Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods...Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods of the coal-bearing formations were determined,and the fault systems were divided.Combined with the coal seam thickness and actual gas indication in logging,the controls of fault systems in the rift basin on the spatial distribution of coal and the occurrence of coal-rock gas were identified.The results show that the Wangfu fault depression is an asymmetrical graben formed under the control of basement reactivated strike-slip T-rupture,and contains coal-bearing formations and five sub-types of fault systems under three types.The horizontal extension strength,vertical activity strength and tectono-sedimentary filling difference of basement faults control vertical stratigraphic sequences,accumulation intensity,and accumulation frequency of coal seam in rift basin.The structural transfer zone formed during the segmented reactivation and growth of the basement faults controls the injection location of steep slope exogenous clasts.The filling effect induced by igneous intrusion accelerates the sediment filling process in the rift lacustrine area.The structural transfer zone and igneous intrusion together determine the preferential accumulation location of coal seams in the plane.The faults reactivated at the basement and newly formed during the rifting phase serve as pathways connecting to the gas source,affecting the enrichment degree of coal-rock gas.The vertical sealing of the faults was evaluated by using shale smear factor(SSF),and the evaluation criterion was established.It is indicated that the SSF is below 1.1 in major coal areas,indicating favorable preservation conditions for coal-rock gas.Based on the influence factors such as fault activity,segmentation and sealing,the coal-rock gas accumulation model of rift basin was established.展开更多
Permanent-magnet synchronous machines(PMSMs)are widely used in robotics,rail transportation,and electric vehicles owing to their high power density,high efficiency,and high power factor.However,PMSMs often operate in ...Permanent-magnet synchronous machines(PMSMs)are widely used in robotics,rail transportation,and electric vehicles owing to their high power density,high efficiency,and high power factor.However,PMSMs often operate in harsh environments,where critical components such as windings and permanent magnets(PMs)are susceptible to failures.These faults can lead to a significant degradation in performance,posing substantial challenges to the reliable operation of PMSMs.This paper presents a comprehensive review of common fault types in PMSMs,along with their corresponding fault diagnosis and fault-tolerant control strategies.The underlying mechanisms of typical faults are systematically analyzed,followed by a detailed comparison of various diagnostic and fault-tolerant control methods to evaluate their respective advantages and limitations.Finally,the review concludes by identifying key research gaps in PMSM fault diagnosis and fault-tolerant control,while proposing potential future directions for advancing this field.展开更多
The isolated fracture-vug systems controlled by small-scale strike-slip faults within ultra-deep carbonate rocks of the Tarim Basin exhibit significant exploration potential.The study employs a novel training set inco...The isolated fracture-vug systems controlled by small-scale strike-slip faults within ultra-deep carbonate rocks of the Tarim Basin exhibit significant exploration potential.The study employs a novel training set incorporating innovative fault labels to train a U-Net-structured CNN model,enabling effective identification of small-scale strike-slip faults through seismic data interpretation.Based on the CNN faults,we analyze the distribution patterns of small-scale strike-slip faults.The small-scale strike-slip faults can be categorized into NNW-trending and NE-trending groups with strike lengths ranging 200–5000 m.The development intensity of small-scale strike-slip faults in the Lower Yingshan Member notably exceeds that in the Upper Member.The Lower and Upper Yingshan members are two distinct mechanical layers with contrasting brittleness characteristics,separated by a low-brittleness layer.The superior brittleness of the Lower Yingshan Member enhances the development intensity of small-scale strike-slip faults compared to the upper member,while the low-brittleness layer exerts restrictive effects on vertical fault propagation.Fracture-vug systems formed by interactions of two or more small-scale strike-slip faults demonstrate larger sizes than those controlled by individual faults.All fracture-vug system sizes show positive correlations with the vertical extents of associated small-scale strike-slip faults,particularly intersection and approaching fracture-vug systems exhibit accelerated size increases proportional to the vertical extents.展开更多
