Tectonophysics最新文献

{"title":"Characterising the 2025 Santorini–Amorgos seismic swarm: Implications of magmatic and tectonic processes","authors":"K. Lentas ,&nbsp;V.K. Karastathis ,&nbsp;F. Gkika ,&nbsp;E. Mouzakiotis ,&nbsp;P. Koutsovitis","doi":"10.1016/j.tecto.2026.231125","DOIUrl":"10.1016/j.tecto.2026.231125","url":null,"abstract":"<div><div>We investigate the source characteristics of the Santorini–Amorgos seismic sequence during its most active phase (late January to early March 2025) to constrain the processes driving the seismic outbreak and the interplay between tectonic stresses and magmatic/fluid activity. Probabilistic source inversions are carried out to estimate deviatoric and full (including non-deviatoric) moment tensors for a representative subset of earthquakes. Our findings suggest that approximately 65% of the examined earthquakes show pure double-couple, normal-faulting mechanisms, after taking into account the uncertainties in the computations due to errors in velocity models and hypocentres, based on realistic synthetic tests. Moreover, by examining the frequency content of the earthquake waveforms we confirm the volcano-tectonic characteristics of the seismic swarm. A stress inversion on the obtained moment tensors reveals principal stresses in agreement with the overall normal fault zones in the area and a rather low friction value, highlighting the significant involvement of tectonic component in the earthquake swarm, that was likely triggered by magma ascent within the crust and facilitated by the release of magmatic fluids, affecting the pre-existing fault system.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"926 ","pages":"Article 231125"},"PeriodicalIF":2.6,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153113","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":"2D gravity modelling in Central Italy: Clues for the seismogenesis in the Apennines","authors":"M.M. Tiberti ,&nbsp;M. Buttinelli ,&nbsp;F.E. Maesano ,&nbsp;F. Ferri ,&nbsp;P. De Gori ,&nbsp;L. Minelli ,&nbsp;M. Di Nezza ,&nbsp;C. D'Ambrogi","doi":"10.1016/j.tecto.2026.231113","DOIUrl":"10.1016/j.tecto.2026.231113","url":null,"abstract":"<div><div>In the Central Apennines (Italy), the most updated reliable 3D geological models of the crust in the area affected by the 2016–17 Amatrice-Visso-Norcia seismic sequence highlighted that the coseismic rupture at the surface can involve old inherited normal faults, while the seismogenic sources lay at depth, possibly reactivating and inverting previous thrust faults, as in the case of the Mw 6.5 Norcia earthquake (30 October 2016). Here, we present a 2D gravity model across the Central Apennines to complete and confirm the crustal geometries resulting from the 3D model itself. The cross-section was built by integrating different data types, including surface geology, hydrocarbon wells, seismic profiles, and results from receiver function analysis. It was then checked against gravity anomalies and the velocity distribution from Local Earthquake Tomography (LET), adding further details, and, finally, against seismicity recorded during the 2016–2017 sequence. The results substantiate the reliability of the geometries proposed in the RETRACE-3D model, as they fit well, except for some local misfits, with other independent data, such as the Bouguer anomalies and the velocity distribution from LET. Furthermore, integrating different data types allowed us to provide a detailed description of the structural setting of the Apennine chain and the surroundings of the RETRACE-3D study area and to identify some new features at seismogenic depths beyond those typically targeted in hydrocarbon exploration. In particular, we were able to investigate the nature of the basement top and its relationship with seismotectonics.</div></div><div><h3>Plain language summary</h3><div>Specific knowledge of the Earth's crust structures and our ability to image them in three dimensions are crucial for improving the understanding of the tectonic processes, particularly those responsible for generating earthquakes. The RETRACE-3D project produced a 3D model of the crust down to depths of 5–10 km in the area of the Central Apennines hit by the 2016–2017 seismic sequence. In this study, we analysed the gravity anomalies along a 2D cross-section to validate these results and to extend our knowledge to the surrounding areas and greater depths. Gravity anomalies make it possible to detect density variations within the crust, which can be related to the presence of specific geological units. Our analysis validated the RETRACE-3D project findings and provided insights into the nature of the upper crust at the base of the sedimentary succession. In particular, we identified an ancient (Permian-Triassic) sedimentary body, whose presence and current position appear to be closely related to the seismotectonics of the area.