Tectonophysics最新文献

{"title":"Asperity dynamics and secondary damage development during the closure of a fracture in granite","authors":"Jessica McBeck ,&nbsp;Benoît Cordonnier ,&nbsp;François Renard","doi":"10.1016/j.tecto.2025.231044","DOIUrl":"10.1016/j.tecto.2025.231044","url":null,"abstract":"<div><div>The dynamics of asperities and the resulting real contact area play an important role in the evolving frictional strength of fault zones, particularly during the interseismic period. The aperture of fractures controls the ability of fluids to traverse meaningful distances in geologically and industrially relevant timescales. Here, we show the evolution of the real contact area and aperture at increasing normal load in a triaxial compression experiment with X-ray tomography on a Westerly granite rock core with a preexisting core-spanning fracture oriented perpendicular to the maximum compressive principal stress direction, at a confining pressure of 15 MPa and fluid pressure of water of 10 MPa. At the onset of normal loading, the real contact area increases linearly with the differential stress, at a rate of about 0.2 %/MPa until the real contact area is 20 %, mostly though the accumulation of greater numbers of individual contacts, consistent with elastic deformation. Then the real contact area increases more rapidly with load, with increasing areas of individual contacts, consistent with plastic deformation. The real contact area reaches maximum values of 35 %, and then declines with increasing loading as secondary axial fractures propagate from the large sub-horizontal fracture. The average mechanical aperture first declines rapidly with loading, reaches a minimum value of 13 μm, and then increases before failure as secondary axial fractures develop. The rough sub-horizontal fracture and secondary axial fractures produce a long-lived zone of elevated porosity, which is 4 % above the background porosity (1–2 %) just before failure. Thus, a closing rough fracture can provide a conduit for fluid flow due to non-zero aperture and the production of secondary damage.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231044"},"PeriodicalIF":2.6,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785278","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":"Insights into the 2021 Arkalochori (Crete Island, southern Greece) foreshock swarm through an enhanced deep-learning seismic catalog","authors":"Filippos Vallianatos ,&nbsp;Vasilis Kapetanidis ,&nbsp;Georgios Michas ,&nbsp;Andreas Karakonstantis","doi":"10.1016/j.tecto.2025.231045","DOIUrl":"10.1016/j.tecto.2025.231045","url":null,"abstract":"<div><div>On 27 September 2021, a damaging earthquake of <em>M</em>_w6.0 struck central Crete (Greece), close to Arkalochori village; the strongest earthquake ever recorded in this area during the instrumental period. Remarkably, the mainshock was preceded by an intense foreshock swarm that lasted almost four months. However, the lack of local seismological stations severely limited the event-detection capability of conventional methods, rendering an in-depth analysis of the foreshocks' evolution and statistical properties unfeasible. To enrich the seismic catalog, we employed a deep-learning model to detect and pick additional seismic phases automatically. A Bayesian Gaussian Mixture Model was then applied to associate the acquired P- and S-wave picks with specific event origins, followed by single-event location with a local 1D velocity model and double-difference relocation. A new, deep-learning catalog was constructed, with about ten times more events than in the previously published seismic catalogs. The evolution of the swarm presented a complex spatiotemporal pattern, with patches activated at different times. A major <em>M</em>_w4.9 foreshock occurred on 24 July 2021, triggering its own sub-sequence. In addition, the <em>b</em>-value spatiotemporal variations were investigated as possible stress state indicators in the seismogenic area. The analysis revealed persistent lower <em>b</em>-values than the background during the foreshock swarm, with the lowest just before the occurrence of the major <em>M</em>_w4.9 foreshock. Furthermore, the <em>b</em>-values spatial distribution highlighted that both the <em>M</em>_w4.9 foreshock and the <em>M</em>_w6.0 mainshock occurred in low <em>b</em>-value zones, suggesting an increased likelihood of occurrence and a critical accumulation of stress in the epicentral areas of the strongest events.