Tectonophysics最新文献

{"title":"Applying and validating Coulomb rate-and-state seismicity models in acoustic emission experiments","authors":"Elías Rafn Heimisson ,&nbsp;Milad Naderloo ,&nbsp;Debanjan Chandra ,&nbsp;Auke Barnhoorn","doi":"10.1016/j.tecto.2024.230574","DOIUrl":"10.1016/j.tecto.2024.230574","url":null,"abstract":"<div><div>A central goal of laboratory seismology is to infer large-scale seismic processes from small-scale experiments, with acoustic emissions (AE) being a common observable. These signals, indicative of microfracturing, slip localization, and damage evolution, are often paralleled with earthquakes to understand seismic behaviors. This study challenges traditional perspectives by applying Coulomb rate-and-state seismicity theory, originally developed for earthquake clustering, to AE experiments. This theory maps stressing history to seismicity rates using rate-and-state friction, however, its validity under controlled experimental conditions remains an open question. We conducted four experiments on a sawcut sample of red felser sandstone, representing a fault under variable stress conditions. Adjustments in loading rates and initial conditions revealed that, while a single free parameter <span><math><mi>A</mi></math></span>—related to the direct effect—should suffice, a rescaling of the model by 1.5 to 2.2 was necessary for fitting the data. Differences in values across experiments appeared mostly non-systematic, and partial data usage did not yield consistently systematic parameter migrations. These findings suggest that fault microstructure may complexly alter parameter values during loading beyond what is accounted for in the Coulomb rate-and-state theory. Nonetheless, with the introduction of the scaling parameter, the Coulomb rate-and-state theory effectively captures the fundamental aspects of AE responses to complex controlled loading histories.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"895 ","pages":"Article 230574"},"PeriodicalIF":2.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Teleseismic evidence for structural heterogeneity in East Japan forearc from seafloor S-net data","authors":"Motoya Suzuki,&nbsp;Dapeng Zhao,&nbsp;Genti Toyokuni,&nbsp;Ryota Takagi","doi":"10.1016/j.tecto.2024.230579","DOIUrl":"10.1016/j.tecto.2024.230579","url":null,"abstract":"<div><div>We measure and analyze 4381 P-wave and 4307 S-wave arrival times of 48 teleseismic events recorded at 150 stations of a permanent seafloor seismic network (S-net) installed in the outer-rise and forearc region off East Japan. The obtained relative travel-time residuals amounting to ∼3 s at the S-net stations are generally negative on the incoming Pacific and Philippine Sea plates and positive on the continental Okhotsk plate, which reflect high and low seismic velocities, respectively. This pattern is generally consistent with previous results on the seismic velocity structure of the crust and upper mantle beneath the East Japan forearc and the outer-rise area. Large early arrivals (∼2.0 s) appear in the southern part of the S-net for the teleseismic events in the southwestern direction, which are mainly due to southwestward steepening of the subducting Pacific slab beneath Kanto. In the study region, the Pacific slab is the most significant anomaly with a thickness of ∼90 km and a seismic velocity of 5–6 % higher than that of the surrounding mantle. Early arrivals (∼1.5 s) also appear at the S-net stations off South Hokkaido, which are caused by northwestward steepening of the Pacific slab beneath the Tohoku-Hokkaido junction area. These results shed new light on the structural heterogeneity and subduction dynamics of the East Japan arc.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"895 ","pages":"Article 230579"},"PeriodicalIF":2.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Moment tensors for small earthquakes and the stress regime in the mid-Atlantic United States","authors":"Kyle Homman,&nbsp;Andrew Nyblade","doi":"10.1016/j.tecto.2024.230582","DOIUrl":"10.1016/j.tecto.2024.230582","url":null,"abstract":"<div><div>Focal mechanisms for small magnitude earthquakes (M ∼ 1.3–4.1) in the mid-Atlantic region of the United States have been determined using a double-couple moment tensor inversion procedure. The 26 new focal mechanisms obtained, when combined with previously published mechanisms, show a pattern of reverse faulting in the easternmost portion of the study area and strike-slip faulting in the west, consistent with previous studies. The change in focal mechanisms from east to west helps to constrain the geographic location of the east-west transition in the stress regime to a NE-SW area within central Pennsylvania within proximity of the Allegheny Front. Stress inversions performed to constrain variations in the stress state across the region show that the maximum compressive stress varies only slightly, but that the near-vertical stress is the minimum compressive stress in the