The three-dimensional(3D)geometry of a fault is a critical control on earthquake nucleation,dynamic rupture,stress triggering,and related seismic hazards.Therefore,a 3D model of an active fault can significantly impro...The three-dimensional(3D)geometry of a fault is a critical control on earthquake nucleation,dynamic rupture,stress triggering,and related seismic hazards.Therefore,a 3D model of an active fault can significantly improve our understanding of seismogenesis and our ability to evaluate seismic hazards.Utilising the SKUA GoCAD software,we constructed detailed seismic fault models for the 2021 M_(S)6.4 Yangbi earthquake in Yunnan,China,using two sets of relocated earthquake catalogs and focal mechanism solutions following a convenient 3D fault modeling workflow.Our analysis revealed a NW-striking main fault with a high-angle SW dip,accompanied by two branch faults.Interpretation of one dataset revealed a single NNW-striking branch fault SW of the main fault,whereas the other dataset indicated four steep NNE-striking segments with a left-echelon pattern.Additionally,a third ENE-striking short fault was identified NE of the main fault.In combination with the spatial distribution of pre-existing faults,our 3D fault models indicate that the Yangbi earthquake reactivated pre-existing NW-and NE-striking fault directions rather than the surface-exposed Weixi-Qiaohou-Weishan Fault zone.The occurrence of the Yangbi earthquake demonstrates that the reactivation of pre-existing faults away from active fault zones,through either cascade or conjugate rupture modes,can cause unexpected moderate-large earthquakes and severe disasters,necessitating attention in regions like southeast Xizang,which have complex fault systems.展开更多
This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hype...This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hypersonic vehicles.In order to increase the control amount,this online control legislation makes use of model predictive control(MPC)that is based on the concept of iterative learning control(ILC).By using offline data to decrease the linearized model’s faults,the strategy may effectively increase the robustness of the control system and guarantee that disturbances can be suppressed.An adaptive fault observer is created based on the suggested ILMPC approach in order to enhance overall fault tolerance by estimating and compensating for actuator disturbance and fault degree.During the derivation process,a linearized model of longitudinal dynamics is established.The suggested ILMPC approach is likely to be used in the design of hypersonic vehicle control systems since numerical simulations have demonstrated that it can decrease tracking error and speed up convergence when compared to the offline controller.展开更多
To accurately diagnosemisfire faults in automotive engines,we propose a Channel Attention Convolutional Model,specifically the Squeeze-and-Excitation Networks(SENET),for classifying engine vibration signals and precis...To accurately diagnosemisfire faults in automotive engines,we propose a Channel Attention Convolutional Model,specifically the Squeeze-and-Excitation Networks(SENET),for classifying engine vibration signals and precisely pinpointing misfire faults.In the experiment,we established a total of 11 distinct states,encompassing the engine’s normal state,single-cylinder misfire faults,and dual-cylinder misfire faults for different cylinders.Data collection was facilitated by a highly sensitive acceleration signal collector with a high sampling rate of 20,840Hz.The collected data were methodically divided into training and testing sets based on different experimental groups to ensure generalization and prevent overlap between the two sets.The results revealed that,with a vibration acceleration sequence of 1000 time steps(approximately 50 ms)as input,the SENET model achieved a misfire fault detection accuracy of 99.8%.For comparison,we also trained and tested several commonly used models,including Long Short-Term Memory(LSTM),Transformer,and Multi-Scale Residual Networks(MSRESNET),yielding accuracy rates of 84%,79%,and 95%,respectively.This underscores the superior accuracy of the SENET model in detecting engine misfire faults compared to other models.Furthermore,the F1 scores for each type of recognition in the SENET model surpassed 0.98,outperforming the baseline models.Our analysis indicated that the misclassified samples in the LSTM and Transformer models’predictions were primarily due to intra-class misidentifications between single-cylinder and dual-cylinder misfire scenarios.To delve deeper,we conducted a visual analysis of the features extracted by the LSTM and SENET models using T-distributed Stochastic Neighbor Embedding(T-SNE)technology.The findings revealed that,in the LSTMmodel,data points of the same type tended to cluster together with significant overlap.Conversely,in the SENET model,data points of various types were more widely and evenly dispersed,demonstrating its effectiveness in distinguishing between different fault types.展开更多