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231045"},"PeriodicalIF":2.6,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785281","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":"Distinct destruction mechanism in the North China Craton: Insight from high-resolution thermochemical structure","authors":"Xiaoyu Yang ,&nbsp;Yonghua Li ,&nbsp;Juan Carlos Afonso","doi":"10.1016/j.tecto.2025.231042","DOIUrl":"10.1016/j.tecto.2025.231042","url":null,"abstract":"<div><div>Despite numerous studies on the thinning and destruction of the lithospheric mantle root beneath the North China Craton (NCC), the mechanisms for modification from refractory mantle of ancient craton to the fertile one remains poorly understood due to insufficient information of deep thermochemical structure. We investigate the mantle compositional and thermal structure of the NCC by jointly inverting Rayleigh wave dispersion, geoid height, elevation and surface heat flow (SHF) using a probabilistic inversion. We image significant differences in the thermochemical structure of lithosphere in the different blocks of the NCC. The lithospheric structure of the western North China Craton (WNCC) is dominated by relatively thick lithospheric roots (&gt;150 km) and depleted composition (Mg# ∼90–92), supporting the idea of the core of the WNCC is well-preserved. We observe a relatively thinner lithosphere (&lt;100 km) and more fertile signature in the central and eastern NCC, confirming that these areas have undergone lithospheric thinning and modification. We reveal the distinct lithospheric composition in the central and eastern NCC, indicating the difference of mechanisms of lithospheric reactivation. The low Mg# (Mg# ∼88.5–90) of the lithospheric mantle beneath the eastern North China Craton (ENCC) imply that the cratonic root were delaminated and replaced by a new fertile mantle. The coexistence of depleted and fertile mantle (Mg# ∼88.5–91.5) beneath the central NCC, implying that the depleted cratonic mantle partially evolved to fertile one through injection of melts/fluids originating from the asthenospheric mantle.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231042"},"PeriodicalIF":2.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785279","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":"3D azimuthal anisotropy model reveals crust-mantle deformation in the northeastern Songpan-Ganzi Block and adjacent regions","authors":"Yue Chen ,&nbsp;Qianzong Bao ,&nbsp;Xiaofei Chen","doi":"10.1016/j.tecto.2025.231043","DOIUrl":"10.1016/j.tecto.2025.231043","url":null,"abstract":"<div><div>The northeastern Songpan-Ganzi Block (NE-SPGZ), as the leading edge of the Tibetan Plateau's eastward expansion, remains controversial in its crust-mantle deformation mechanisms. Using teleseismic and ambient noise surface wave dispersion data, we obtained the 3D shear wave velocity and azimuthal anisotropy structure from 5 to 110 km depths. The results show low-velocity anomalies in the upper mantle of the NE-SPGZ and the western Qinling Orogenic Belt (WQL), which may be related to the thermal erosion and localized upwelling of asthenosphere. In the NE-SPGZ, the crust exhibits dominant NW-oriented fast-axis direction consistent with the regional tectonic trend, indicating overall crustal shortening. However, the upper mantle shows NE-oriented fast-axis direction with increased amplitude of anisotropy. We suggest that the combined effect of the asthenospheric activity, northeastward plateau compression, and Sichuan Basin resistance may result in significant NE-directed deformation within the softened upper mantle. The lower crustal low-velocity zone in the NE-SPGZ, generated by felsic crustal deformation, exhibits lateral heterogeneity in its anisotropy. Therefore, we infer that this zone may buffer crust-mantle decoupling. In the WQL, the fast-axis direction is consistently and strongly NW-oriented from crust to upper mantle, revealing the vertically coherent deformation in its weakened lithosphere. Conversely, the central Qinling Orogenic Belt and northern Yangtze Block are characterized by high-velocity lithospheres with weak anisotropy, indicating stable tectonic features and being less directly affected by the plateau expansion. The differential responses of these lithospheric blocks to the eastward plateau expansion reflect complex deep dynamic processes in the region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231043"},"PeriodicalIF":2.