east and transitions to the intermediate compressive stress in the west, as expected for an east-west transition in reverse to strike-slip faulting. Analysis of driving forces causing the stress change suggests that tectonic terrane structure, glacial isostatic adjustment, and changes in gravitational potential energy have little effect on the stress field in this region, leaving the interaction of sublithospheric mantle flow with the eastern edge of the Laurentian cratonic lithosphere beneath central Pennsylvania as a primary explanation. The cratonic lithospheric keel may cause a deflection in mantle flow, thereby changing the stress field enough so that the magnitude of the vertical stress in relation to the minimum horizontal stress results in strike-slip as opposed to reverse faulting.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"895 ","pages":"Article 230582"},"PeriodicalIF":2.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788826","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":"Numerical modelling of lithosphere-asthenosphere interaction and intraplate deformation in the Gulf of Guinea","authors":"Jaime Almeida ,&nbsp;Hamzeh Mohammadigheymasi ,&nbsp;Marta Neres ,&nbsp;Stéphanie Dumont","doi":"10.1016/j.tecto.2024.230581","DOIUrl":"10.1016/j.tecto.2024.230581","url":null,"abstract":"<div><div>To present day, the phenomenon of intraplate deformation and its associated earthquakes remain elusive. In this work, we argue that intraplate deformation may result from the interaction between lithospheric and upper mantle dynamic processes. To this extent, we targeted the Gulf of Guinea and adjacent Western Africa, a region with both low plate velocities and clear asthenosphere dynamics, allowing us to isolate the individual underlying dynamic constraints which govern intraplate deformation. Thus, here we present 3D numerical geodynamic models of the asthenosphere-lithosphere interaction in the Gulf of Guinea, ran with the state-of-the-art modelling code LaMEM. We employ different initial/boundary conditions such as: (a) identical vs different spreading rates for the varying segments of the Atlantic mid-ocean ridge, (b) the presence/absence of weak zones (e.g., the Romanche/Central-African shear zones), and (c) the effect exerted by an active mantle plume, with a varying ascension velocity. Seismicity patterns was used to evaluate the models and their validity. Our results suggest that intraplate deformation within the Gulf of Guinea is influenced by the spreading rate of the mid-ocean ridge, with stress being localized around the ocean-continent transition and existing shear zones. They also suggest that the existence of an underlying stress source (e.g., a mantle plume) beneath the Cameroon region is crucial to explain the epicenter distribution/deformation in the region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"895 ","pages":"Article 230581"},"PeriodicalIF":2.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Slip instability of dilatant and fluid-saturated faults","authors":"Cheng Mei","doi":"10.1016/j.tecto.2024.230598","DOIUrl":"10.1016/j.tecto.2024.230598","url":null,"abstract":"<div><div>The mechanisms of slip instabilities of dilatant and fluid-saturated faults remain controversial, particularly in low-permeability environments. Using a rate and state friction model including the effects of dilatancy, we conduct a linearized stability analysis of a one-dimensional spring-slider model and reexamine the critical stiffness (<span><math><msub><mi>k</mi><mi>c</mi></msub></math></span>) of the fault zone as a function of fluid diffusivity and dilatancy factor. Our analytical results indicate that under fully-drained conditions, <span><math><msub><mi>k</mi><mi>c</mi></msub></math></span> is independent of dilatancy factor, while under poorly-drained conditions, <span><math><msub><mi>k</mi><mi>c</mi></msub></math></span> depends on dilatancy factor and fluid diffusivity. Both analytical and numerical results show that a non-negative <span><math><msub><mi>k</mi><mi>c</mi></msub></math></span> always exists, even for highly-dilatant and poorly-drained faults where <span><math><msub><mi>k</mi><mi>c</mi></msub></math></span> is proportional to fluid diffusivity. This implies that dilatancy does not alter the inherent (in)stability of fault slip, and that a sufficiently low system stiffness can always produce unstable fault slips without a critical pore pressure or critical dilatancy factor. These findings may provide new insights into effects of dilatancy on fault instability. The numerical results further illustrate that the fault slip acceleration tends to be significantly suppressed by increasing dilatancy factor and decreasing fluid diffusivity. These results may explain ubiquitous slow-slip events on natural faults that vary in length.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"895 ","pages":"Article 230598"},"PeriodicalIF":2.