The Altyn Tagh fault zone(ATFZ),which defines the northern boundary of the Tibetan Plateau,is one of the most striking features related to the India/Eurasia collision.Concurrent with the strike-slip movement,vertical ...The Altyn Tagh fault zone(ATFZ),which defines the northern boundary of the Tibetan Plateau,is one of the most striking features related to the India/Eurasia collision.Concurrent with the strike-slip movement,vertical uplift,and topographic building have formed a~3000-4000 m height difference between the Tarim Basin(TB)in the north and the Tibetan Plateau in the south.However,the spatial uplift characteristics and mechanism have not been well understood,particularly in the Late Quaternary.This research presents a comprehensive geomorphic analysis to establish the Late Quaternary tectonic uplift pattern for the entire ATFZ.We statistically excluded climatic and lithological factors that provided prominence for tectonism;combined with leveling data,river incision rate,and seismicity data,we reveal the along-strike and across-fault vertical deformation variations.The spatial distribution of the integrated geomorphic index(IGI)suggests significant differences between the two sides of the ATFZ.The IGI values decrease with slip rates in the northwestern side of the ATF,whereas wave-like in the southeastern side.The significant along-strike deformation difference between the two sides of the ATFZ may cause by differential rheology.These findings are crucial for assessing regional seismic hazards and providing new independent data to understand the Late Quaternary deformation style of the northern boundary of the Tibetan Plateau.展开更多
Mountain front faults form the boundary between mountains and adjacent plains.These faults can propagate toward the plains and escalate the risk of seismic hazard for near cities.The North Tehran Fault(NTF)is a mounta...Mountain front faults form the boundary between mountains and adjacent plains.These faults can propagate toward the plains and escalate the risk of seismic hazard for near cities.The North Tehran Fault(NTF)is a mountain front fault bordering the Central Alborz with Tehran and Karaj plains.Structural and morphotectonic data from interpreted aerial photographs,satellite images,airborne geomagnetic data as well as field surveying have been used for detailed segmentation and evolution of the North Tehran Fault.This resulted in identification of the fault segments as the Niknamdeh,Darband,Darakeh-Garmdarreh,and Karaj from east to west.Active kinematics of these segments includes both thrusting and left-lateral components;but the dominant component is different among the segments.The Niknamdeh segment is connected to the Mosha Fault with a hard linkage,while its connection with the Darband segment is a widespread deformation zone.The connection zone between the Darband and Darakeh-Garmdarreh segments has the highest density of minor faults along the North Tehran Fault.The boundary of the Darakeh-Garmdarreh and Karaj segments is controlled by the F-3 transverse fault that has offset the NTF for~3 km right-laterally.The NTF has inverted from normal to dextral oblique fault in Miocene.The fault kinematics has changed from dextral to sinistral in Pliocene-Quaternary.Further regional oblique convergence resulted in minor fault reactivation such as relay ramp breaching faults,propagation of several footwall branches and hangingwall bypasses geometrical change of alluvial fans,and transfer of deformation front southwardly to the Tehran and Karaj plains.The findings of this paper are also applicable to other active oblique converging mountain fronts,inverted mountain front faults and the transition of deformation from these structures to the foreland basin.展开更多
Seismic data plays a pivotal role in fault detection,offering critical insights into subsurface structures and seismic hazards.Understanding fault detection from seismic data is essential for mitigating seismic risks ...Seismic data plays a pivotal role in fault detection,offering critical insights into subsurface structures and seismic hazards.Understanding fault detection from seismic data is essential for mitigating seismic risks and guiding land-use plans.This paper presents a comprehensive review of existing methodologies for fault detection,focusing on the application of Machine Learning(ML)and Deep Learning(DL)techniques to enhance accuracy and efficiency.Various ML and DL approaches are analyzed with respect to fault segmentation,adaptive learning,and fault detection models.These techniques,benchmarked against established seismic datasets,reveal significant improvements over classical methods in terms of accuracy and computational efficiency.Additionally,this review highlights emerging trends,including hybrid model applications and the integration of real-time data processing for seismic fault detection.By providing a detailed comparative analysis of current methodologies,this review aims to guide future research and foster advancements in the effectiveness and reliability of seismic studies.Ultimately,the study seeks to bridge the gap between theoretical investigations and practical implementations in fault detection.展开更多