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785282","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":"Stratigraphic and provenance analysis of the Alamor–Lancones Basin: Implications for the Cretaceous–Paleocene tectono–magmatic evolution of the northern Andean forearc system","authors":"Hugo Carrasco ,&nbsp;Cristian Vallejo ,&nbsp;Cristian Nuñez ,&nbsp;José Herrera ,&nbsp;Lily J. Jackson ,&nbsp;Brian K. Horton ,&nbsp;Tonny Thomsen ,&nbsp;Pieter Vermeesch ,&nbsp;Wilfried Winkler","doi":"10.1016/j.tecto.2025.231037","DOIUrl":"10.1016/j.tecto.2025.231037","url":null,"abstract":"<div><div>The Cretaceous–Paleocene Alamor–Lancones Basin is a well-preserved and long-lived forearc basin in southwestern Ecuador and northwestern Peru. It occupies a key morphotectonic region of the northern Andes, where the forearc transitions from continental basement in the south to accreted oceanic terranes in the north. This study investigates the stratigraphic evolution of the basin through provenance analysis of siliciclastic units and their response to fluctuating tectonic regimes that influenced the region. The oldest basin fill corresponds to the fluvial–alluvial Sábalos Formation, which unconformably overlies marine Paleozoic metasedimentary rocks of the El Tigre Unit. Whereas the lower Sábalos Formation was derived from exhuming crustal rocks, the upper levels record increasing input from coeval Aptian–early Albian volcanism. A shift to an extensional tectonic regime led to mid-Cretaceous lithospheric thinning, normal faulting, and submarine mafic volcanism of the continental Celica–Lancones Arc (∼105–91 Ma). Extension-related subsidence resulted in a transition to marine sedimentation, as recorded by the Puyango and Ciano formations during the middle Albian–Turonian. Following a Santonian compressional event (∼85 Ma), deep-marine deposition of the Zapotillo Group in the basin documents pre-, syn-, and post-accretion of the Caribbean Large Igneous Province (CLIP). Pre-accretional forearc sedimentation, as represented by the Santonian–late Campanian Chaquino and Tronco Quemado formations, records magmatic arc provenance with minor continental basement input. A latest Campanian–Maastrichtian shift to dominantly crustal provenance within the Mangahurco and Cañaveral formations provides evidence for exhumation of forearc basement rocks north of the basin in response to accretion of the CLIP at ∼75–70 Ma. Post-accretional accumulation of the Cazaderos and Casanga formations (∼66 Ma) recycled late Maastrichtian–Paleocene magmatic arc detritus from the emerging continental Sacapalca Arc. Overall, the evolution of the Alamor–Lancones Basin highlights how temporal shifts in the regional tectonic regime exerted first-order control on forearc deformation (basin subsidence and inversion), sediment provenance, and coeval arc magmatism, the latter also recorded by detrital zircon Th/U ratios.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231037"},"PeriodicalIF":2.6,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753516","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":"Segmented crustal magma reservoirs beneath the Kula Volcanic Province (Western Anatolia) revealed by 3D MT imaging","authors":"Özgür Karaoğlu ,&nbsp;Mehmet Emin Candansayar ,&nbsp;Özcan Özyıldırım ,&nbsp;Ahmet Yıldız ,&nbsp;Can Başaran ,&nbsp;İsmail Demirci ,&nbsp;Yıldırım Dilek","doi":"10.1016/j.tecto.2025.231040","DOIUrl":"10.1016/j.tecto.2025.231040","url":null,"abstract":"<div><div>The Kula Volcanic Province (KVP) in western Anatolia represents the youngest expression of intraplate volcanism within the Aegean extensional province. Yet, the geometry and depth of its magma storage system have remained poorly constrained. Here we present the first three-dimensional magnetotelluric (MT) inversion of the region, based on a dense dataset of 105 stations across ∼60 × 60 km². The results reveal a major mid-crustal reservoir, ∼75 × 20 km in extent and emplaced between 5 and 25 km depth, accompanied by several smaller chambers up to 12 km across. Diapir-like protrusions extend from these bodies to depths of ∼5 km, their NNW–SSE orientation closely aligned with the fault architecture of the Gediz Graben.</div><div>Resistivity values below 5 Ω.m correspond to melt fractions exceeding 6–8 %, providing robust geophysical evidence for significant partial melts in the mid-crust. Petrological constraints indicate primary melts originated from the asthenospheric mantle at 65–90 km depth, while the anomalies resolved here represent secondary crustal reservoirs where ascending basaltic magmas became trapped and stabilised. This dual structure—deep mantle melting coupled with mid-crustal storage—reconciles geochemical constraints with geophysical imaging and highlights the segmented nature of the system, in which one dominant reservoir is compartmentalised by regional fault networks into smaller magma bodies.