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788824","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":"Influence of seismometer misorientation on crustal thickness and Vp/Vs estimated with teleseismic P-wave receiver functions","authors":"Diogo Farrapo Albuquerque ,&nbsp;Marcelo Peres Rocha ,&nbsp;George Sand França ,&nbsp;Marcelo Bianchi ,&nbsp;Reinhardt A. Fuck","doi":"10.1016/j.tecto.2024.230577","DOIUrl":"10.1016/j.tecto.2024.230577","url":null,"abstract":"<div><div>We analyzed the influence of seismometer misorientation on crustal thickness and Vp/Vs estimated with teleseismic P-wave receiver functions simulating orientation errors during the rotation procedure of the horizontal components from true NS-EW (North-South, East-West) to RT (Radial-Tangential) coordinate system. During this procedure, we incrementally added 5° to the azimuth of the NS and EW components. The influence of the misorientation on P-wave teleseismic receiver functions was confirmed by the analysis of different parameters, such as normalized amplitude of P, Ps and multiple phases, reproduction of the radial component and crustal thickness and Vp/Vs estimates. This analysis indicated |45°| as the maximum misorientation allowed to consider crustal thickness, Vp/Vs, and geophysical interpretation reliable. For misorientations larger than |75°|, the reliability is low, and the data could be considered inappropriate for receiver function technique and crustal studies. We also identified some signs of misorientation: P-wave polarity inversion in radial RF trace combined with strong P-wave troughs in the tangential one, low Ps-wave normalized amplitude, reproduction of the radial lower than 90 % for most receiver function traces, and large standard deviations in crustal thickness and Vp/Vs estimates. Since most of the seismometers deployed at Brazilian Seismographic Network were well oriented (only three have orientation errors larger than 45°), in general, previous studies that used data from those stations for estimating crustal thickness and Vp/Vs using the H-k method are reliable. However, in future versions of Brazilian crustal models, the estimates using stations with misorientation larger than |45°| must be recalculated applying an azimuth correction. Finally, since normalized amplitudes are very sensitive to misorientation, the analysis of P and Ps amplitudes in radial receiver functions can be used as a tool to estimate seismometer orientation error and other issues affecting station gain.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"895 ","pages":"Article 230577"},"PeriodicalIF":2.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788827","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":"Seismotectonic assessment of the High Atlas orogen: Implications for the 8 September Mw 6.8 El-Haouz earthquake","authors":"Hamza Skikra ,&nbsp;Abdelali Fadil ,&nbsp;Youness Ouassanouan ,&nbsp;Khalid Lakhouidsi ,&nbsp;Abdelilah Tahayt ,&nbsp;Abderrahmane Soulaimani ,&nbsp;Lahcen El Moudnib","doi":"10.1016/j.tecto.2024.230573","DOIUrl":"10.1016/j.tecto.2024.230573","url":null,"abstract":"<div><div>The Moroccan High Atlas is a slowly deforming intracontinental orogenic belt, characterized by moderate and diffuse seismic activity. The 8 September 2023 Mw 6.8 El-Haouz earthquake, one of the most powerful quakes recorded in North Africa, has intensified investigations into the seismotectonics of the High Atlas. This study examines seismotectonic patterns in the High Atlas using seismological and geodetic data to better understand the mechanisms driving such seismic events. Seismological data indicate active shortening in the region, contributing to ongoing mountain building. Present-day deformation is partitioned between thrust and strike-slip faulting, with NW-SE compression, consistent with the broader stress field in North Africa. Frequency-magnitude distribution analysis indicates that the Western High Atlas exhibited low b-values, slightly lower than 1, in the eight years preceding the El-Haouz earthquake, with an low b-value (∼ 0.8 ± 0.1) near the epicenter, suggesting high stress accumulation in the region. GNSS observations reveal that the High Atlas experiences low geodetic velocities compared with the Rif collision belt, with displacements below 1 mm/year. Notably, the axial zone of the Western High Atlas exhibits an uplift of 1.1 mm/yr. The combination of moderate shortening and relatively higher uplift prior to the El-Haouz earthquake suggests that present-day deformation in the Western High Atlas is predominantly accommodated by the reactivation of inherited faults in the axial zone. This is further corroborated by the distribution of aftershocks, which supports a steeply dipping seismogenic fault manifested by the Tizi n'Test Fault.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"895 ","pages":"Article 230573"},"PeriodicalIF":2.