulations based solely on the normal stress at interfaces do not predict rim accretion. Our results show that once a stable equilibrium is achieved, the thermodynamic equilibrium deviates only slightly from that of a purely hydrostatic system. These findings have important implications for pressure-solution processes and the mechanical–chemical evolution of stressed minerals and rocks.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 4","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB033520","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147641331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"The Effect of Temperature and Physical State of Water on the Frictional Properties of Chlorite-Altered Basaltic Gouges (Krafla Geothermal Field, Iceland)","authors":"W.-H. Wu,&nbsp;W. Feng,&nbsp;R. Gomila,&nbsp;T. Tesei,&nbsp;A. K. Mortensen,&nbsp;G. Di Toro","doi":"10.1029/2025JB032343","DOIUrl":"10.1029/2025JB032343","url":null,"abstract":"<p>Changes in the physical state of water may alter fault frictional properties in high-temperature geothermal systems, yet they have been little studied. Here, we perform slide-hold-slide experiments to examine the frictional properties (frictional strength <i>μ</i>_ss and frictional healing Δ<i>μ</i>) of chlorite-altered basalt from Krafla Geothermal Field under realistic hydrothermal conditions (temperature of 100–400°C and pore pressure of 3–30 MPa with water in liquid, vapor, and supercritical states). We show that (a) <i>μ</i>_ss is slightly larger in vapor (<i>μ</i>_ss ∼ 0.67–0.73) than in liquid and supercritical water (<i>μ</i>_ss ∼ 0.61–0.64); (b) Δ<i>μ</i> increases with both the logarithm of contact hold time and temperature; (c) stick-slip occurs at ≥300°C, and the stress drops are largest in vapor water. In the sheared gouges, slip zones are characterized by grain-size reduction of plagioclase and quartz due to cataclasis (≤300°C) and dissolution (400°C) without evidence of newly-formed minerals. The temperature-dependent Δ<i>μ</i> of gouges in the presence of liquid and supercritical water is promoted by the rearrangement of size-reduced grains and grain dissolution, while the large Δ<i>μ</i> in vapor water may result from the formation of interfacial chemical bonds between grains. Our results agree with the seismological observations in Krafla, where shallow faults cutting chlorite-altered basalts at temperatures &lt;200°C accommodate deformation mostly by aseismic slip (creep), while deeper faults are seismogenic at ≥300°C and in the presence of boiling fluids.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 4","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB032343","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147630722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"3D P-Wave Attenuation Tomography of the Tonga-Lau Subduction System With Improved Earthquake Source Parameters and a Transdimensional Bayesian Markov Chain Monte Carlo Approach","authors":"Yurong Riley Zhang,&nbsp;S. Shawn Wei,&nbsp;Joseph S. Byrnes,&nbsp;Dongdong Tian,&nbsp;Fan Wang,&nbsp;Maximiliano Bezada","doi":"10.1029/2025JB032176","DOIUrl":"10.1029/2025JB032176","url":null,"abstract":"&lt;p&gt;Seismic attenuation, resulting from anelasticity of Earth's materials, provides critical information on the thermal and compositional characteristics of Earth's interior. Accurately measuring the seismic wave energy loss during propagation and conducting seismic attenuation is challenging, as conventional methods for measuring attenuation suffer from the trade-offs between estimated source signature and along-path energy decay, and between damping and smoothing in linear tomography inversions. In this study, we first incorporate independently constrained source parameters to invert for path-average attenuation, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;t&lt;/mi&gt;\u0000 &lt;mo&gt;∗&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${t}^{ast }$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, thereby minimizing the trade-offs between path and source terms. Then, based on the refined &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;t&lt;/mi&gt;\u0000 &lt;mo&gt;∗&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${t}^{ast }$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; data set, we apply a transdimensional Bayesian Markov Chain Monte Carlo (MCMC) approach to image the 3D attenuation structure with robust uncertainty estimations. We apply these methods to a 1-year amphibious seismic array in the Tonga subduction zone and its adjacent Lau back-arc basin. The new &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;t&lt;/mi&gt;\u0000 &lt;mo&gt;∗&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${t}^{ast }$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; measurements fit the data well, and the new 3D tomography results reveal high P-wave attenuation anomalies in the Tonga-Lau mantle wedge with the highest attenuation of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;Q&lt;/mi&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.018&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mn&gt;0.002&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${Q}_{P}^{-1}=0.018,pm ,0.002$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; or &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Q&lt;/mi&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 ","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 4","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB032176","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147630723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Prolonged Hypocenter Migration in a Lower-Crustal Earthquake Swarm in Japan: Positive Feedback Between Heat Influx and Fluid Production","authors":"Junichi Nakajima, Kazuki Miyazaki, Nobuaki Suenaga, Shintaro Azuma, Shoichi Yoshioka","doi":"10.1029/2025jb032955","DOIUrl":"https://doi.org/10.1029/2025jb032955","url":null,"abstract":"The Yamaguchi earthquake swarm in western Japan occurred at unusually deep depths (25–40 km), well below the seismogenic zone, and exhibited prolonged zigzag hypocenter migrations over at least ∼180 days. Seismicity initiated in the southwestern part of the swarm area, followed by systematic migration eastward, northeastward, and northwestward. The swarm is confined in an area of ∼10 × 10 km, but a total distance of small-scale zigzag hypocenter migrations reaches ∼160 km in the period from February 1 to 31 July 2025, with an average velocity of ∼0.9 km/day. Spectral analyses indicate that low-frequency earthquakes are relatively enriched in low-frequency energy but form a continuum with regular earthquakes. Fifteen deep earthquakes occur in the early stage of the swarm activity at ∼72 km depth below the swarm area. We propose that high-temperature fluids ascending in the mantle wedge cause the deep earthquake cluster on their pathways, which eventually infiltrate pre-existing fault zones in the lower crust. Substantial heat flux, carried by high-temperature fluids and injected into the lower crust, induces dehydration of hydrous minerals along fault zones, supplying aqueous fluids, reducing the frictional strength, and triggering brittle failure even in the lower crust. We interpret that positive feedback between externally injected high-temperature fluids and internally produced aqueous fluids sustains long-term zigzag hypocenter migrations. These interpretations would highlight the potential role of high-temperature fluid migrations and resultant dehydration reactions along fault zones for triggering and sustaining lower-crustal earthquake swarms in regions normally dominated by ductile deformation.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"276 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147630726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}