</div><div>These findings provide the first direct evidence for fault-controlled magma storage beneath the KVP. The identification of shallow intrusions reaching ∼5 km depth explains the localisation of Holocene volcanism, including the ∼4.7 ka Çakallar eruption, and points to a latent volcanic hazard. Placed in a global context, the KVP demonstrates how asthenospheric upwelling, lithospheric thinning, and tectonic segmentation combine to generate compartmentalised magma systems in highly extended continental crust.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"920 ","pages":"Article 231040"},"PeriodicalIF":2.6,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753514","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":"Complex nature of the crustal anisotropy in the western margin of the Indian subcontinent and its geodynamic implications","authors":"Sowrav Saikia ,&nbsp;Rakesh Prajapat ,&nbsp;Sumer Chopra ,&nbsp;Santosh Kumar ,&nbsp;Vinay Kumar Dwivedi ,&nbsp;Vikas Kumar","doi":"10.1016/j.tecto.2025.231039","DOIUrl":"10.1016/j.tecto.2025.231039","url":null,"abstract":"<div><div>The intraplate Gujarat region has thick crust which is undergoing deformation. Although the deformation process in the region is evident in the surface geological process, understanding the deeper geodynamic mechanism requires geophysical investigations. The crustal anisotropy can throw light on the nature of deformation of the crust and its geodynamic implications on overall tectonics of the region. This present study analyze the spatio-temporal variations of crustal anisotropy using teleseismic earthquakes recorded at 56 permanent stations and 20 temporary stations of the Gujarat State seismic network. The primary findings of 1306 pairs of radial and tangential components Pms phase splitting shows spatial variations in fast directions, aligned with major tectonic features and rest of some are aligned with absolute plate motion of Indian plate. The strength of the anisotropy is found to be low to average (average δt ∼ 0.10–0.45 s), suggesting the low deformations of the crust. The measurements of crustal anisotropy parameters indicate that anisotropy is attributed to the localized active faults, rather than affected by lower crust materials or horizontal compressive stress orientation. From the aligned/parallel trends of fast polarization direction (FPDs) of crustal anisotropy with the strike of active faults, the structure induced anisotropy is the primary cause of crustal anisotropy in Gujarat intraplate region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"920 ","pages":"Article 231039"},"PeriodicalIF":2.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731864","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":"From fabric to process: An integrated study of deformed quartz-rich carbonates","authors":"Maria Eleni Taxopoulou ,&nbsp;Marine Lartigau ,&nbsp;Charles Aubourg ,&nbsp;Nicolas E. Beaudoin ,&nbsp;Elli-Maria Charalampidou ,&nbsp;Jean Paul Callot","doi":"10.1016/j.tecto.2025.231034","DOIUrl":"10.1016/j.tecto.2025.231034","url":null,"abstract":"<div><div>This study investigates the presence and nature of diffuse deformation in a low-porosity carbonate rock that underwent polyphase tectonics and contains a network of veins, tectonic stylolites, and deformation bands. By using a non-destructive methodology based on Electron Backscatter Diffraction, X-ray computed tomography, coupled with results from Anisotropy of Magnetic Susceptibility and the Fry technique, we examine the grain fabric and strain distribution within the rock. Our investigation reveals evidence of quartz reorientation with respect to the polyphase contractional history of the area. Several mechanisms of quartz reorientation were proposed, including rigid reorientation during rotation and diffusion-related processes. The coexistence of ductile and brittle deformation mechanisms in the carbonate matrix indicates a complex response to compaction which can be recorded by the matrix, but does not appear to have a direct effect on the actual amount of shortening, as this is predominantly affected by the deformation bands. Our findings highlight the complexity of strain accommodation, with diffuse deformation creating subtle variations in grain size, shape, and orientation within the carbonate matrix. The study enhances our understanding of deformation processes in poly-deformed carbonate rocks and provides valuable insights into the geological context of the studied locations, by using a novel technique that can be useful for gaining qualitative and quantitative information from the rock samples. However, linking specific reorientation mechanisms to individual tectonic events remains challenging due to the multifaceted nature of deformation processes operating over different magnitudes and timescales.