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"926 ","pages":"Article 231113"},"PeriodicalIF":2.6,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110631","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":"Deep multiparameter analysis of the precursory lithospheric, atmospheric and ionospheric anomalies before and during the 28 March 2025 Mw7.7 Myanmar-Burma earthquake","authors":"Angelo De Santis ,&nbsp;Xuemin Zhang ,&nbsp;Saioa A. Campuzano ,&nbsp;Pan Xiong ,&nbsp;Gianfranco Cianchini ,&nbsp;Jing Liu ,&nbsp;Serena D'Arcangelo ,&nbsp;Na Yang ,&nbsp;Mariagrazia De Caro ,&nbsp;Xinyan Ouyang ,&nbsp;Martina Orlando ,&nbsp;Maoning Feng ,&nbsp;Loredana Perrone ,&nbsp;Yongxian Zhang ,&nbsp;Dario Sabbagh ,&nbsp;Xinyi Jia ,&nbsp;Maurizio Soldani ,&nbsp;Hong Liu ,&nbsp;Ariana Varela-Mendez","doi":"10.1016/j.tecto.2026.231101","DOIUrl":"10.1016/j.tecto.2026.231101","url":null,"abstract":"<div><div>On March 28, 2025, at 06:20:52 UTC (12:50:52 LT), a catastrophic Mw 7.7 earthquake occurred in central Myanmar-Burma, marking one of the most devastating seismic events in recent history. The earthquake occurred along the Sagaing Fault (SF), a highly active right-lateral strike-slip fault that accommodates the northward motion of the Indian Plate relative to the Sunda Plate. A multiparametric approach has been applied in order to study the preparation phase of this great earthquake, analyzing data from ground, atmosphere and satellite, with a total of eleven kinds of potential earthquake precursors. The results show a sigmoid pattern of all anomalies before and during the earthquake occurrence, typical of a critical system approaching a critical point. The sequence of the anomalies and their space and time concentration support the lithosphere-atmosphere-ionosphere coupling (LAIC) model.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"926 ","pages":"Article 231101"},"PeriodicalIF":2.6,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089726","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":"Identification of the North Jining Basin Fault and its response to the northward expansion of the Shanxi rift system, North China","authors":"Zhikang Gong ,&nbsp;Dongli Zhang ,&nbsp;Weisheng Hou ,&nbsp;Ting Liu ,&nbsp;Jinhua Du ,&nbsp;Haoyu Zhou ,&nbsp;Zijian Feng ,&nbsp;Xin Sun ,&nbsp;Ruijie Xue ,&nbsp;Haiyun Bi ,&nbsp;Wenjun Zheng","doi":"10.1016/j.tecto.2026.231110","DOIUrl":"10.1016/j.tecto.2026.231110","url":null,"abstract":"<div><div>The northward growth and expansion of the Shanxi rift system (SRS) are key to understanding the geodynamic evolution of the northeastern Ordos block. Previous studies have suggested that Shanxi rift activity weakens north of the Daihai–Huangqihai Basin under the influence of the EW-strike Zhangjiakou–Bohai tectonic zone. In this study, remote sensing and field investigations reveal an ∼100 km long prominent linear structure north of the Jining Basin in the northeastern Ordos block. Three high-density electrical resistivity tomography (ERT) profiles across this structure identify this region as the North Jining Basin Fault, NE-striking, SW-dipping normal fault that structurally controls the northern margin of the basin, exhibiting typical fault depression characteristics and latest activity in the Holocene. Geological evidence confirms that the fault offsets mid-Holocene sediments with a vertical displacement of ∼2.7 m. Combined with the spatiotemporal evolution of the Shanxi rift system, these findings suggest that the northeastern boundary of the rift remains active and continues to propagate northward, with the North Jining Basin Fault representing northward expansion of the extensional regime of the Shanxi rift.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"926 ","pages":"Article 231110"},"PeriodicalIF":2.6,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-lived topography along rifted margins: Insights from Aparados da Serra escarpment, Southeast Brazil","authors":"Mauricio B. Haag ,&nbsp;Scott Jess ,&nbsp;Lindsay M. Schoenbohm ,&nbsp;Eva Enkelmann ,&nbsp;Taís F. Pinto","doi":"10.1016/j.tecto.2026.231100","DOIUrl":"10.1016/j.tecto.2026.231100","url":null,"abstract":"<div><div>The Brazilian margin is one of the longest elevated passive margins (EPMs) in the world. However, both the timing of uplift and the long-term evolution of this EPM remain highly debated. In this study, we present a new suite of apatite (U-Th-Sm)/He (AHe) and fission track (AFT) ages for the southern