Journal of Geophysical Research: Solid Earth最新文献

{"title":"An Ensemble Deep Learning-Based Acoustic Emission Picking Model Reveals Migratory Foreshocks on Large-Scale Laboratory Fault","authors":"Dekang Li,&nbsp;Fan Xie,&nbsp;Qing-Yu Wang,&nbsp;Enrico Milanese,&nbsp;Junju Xie,&nbsp;Li Li","doi":"10.1029/2024JB029934","DOIUrl":"https://doi.org/10.1029/2024JB029934","url":null,"abstract":"<p>Acoustic emissions (AEs) occurring during the frictional stick-slip experiment are crucial for predicting fault failure and understanding the nucleation mechanism of laboratory-scale earthquakes. However, detecting and picking their primary arrival phase (P-phase) in a complete manner remains a challenging task, especially when processing large data sets from a multi-channel continuous AE recording system throughout the laboratory earthquake cycles. In this study, we propose an Ensemble Deep Learning (EDL)-based supervised model named “AEbagging,” which comprises two individual feature extraction Deep Neural Networks serving as an encoder, and an EDL-based decoder for laboratory earthquake detection and phase picking. We conduct biaxial stick-slip experiment on a 0.85 m saw-cut granodiorite fault. By applying our model to the eight stick-slip events, we demonstrate its powerful capability in event detection and phase-picking. With the stacked pre-seismic AE sequences from the model-generated AE catalogs, we not only observe a precursory decrease in the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>b</mi>\u0000 </mrow>\u0000 <annotation> $b$</annotation>\u0000 </semantics></math>-value but also a migratory foreshock process from the lower right segment of the fault toward the upper left end during the nucleation phase. We discuss the possibility that such migratory foreshock activities are related to stress heterogeneities induced by fault surface roughness. This work demonstrates that the AEbagging model not only contributes to a better understanding of the spatiotemporal evolution of seismicity during laboratory fault instability, but also has potential for broad application in disciplines ranging from engineering to geophysics.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647109","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":"Illuminating Structural Variability of the East Aleutian Plate Interface From Local and Teleseismic P-to-S Converted Waves","authors":"K. A. Daly,&nbsp;G. A. Abers,&nbsp;M. E. Mann,&nbsp;G. Pang,&nbsp;D. Kim","doi":"10.1029/2025JB031472","DOIUrl":"https://doi.org/10.1029/2025JB031472","url":null,"abstract":"<p>The upper few kilometers of subducting plates govern subduction zones. Direct seismic imaging shows a variety of features there depending on the imaging method used. We compare P-to-S mode conversions from the subducting plate interface from teleseismic earthquakes to those from local earthquakes. Seismic signals are examined from 33 seismometers in the Alaska Peninsula region, including several permanent and temporary stations. The timing of the P-to-S conversions from local arrivals (local PS; 1–20 Hz signals) convert off an interface on average 8 km shallower than the equivalent teleseismic mode conversion, (teleseismic Ps; 0.05–1 Hz signals). The consistent positive teleseismic conversion is interpreted as the oceanic Moho, placing the local-PS conversions near the slab surface. Using 2D full waveform modeling, we find that models with a thin low-velocity layer at the top of the subducting plate containing elongated scatterers are required to reconcile observations at both frequencies. Scattering at high frequencies can be explained by anastomosing shear zones juxtaposing highly variable lithologies along foliation that parallels the plate surface. Local PS timing shows that a low-velocity layer exists across most of the array with velocities increasing as depth increases, in a manner resembling progressive metamorphism; the base of this layer generates the most prominent teleseismic Ps conversion. What constitutes this layer changes with depth; the layer is likely the metamorphosing oceanic crust at &gt;40 km depth but shallower is better explained as a shear zone comprised of fluids, hydrous minerals, and/or metasediment.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647388","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":"Apulia–Microplate Motion Change Following the MW 6.4, 26 November 2019 Durrës, Albania Earthquake","authors":"Giampiero Iaffaldano","doi":"10.1029/2024JB029948","DOIUrl":"https://doi.org/10.1029/2024JB029948","url":null,"abstract":"<p>Plate motion steadiness during the earthquake cycle is a central tenet of the plate tectonic theory. The advent of geodesy in geosciences allows measuring plate motions over periods much shorter than such cycle, and thus permits testing the tenet above against observations. Here I focus on the Apulia microplate, a tectonic unit that buffers the Nubia/Eurasia convergence. On 26 November 2019, a <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>W</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${M}_{W}$</annotation>\u0000 </semantics></math> 6.4 earthquake occurred along the Apulia eastern margin, near the city of Durrës, Albania. I utilize publicly–available position time–series measured at sites within Apulia via the Global Navigation Satellite