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181957","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":"Intra-salt deformation of K-Mg salt layers in diapiric structures, an analogue modelling approach","authors":"Alexandre Pichat ,&nbsp;Naïm Célini ,&nbsp;Sylvie Schueller ,&nbsp;Jean-Marie Mengus ,&nbsp;Claude Gout ,&nbsp;Sabine Delahaye ,&nbsp;Jean-Paul Callot","doi":"10.1016/j.tecto.2025.230635","DOIUrl":"10.1016/j.tecto.2025.230635","url":null,"abstract":"<div><div>K-Mg salts are one to six orders of magnitude less viscous than halite and therefore flow faster than other evaporites. However, their influence and deformation patterns in diapiric structures are poorly understood. Analogue models are useful for simulating salt deformation, but have never been used to model heterogeneous salt formations involving low-viscosity K-Mg salts. We have developed a new material, designated Glime, which has a near-Newtonian behavior over the range of experimental strain rates, and a viscosity one to two orders of magnitude lower than that of the silicone putty. The Glime allowed us to simulate K-Mg salt layers interbedded with halite (represented by silicone) in analogue models of passive diapirs that were X-ray scanned. The results show that K-Mg salt absorbs more deformation than halite, forming intrasalt pillows in the early stages of diapiric growth. During diapir development, K-Mg salts are radially redistributed at the diapir apex and/or intruded by the lower salt units, leading to their verticalization along the diapir flanks. Shearing and rapid flow within verticalized K-Mg salts cause them to enlarge and form bulges at layer pinch-outs, above which vortex flows may also form. Verticalized K-Mg salts also act as shear zones promoting the rise of the lower salt layers. The results provide first-order guidelines for predicting intra-salt diapiric deformation involving K-Mg rich salts and call for further experiments to enhance our understanding. These findings are critical for anticipating the challenges of drilling within diapiric structures and optimizing the development of salt caverns for green hydrogen storage.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"898 ","pages":"Article 230635"},"PeriodicalIF":2.7,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Erratum to “Geophysically-BASED structural framework and tectonic evolution of the Brazilian equatorial margin” [Tectonophysics 896 (2025) /230604]","authors":"Francisco Gabriel Ferreira de Lima ,&nbsp;Walter Eugênio de Medeiros ,&nbsp;Emanuel Ferraz Jardim de Sá","doi":"10.1016/j.tecto.2025.230627","DOIUrl":"10.1016/j.tecto.2025.230627","url":null,"abstract":"","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"897 ","pages":"Article 230627"},"PeriodicalIF":2.7,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143142248","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":"Reactivation of critically-stressed basement faults and related induced seismicity in the southeastern Sichuan basin","authors":"Mengke An ,&nbsp;Rui Huang ,&nbsp;Derek Elsworth ,&nbsp;Fengshou Zhang ,&nbsp;Zhen-Yu Yin ,&nbsp;Liuke Huang ,&nbsp;Zhengyu Xu","doi":"10.1016/j.tecto.2025.230628","DOIUrl":"10.1016/j.tecto.2025.230628","url":null,"abstract":"<div><div>The southeastern Sichuan basin possesses abundant gas shale resources that are currently being recovered. The basement strata are seismically active making it important to understand the effect of fluid injection during geo-energy extraction and storage. We recovered outcropping basement rocks and conducted friction experiments on simulated rock gouge to assess the potential for frictional stability. Meanwhile, we also calculated the poroelastic Coulomb stresses resulting from fluid injection to define the impact of stress perturbations on fault stability. These results are combined with the seismic reflection images to analyze the seismic potential. Results indicate the basement rocks include clay-lean granites and sandstones and clay-rich slates; gouge frictional strength and stability are controlled by the clay contents. The gouge frictional strength monotonically decreases and fault stability is enhanced with increasing clay content. Poroelastic stresses induced by fluid injection can reactivate critically-stressed faults within 2 km of the injection site, but decay rapidly with increasing distance. The experimental-modelling results combined with seismic reflection profiles indicate that basement fault stability is controlled by various factors, including fault aseismic slip in the pressurized zones, poroelastic stress transfer from fluid injection and gouge mineralogy. These results have important implications for understanding instability of basement faults induced by fluid injection during energy extraction and storage and contribute to reducing seismic hazard in the southeastern Sichuan basin.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"898 ","pages":"Article 230628"},"PeriodicalIF":2.7,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031476","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}