end of the Brazilian EPM, in the Aparados da Serra plateau. Combined with literature data, our results reveal that mean AHe ages range from 43 to 112 Ma, while AFT ages range from 46 to 222 Ma. Thermal history models suggest monotonic exhumation rates in the Aparados da Serra, with post-rifting rates &lt;50 m Myr⁻¹ in the coastal plain and &lt; 25 m Myr⁻¹ in the volcanic plateau. Collectively, our results imply a total erosion of 2–4 km of material from the coast and &lt; 2 km from the plateau since rifting ca. 120–100 Ma. AHe and AFT data indicate no detectable accelerated phase of exhumation during the Cenozoic, implying that recent uplift along the margin was either absent or minimal, and that the relief observed in the Aparados da Serra is likely a consequence of sustained rift topography. Based on the absence of major recent tectonic events, we argue that Cenozoic exhumation patterns in the Aparados da Serra were largely controlled by geomorphologic processes (e.g., differential erosion). Lastly, the equivalence between long (AFT and AHe) and short-term (catchment-averaged) erosion rates argues for sustained stability of the margin over geological timescales.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"925 ","pages":"Article 231100"},"PeriodicalIF":2.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033931","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":"Basin development and provenance of the Lower to Middle Jurassic Ban Don Group in Indochina: Implications for the Jurassic Palaeo-Pacific subduction and drainage patterns","authors":"James W. Handschy ,&nbsp;H. Tim Breitfeld ,&nbsp;Bui Huy Hoang ,&nbsp;Sarah W.M. George ,&nbsp;William J. Schmidt ,&nbsp;Juliane Hennig-Breitfeld ,&nbsp;Michael B.W. Fyhn ,&nbsp;Mette Olivarius ,&nbsp;Nguyen Quang Tuan ,&nbsp;Nguyen Thanh Tung ,&nbsp;Do Van Linh ,&nbsp;Dinh Quang Sang","doi":"10.1016/j.tecto.2026.231081","DOIUrl":"10.1016/j.tecto.2026.231081","url":null,"abstract":"<div><div>Reconstructions of the Mesozoic Palaeo-Pacific are contentious due to significant overprinting during Cenozoic tectonic reorganization in the South China Sea. Here we document rapid (c. 35 myr) basin development, infilling, and pervasive folding of the ∼4 km thick Ban Don Group, an Early to Middle Jurassic basin succession in south-central Vietnam. We address the tectonic significance of the Ban Don Group using sedimentary petrography, detrital zircon geochronology, and structural constraints. Petrography of sedimentary rocks of the Ban Don Group shows mixed recycled orogen character and volcanic arc provenance. Detrital zircon U-Pb geochronology supports sourcing from the Indochina cover units and basement blocks, such as the Kontum Massif, and importantly identifies Jurassic contemporaneous volcanic arc sources. Structural constraints require a phase of pervasive shortening shortly after deposition of the Ban Don Group. Together, these datasets, along with regional tectonic constraints suggest that the Ban Don Group was deposited along a convergent margin, interpreted here as back-arc basin during Early-Middle Jurassic subduction of the Palaeo-Pacific Plate under Indochina. Extension in the Indochina Block was likely a result of a change in the Palaeo-Pacific subduction angle. The NW basin axis of the Ban Don Group is compatible with Early to Middle Jurassic NW-directed back-arc extension and associated NW-dipping subduction. The symmetric shape and orientation of the Ban Don Group salient strongly supports NW Palaeo-Pacific Plate motion in the Late Jurassic. Therefore, NW-dipping subduction of the Palaeo-Pacific Plate during the Jurassic was the driving force for Ban Don Basin subsidence and subsequent shortening.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"925 ","pages":"Article 231081"},"PeriodicalIF":2.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995714","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":"Structural analysis and low-temperature thermochronology of the Ozbak-Kuh Mountains, Central Iran: Constraints on the influence of intraplate strike-slip faulting in the Arabia–Eurasia collision zone","authors":"Ali Ghiassi ,&nbsp;Ali Yassaghi ,&nbsp;Massimiliano Zattin ,&nbsp;Saeed Madanipour ,&nbsp;Reza Nozaem","doi":"10.1016/j.tecto.2026.231079","DOIUrl":"10.1016/j.tecto.2026.231079","url":null,"abstract":"<div><div>Intracontinental deformation in collision zones is generally localized along basement strike-slip fault zones, resulting in crustal shortening and fault-related exhumation of rocks. Strike-slip faulting plays a key role in accommodating crustal deformation in Central Iran, which is located within the active collision zone between the Arabian