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"923 ","pages":"Article 231034"},"PeriodicalIF":2.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731865","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":"Mechanism and Co-seismic effects of the 2023 herat earthquake sequence in Afghanistan based on InSAR","authors":"Yuchao Zhong ,&nbsp;Hua Gao ,&nbsp;Hui Lin ,&nbsp;Guangcai Feng","doi":"10.1016/j.tecto.2025.231038","DOIUrl":"10.1016/j.tecto.2025.231038","url":null,"abstract":"<div><div>The October 2023 Herat earthquake sequence in western Afghanistan, involving four Mw 6.3 events, ranks among the most catastrophic seismic crises in the region over the past two decades, resulting in over 2000 fatalities and widespread structural collapse. This study integrates radar remote sensing technologies to investigate the focal mechanism and co-seismic impacts of this sequence. Firstly, co-seismic deformation was extracted from Sentinel-1 SAR images using Differential Interferometric Synthetic Aperture Radar (DInSAR) method. Then the Okada model was employed to invert fault geometry parameters and slip distribution. Furthermore, multi-temporal InSAR coherence analysis was performed to assess building damage, with a focus in critical zones such as Herat City and proximal villages. For the first two Mw 6.3 events, the ascending and descending deformation data reveal maximum of 33 cm and 54 cm in LOS direction, respectively. For the latter two Mw 6.3 events, the maximum are 58 cm and 76 cm. Through slip inversion, two distinct asperities were identified for the first two Mw 6.3 events (at depths of 5 km and 6 km) and another two for the latter two Mw 6.3 events (at depths of 6 km and 7 km, respectively). Fault model suggests that a concealed north-dipping fault between the Hari Rud and Siakhubulak fault zones imposes significant Coulomb stress perturbations on adjacent fault systems. Coherence analysis mapped severe damage in 12 villages near the epicenter, while collapsed structures in Herat City showed characteristic coherence difference values of 0.2–0.4. This study delivers co-seismic data for the Herat earthquake sequence, highlighting the seismic hazard in the future, quantified coherence difference provides a rapid proxy method for post-disaster building damage assessment, contribute to reconstruction in northwestern Afghanistan.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"920 ","pages":"Article 231038"},"PeriodicalIF":2.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731866","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":"Characteristics and generation mechanisms of tremors across a mountain belt","authors":"Yi-Chu Hua ,&nbsp;Kate Huihsuan Chen ,&nbsp;Satoshi Ide ,&nbsp;Pei-Ying Patty Lin","doi":"10.1016/j.tecto.2025.231036","DOIUrl":"10.1016/j.tecto.2025.231036","url":null,"abstract":"<div><div>We analyze ∼7000 tectonic tremors recorded between 2012 and 2022 across five clusters along Taiwan's mountain belt at depths of 30–50 km, providing new insights into slow fault slip within an active continental collision zone. All clusters occur above the Moho, exhibit thrust-dominant focal mechanisms, and are distinct from crustal seismicity. Tidal sensitivity varies spatially, with Clusters 2–5, located in zones of active collision and subduction termination, showing strong modulation (α = 0.53–0.75), while Cluster 1, situated in a post-collisional extensional environment near the Okinawa Trough, exhibits weaker sensitivity (α ≈ 0.3). These variations correlate with differences in tidal stress amplitude and tectonic regime. Moment tensor inversions reveal consistent thrusting styles, but principal stress orientations vary with depth, with σ₁ rotating from vertical in the upper crust to horizontal at tremor depths. This supports a two-layer deformation model shaped by orogenic collapse and lower crustal convergence-parallel shear. Our findings demonstrate that tremor generation in Taiwan reflects evolving stress regimes, fluid-assisted weakening, and structural heterogeneity associated with the interplay of collision, subduction, and back-arc extension. Tremors thus serve as sensitive indicators of deep-seated tectonic processes in dynamically evolving mountain belts.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"920 ","pages":"Article 231036"},"PeriodicalIF":2.6,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145689915","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}