Systems to infer a temporal change of the whole–Apulia motion from before to after the earthquake. I calculate Euler vectors for the motion of Apulia relative to fixed Eurasia via the classical minimization of the sum of squared misfits. A comparison of Euler vectors and associated surface motions from before to after the earthquake illustrates a 20% speedup that is beyond the impact of data noise and uncertainties at the 95% confidence level virtually anywhere within Apulia, and seems compatible with the direction of coseismic stress drop upon Apulia implied by focal mechanism solutions. I use quantitative models to show that the torque–variation required upon Apulia to generate the observed speedup appears to be consistent with the torque–variation imparted to Apulia by the coseismic stress drop over the Durrës rupture area.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029948","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647113","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":"Strike-Slip Versus Extensional Tectonics at the Oceanographer Transform Fault, Mid-Atlantic Ridge at 35°N","authors":"Ingo Grevemeyer,&nbsp;Dietrich Lange,&nbsp;Ingo Klaucke,&nbsp;Lars H. Ruepke,&nbsp;Anouk Beniest,&nbsp;Laura Gómez de la Peña,&nbsp;Yu Ren,&nbsp;Christian Filbrandt,&nbsp;Helene-Sophie Hilbert,&nbsp;Yuhan Li,&nbsp;Louisa Murray-Bergquist,&nbsp;Katharina Unger Moreno,&nbsp;Thor Hansteen,&nbsp;Colin W. Devey","doi":"10.1029/2024JB030880","DOIUrl":"https://doi.org/10.1029/2024JB030880","url":null,"abstract":"<p>Oceanic transform faults and their fracture zones are among the most striking features of ocean basins. Plate tectonics describes them as strike-slip zones connecting mid-ocean ridge segments. Still, no generally accepted theory exists for the lateral strain partitioning resulting in the deep and wide transform valleys and extensively tectonized inside corners. Here, we present results from multibeam bathymetry and a micro-seismicity survey from the slow-slipping Oceanographer transform on the Mid-Atlantic Ridge near 35°N. Swath-mapping echosounder data reveal a segmented transform fault. Away from the ridge-transform intersections (RTI) and in the eastern half of the transform valley, micro-earthquakes recorded on ocean-bottom-seismometers focus along the observed fault strands. Approaching the RTI, however, many micro-earthquakes cut across the inside corner, while the active faults step toward the inside corner, paralleling the trend of the transform valley. Focal mechanisms point to extension in the inside corner region, while strike-slip deformation is only recorded at distances larger than 15 km and away from the RTIs. These observations support a scenario in which deformation beneath a right-angular ridge-transform boundary at the seafloor develops into an oblique shear zone at depth, causing crustal thinning and consequently forming transform valleys. Away from RTIs, seismicity is focused on a narrow and segmented strike-slip fault as predicted by plate tectonics. Oceanic transform faults are consequently not only strike-slip but are also shaped by extensional processes, arguing for a revision of the concept of conservative plate boundaries to account for their morphology, segmentation, and significant lateral differences in seismic behavior.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635438","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":"New Insights Into Western Antarctic Peninsula Magmatism From Joint Inversion of UAV Magnetic and Gravity Data","authors":"Tom A. Jordan,&nbsp;Maximilian Lowe,&nbsp;Teal R. Riley","doi":"10.1029/2024JB030909","DOIUrl":"https://doi.org/10.1029/2024JB030909","url":null,"abstract":"<p>The Antarctic Peninsula is a unique sector of the circum-Pacific continental margin arc where subduction ceased due to a series of ridge-trench collisions, preserving a relatively un-deformed magmatic arc. This region, therefore, has the potential to provide key insights into how subduction systems behave during their final stages. However, the remote nature of the region means that both geological and geophysical data coverage is often sparse, limiting the ability to interpret its tectonic evolution. Here we present a new analysis of gravity and magnetic data collected from a Windracers Ultra Uncrewed Aerial Vehicle (UAV). The survey targeted a 75 × 25 km region where the Antarctic Peninsula bends and magnetic signatures change, which has been attributed to the onshore influence of adjacent oceanic transform faults running approximately orthogonal to the Peninsula. Using joint inversion of magnetic and gravity data based on a “Variation of Information” approach, we show the region is dominated by two large intrusions, of likely granodiorite composition. Our data indicate little evidence for structural control on magma emplacement, however, coincident imagery suggests that after magma emplacement the region was subject to significant deformation approximately parallel to the Peninsula margin. We interpret these features in terms of the processes occurring as subduction ceased.