and Eurasian plates. This study investigates the impact of basement strike-slip faulting on intracontinental deformation of the Central Iran Microcontinent. These deformations are extensively localized in the Kashmar–Kerman Tectonic Zone (KKTZ). Previous U-Pb radiometric dating and thermochronometric studies from the southern parts of the zone have recorded predominantly Early Mesozoic events, whereas the northern parts document Cenozoic events. However, the central part of the zone, in the Ozbak-Kuh Mountains, has remained poorly constrained. Integration of new structural data with low-temperature thermochronometric data from the Ozbak-Kuh Mountains reveals two distinct cooling events. The first event, dated to the Late Cretaceous–Paleocene (∼55–75 Ma), coincided either with the initial closure of the Neo-Tethys Ocean and obduction of its ophiolites, or with the closure of a back-arc basin located to the north. In either scenario, the driving mechanism reflects a convergent tectonic setting characterized by folding of Paleozoic–Mesozoic rocks and deposition of the unconformable Paleocene Kerman Conglomerate. The second cooling event, which occurred during the late Eocene–Oligocene (∼27–37 Ma), is interpreted to mark the onset of continental–continental collision between the Arabian and Eurasian plates, as evidenced by the development of an angular unconformity between Oligocene–Miocene strata and older rock units. This event also led to transpressional deformation along the Kalmard Fault Zone (KFZ). Accelerated cooling in the western parts of the Ozbak-Kuh Mountains, as indicated by apatite fission-track (AFT) data, highlights the significant role of strike-slip faulting in accommodating oblique convergence.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"925 ","pages":"Article 231079"},"PeriodicalIF":2.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145957001","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":"Plate motion drivers: Geodynamical framework and statistical appraisal for the case of the Neogene Nazca–South America convergence","authors":"Valentina Espinoza ,&nbsp;Juan Martin de Blas ,&nbsp;Ingo L. Stotz ,&nbsp;Andrés Tassara Oddo ,&nbsp;Giampiero Iaffaldano","doi":"10.1016/j.tecto.2026.231095","DOIUrl":"10.1016/j.tecto.2026.231095","url":null,"abstract":"<div><div>Recent high-resolution reconstructions of plate motions reveal a complex history of alternating slowdowns and speedups, often over short timescales (<span><math><mo>&lt;</mo></math></span>5 Myr). These rapid changes offer an opportunity to reassess the geodynamic processes driving tectonic plates, which we explore using an analytical inverse framework. This approach, however, inevitably yields non-unique solutions when inferring the forces behind a motion change. We partly address this issue by focusing on forces capable of varying at rates consistent with rapid kinematic shifts, though the specific driver behind any change may remain ambiguous. We adopt a two-step methodology, using torque changes as intermediaries linking force variations to reconstructed absolute plate-motion changes. First, we employ an established method that combines rheological constraints with torque-balance principles to estimate the torque variation required for a given kinematic change. Second, we estimate torque-change vectors arising from a broad range of geodynamic scenarios — acting at plate boundaries (e.g., slab pull, interplate friction) and at the base of plates (e.g., asthenospheric flow). We then apply directional statistics to quantify the similarity between the motion-based torque-change distribution and each simulated vector. This comparison allows us to identify the location and direction of the force-change vectors most likely to produce the motion change of study. We apply this method to the Neogene Nazca–South America convergence. Our kinematic analysis reveals rapid slowdowns in the absolute motion of both plates and a pronounced Nazca speedup at <span><math><mo>∼</mo></math></span>10–12 Myr. Our geodynamic analysis indicates that the force variations driving the slowdowns are likely concentrated along the central segments of the shared convergent boundary. This result aligns with established hypotheses linking reduced convergence to Central Andes orogeny, thereby supporting our approach. Key advantages of this novel method include fast computation, explicit treatment of kinematic uncertainties, and broad applicability across tectonic settings.