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030909","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635439","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":"Ultralow Velocity Zones at the Core-Mantle Boundary Near the Caroline Hotspot","authors":"Jiewen Li,&nbsp;Dongdong Tian,&nbsp;Mingming Li,&nbsp;Daoyuan Sun,&nbsp;Zhu Mao,&nbsp;Vasilije V. Dobrosavljevic","doi":"10.1029/2024JB030763","DOIUrl":"https://doi.org/10.1029/2024JB030763","url":null,"abstract":"<p>Ultralow velocity zones (ULVZs) at the core-mantle boundary (CMB), especially beneath the surface hotspots, are essential for understanding the nature of mantle convection and thermochemical evolution in the deep Earth. Here, we utilize tangential S and ScS recordings at the F-net in Japan from deep earthquakes in the New Britain and Kermadec–Tonga subduction zones to investigate ULVZs at the CMB beneath regions near the Caroline hotspot. A signal-enhancement approach known as the Flip-Reverse-Stacking (FRS) method, which focuses on the precursor (SdS) and reverberation (ScScS) of the main ScS phase caused by the ULVZ, is applied to resolve the detailed ULVZ structures. Synthetics derived from 1-D low-velocity models are compared to observations to obtain the thickness and S-wave velocity reductions of low-velocity zones (LVZs) across our study regions. The results show that LVZs with complex topographic undulations are widely distributed at the CMB near the Caroline hotspot. In particular, robust ULVZs are detected both inside and at the western edges of the Pacific Large Low-Velocity Province (LLVP). Additionally, a local elevated thermal boundary layer within the Pacific LLVP, with a lateral extent of ∼240 × 120 km, is revealed by the large ScS-S differential travel time delays. These observations indicate significant local thermal and chemical variations at the base of the mantle, which are likely caused by internal convection within the Pacific LLVP.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635349","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":"A Stockwell-Bessel Transform Based Method for Extracting Broadband Dispersion Curve From Seismic Ambient Noise Data","authors":"Gongheng Zhang,&nbsp;Xiaofei Chen,&nbsp;Chunquan Yu,&nbsp;Xuping Feng,&nbsp;Qi Liu,&nbsp;Lina Gao,&nbsp;Weibin Song","doi":"10.1029/2024JB030311","DOIUrl":"https://doi.org/10.1029/2024JB030311","url":null,"abstract":"<p>Ambient noise tomography has been widely used to image subsurface velocity structures, with a critical step being the extraction of surface-wave dispersion curves from noise cross-correlation functions (NCFs). However, obtaining reliable broadband dispersion data, especially at low frequencies, remains challenging. In this study, we introduce a novel method for extracting surface-wave dispersion curves from NCFs of each station pair based on the Stockwell-Bessel (S-J) transform, which requires no parameter settings. Compared with conventional methods, the new method overcomes limitations imposed by the 2–3 wavelength station distance. Synthetic tests demonstrate that the new method can accurately extract Rayleigh wave dispersion curves, with a relative error of less than 1<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>%</mo>\u0000 </mrow>\u0000 <annotation> $%$</annotation>\u0000 </semantics></math>, even when the inter-station distance is as small as one wavelength. Field applications in Madagascar further confirm that the S-J transform produces more stable and broader-band dispersion curves than conventional methods, facilitating higher-resolution imaging of subsurface velocity structures. Moreover, this method allows for the extraction of multi-modal dispersion curves through the superposition of S-J spectra from multiple station pairs, offering a practical approach for deriving regionally averaged velocity structure.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144624404","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":"3D Model of the Shallow Crustal Density Distribution of the Krafla Volcanic System in Iceland","authors":"Ana Martinez-Garcia,&nbsp;Joachim Gottsmann,&nbsp;James Wookey,&nbsp;Alison Rust,&nbsp;Magnús T. Gudmundsson,&nbsp;Yan Lavallée","doi":"10.1029/2025JB031670","DOIUrl":"https://doi.org/10.1029/2025JB031670","url":null,"abstract":"<p>Krafla volcano, located in Iceland's North Volcanic Zone, has been extensively studied using static gravity surveys since 1975. This study integrates measurements acquired between 2022 and 2023 with legacy data to produce a new gravity map of the area. We produce gravity gradient maps to delineate shallow subsurface density features and invert them to develop a 3D density model that images key subsurface structures. The combined survey coverage, extending from Fremrinámar to the Þeistareykir Volcanic Systems, reveals a range of features with contrasting densities which reflect the tectonic and volcanic processes that have shaped the area. Denser materials are associated with mafic intrusions along the principal faults related to caldera-subsidence and ancillary faults within the caldera. In the Iceland Deep Drilling Project 1 (IDDP-1) area, located inside the caldera, we identify a positive density anomaly at depths corresponding to magma encountered during drilling at 2.1 km depth. Negative gravity anomalies, indicative of relatively low-density materials, are distributed within and outside the Krafla caldera. Within the caldera, these anomalies are interpreted as felsic intrusions and highly fractured geothermal zones. Beyond the caldera, a prominent negative density anomaly corresponds to the graben structure associated with the Húsavík-Flatey Fault. Although strong near-surface gravity anomalies and the spatial distribution of our gravity measurements limit the identification of deeper structures (&gt;5 km), this study offers valuable insights into the distribution of the magmatic system features, as well as large tectonic characteristics in the area. These insights improve our understanding of magmatic and tectonic processes, volcanic hazards, and the future development of geothermal production in the area.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB031670","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144624401","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":"Structure and Seismicity of the Dead Sea Fault and the Galilee Revealed by 3D Earthquake Tomography","authors":"G. Ben-Dor,&nbsp;I. Kurzon,&nbsp;E. Aizenshtat-Soffer,&nbsp;N. Wetzler,&nbsp;R. Weinberger,&nbsp;C. Tape,&nbsp;M. Tsesarsky","doi":"10.1029/2024JB030816","DOIUrl":"https://doi.org/10.1029/2024JB030816","url":null,"abstract":"<p>Strike-slip fault systems near regions of oblique tectonic convergence/divergence commonly develop bends, stepovers, and other complexities that control crustal deformation, stress localization, and associated geophysical processes. Here, we investigate the complex crustal structure of the strike-slip Dead Sea Fault (DSF) system and the Galilee, in an area bounded by the Lebanese Restraining Bend in the north and by the intraplate Carmel-Gilboa-Faria Fault (CGFF) system in the south. Using traveltime data from ∼1,500 local earthquakes (1.5 &lt; <i>M</i>_<i>W</i>), we present 3D velocity models for P-waves (<i>Vp</i>), S-waves (<i>Vs</i>), their ratio (<i>Vp/Vs</i>), and a catalog of relocated seismicity for this complex tectonic region. Along the DSF, shallow differences between a high-velocity western side and a low-velocity eastern side form a bimaterial fault interface. Within the CGFF system, major sedimentary basins exhibit lower velocities than the surrounding crust. In the northern Kinneret basin (the Sea of Galilee), elevated <i>Vp</i>/<i>Vs</i> values suggest significant rock damage, possibly due to intense seismic activity. Increased mean <i>Vp</i>/<i>Vs</i> values and seismic activity below 15 km depth indicate a transition zone, perhaps related to changes in crustal mechanical properties. Relocated seismicity is generally confined to vertical fault segments along the DSF, with activity alternating between the border faults of the system. Beneath the Kinneret basin, shallow seismicity delineates a high-angle, eastward-dipping fault surface on the western side, possibly forming part of a negative flower structure beneath the basin. These observations provide new insights into the crustal structure of this region, revealing key features related to the DSF and CGFF systems.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030816","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598269","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":"Characterizing the Atacama Segment of the Chile Subduction Margin (24°S–31°S) With >165,000 Earthquakes","authors":"Jannes Münchmeyer,&nbsp;Diego Molina-Ormazabal,&nbsp;David Marsan,&nbsp;Mickaël Langlais,&nbsp;Juan-Carlos Baez,&nbsp;Ben Heit,&nbsp;Diego González-Vidal,&nbsp;Marcos Moreno,&nbsp;Frederik Tilmann,&nbsp;Dietrich Lange,&nbsp;Anne Socquet","doi":"10.1029/2025JB031256","DOIUrl":"https://doi.org/10.1029/2025JB031256","url":null,"abstract":"<p>The Atacama segment in Northern Chile (24°S to 31°S) is a mature seismic gap with no major event (<i>M</i>_<i>w</i> ≥ 8) since 1922. In addition to regular seismicity, around the subducting Copiapó ridge, the region hosts seismic swarms, and shallow and deep slow slip events. To characterize the fine structure of this seismic gap and its seismic-aseismic interplay, we instrumented the region with almost 200 seismic and geodetic stations. Using machine learning, we derived a dense, high-resolution seismicity catalog, encompassing over 165,000 events with double-difference relocated hypocenters. Our catalog details the outer rise, interface, intraslab, crustal and mantle wedge seismicity. We infer a detailed slab geometry, showing that the flat slab is dipping toward the south with a narrower extent along dip. The slab geometry controls the intraslab seismicity, with cross-cutting activity in the region of highest bending and a downdip limit around 105 km slab depth. Our catalog exhibits significant seismicity in the mantle wedge upper corner between 28°S and 31°S, highlighting the brittle behavior of the cold nose. On the subduction interface, interplate locking controls the updip end of the seismicity, with seismicity extending closer to the trench in low-locking areas. On fine scales, resolved by relative uncertainties below 50 m, the subduction interface has a complex 3D structure, showing a fractal distribution of seismic patches down to a scale of tens of meters. Our results provide a holistic view of this complex subduction zone, while at the same time giving insights into fine-scale structures and processes.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JB031256","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606616","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}