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"924 ","pages":"Article 231095"},"PeriodicalIF":2.6,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995715","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":"The Hainan plume and the origin of tectonic and magmatic activity in Southeast Asia","authors":"Rupak Banerjee ,&nbsp;Chujie Liu ,&nbsp;Stephen P. Grand ,&nbsp;Eric Sandvol ,&nbsp;Supriyo Mitra ,&nbsp;Xiaofeng Liang ,&nbsp;Shengji Wei","doi":"10.1016/j.tecto.2026.231087","DOIUrl":"10.1016/j.tecto.2026.231087","url":null,"abstract":"<div><div>Southeast Asia hosts widespread Cenozoic intraplate volcanism that is not related to arc volcanism or to the opening of the South China Sea. In this study, we analyze the Southeast Asia portion of the recently developed full waveform seismic model, FWEA23, presenting its first comprehensive interpretation for this region. We observe slow shear velocity (Vs) anomalies (∼4–5%) extending to ∼660 km depth beneath Hainan island, resembling one or more plume-like upwellings. At depths &lt;220 km, the slow anomaly extends westward to the Sagaing fault, eastward to the subduction zones, and northward to ∼26°N latitude. This lateral spreading explains the similarities in timing and geochemical signature between the Cenozoic intraplate volcanism and the Hainan volcano. We observe that the asthenospheric mantle (100–220 km) beneath Southeast Asia is ∼1.4% slower than the global average shear velocity of oceanic asthenosphere, implying that the mantle beneath Southeast Asia is warmer than the global adiabat. We also detect high Vs anomalies (up to ∼3%) in the mantle transition zone, resembling lithospheric slab fragments which trap heat and may have facilitated plume initiation through the slab gaps. Additionally, we present evidence from radial anisotropy (&gt; + 3%), which reveals strong horizontal mantle flow (&lt;200 km) away from the Hainan plume. This is consistent with lateral plume-head spreading, and associated lithospheric thinning across Southeast Asia. Our results provide new constraints on mantle dynamics of Southeast Asia by (i) highlighting the super-adiabatic character of the asthenosphere, (ii) a slab-induced mechanism for Hainan plume generation and (iii) the genesis of the intraplate volcanism.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"924 ","pages":"Article 231087"},"PeriodicalIF":2.6,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995810","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":"Multiscale fault complexity and hydrothermal processes drive earthquake swarms in the Tengchong Volcanic Field, Southeastern Tibetan Plateau","authors":"Jin-Zhi Ma ,&nbsp;Lingsen Meng ,&nbsp;Hao Yin ,&nbsp;Yiming Bai ,&nbsp;Zekun Li ,&nbsp;Yinshuang Ai","doi":"10.1016/j.tecto.2026.231080","DOIUrl":"10.1016/j.tecto.2026.231080","url":null,"abstract":"<div><div>Situated in the southeastern Tibetan Plateau, the Tengchong volcanic region is characterized by elevated surface heat flow and serves as a natural laboratory for investigating fluid-induced seismicity within structurally complex fault systems. Using a dense 12-month broadband seismic dataset, we construct a high-resolution earthquake catalog and identify three distinct seismic swarms. These swarms extend beyond classical stepovers, involving diverse fault structures such as conjugate systems and sharply curved fault bends. All occur along pre-existing faults, with two located to the east and southeast of the main Tengchong volcanic zone, in previously unstudied areas. This indicates that both the spatial distribution and evolution of swarm activity are strongly influenced by fault geometry. The swarms' spatiotemporal behavior is well described by a pore-pressure diffusion process, as evidenced by distinct migration fronts and back fronts, and correlated fluctuations in background seismicity rates. Notably, the swarms exhibit localized stress heterogeneity, likely driven by variations in excess pore-fluid pressure. In Swarm 3, a three-phase migration pattern and rupture orientations nearly perpendicular to the main fault trace further suggest that fault geometry and local stress heterogeneity play a dominant role in rupture behavior. Additionally, the lower b-values observed in Swarm 3 imply higher differential stress and a greater potential for moderate-to-large earthquakes. These observations indicate that swarm evolution in the Tengchong region is governed by a combination of pore-pressure diffusion, inherited fault structures, and stress field heterogeneity. Both the diffusion and the heterogeneous stress conditions are likely linked to elevated excess pore-fluid pressure.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"924 ","pages":"Article 231080"},"PeriodicalIF":2.6,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995718","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}