0 INTRODUCTION Turkey is located at the intersection of the Eurasian,Anatolian,Arabian,and African tectonic plates.Due to the ongoing northward compression from the Arabian Plate,the Anatolian Plate is pushed westward...0 INTRODUCTION Turkey is located at the intersection of the Eurasian,Anatolian,Arabian,and African tectonic plates.Due to the ongoing northward compression from the Arabian Plate,the Anatolian Plate is pushed westward in a tectonic escape mechanism,leading to the formation of the North Anatolian fault zone(NAFZ)and the East Anatolian fault zone(EAFZ)(e.g.,Bayrak et al.,2015;Duman and Emre,2013;Reilinger et al.,2006).展开更多
The Songliao Basin in northeast China is one of the largest petroliferous basins worldwide,and features the T_(2)fault system,which consists of numerous minor extensional normal faults.This study combines high-resolut...The Songliao Basin in northeast China is one of the largest petroliferous basins worldwide,and features the T_(2)fault system,which consists of numerous minor extensional normal faults.This study combines high-resolution 3D seismic datasets to detail the characteristics of the T_(2)fault system,contributing two key findings:(1)The T_(2)faults are confirmed as polygonal fault systems,characterized by closely spaced,layer-bounded faults with small throws,high dip angles,and random orientations,forming intricate polygonal networks.(2)The study reveals the influence of tectonic stresses on the fault system,showing spatial variations across different tectonic units.In depressions,T_(2)faults exhibit short lengths,small throws,high density,and multiple directions.In contrast,in inverted anticline belts,they have longer lengths,bigger throws,higher density,and concordant orientations.These variations demonstrate the impact of tectonic inversion on the development of T_(2)faults.The significance of this research lies in presenting a typical polygonal fault system developed in a deep lake succession and was superposed the influence by regional tectonic stress coeval with its development.The new insights facilitate a reevaluation of the T_(2)fault system's role in hydrocarbon migration and accumulation within the Songliao Basin.展开更多
The largest Tan-Lu active fault system in northeastern Asia,spans approximately 3500 km in length and varies in width from 10 km to 200 km.In 1668,an earthquake with a magnitude of 8.5 occurred in Tancheng,causing the...The largest Tan-Lu active fault system in northeastern Asia,spans approximately 3500 km in length and varies in width from 10 km to 200 km.In 1668,an earthquake with a magnitude of 8.5 occurred in Tancheng,causing the loss of over 50000 lives.To constrain the timing and process of the Tan-Lu fault system on eastern Asian margin,this study presents the field mapping,thin section observation,geochronology,and microanalysis of Weiyuanpu-Yehe ductile shear zone(WYSZ)of the northern Tan-Lu fault system.Kinematic indicators and microstructures suggest a sense of sinistral strike-slip.The deformation temperature of the mylonite is mediate to high based on the quartz deformation,c-axis fabrics.The differential stress of the shear zone is 20‒40 MPa using quartz paleopiezometry.The dikes within the shear zone yielded zircon U-Pb ages of 165‒163 Ma.However,due to the ambiguous geological relationship between the dikes and shear zone,additional geochronology is warranted.Since the Mesozoic era,based on the exposure of mylonite and dikes,the upper crust has been extensively eroded,exposing the ductile shear zone.Moreover,the understanding of the geometry and process of pre-existing structures has fundamental implications for predicating the potential earthquakes for the Tan-Lu fault system.展开更多
Natural fractures controlled by faults in ultradeep carbonate strata play substantial roles as both fluid migration channels and storage spaces.However,characterizing the heterogeneous distribution of underground frac...Natural fractures controlled by faults in ultradeep carbonate strata play substantial roles as both fluid migration channels and storage spaces.However,characterizing the heterogeneous distribution of underground fractures within the complex three-dimensional geometry of strike-slip fault zones remains challenging.This study investigates the characteristics of natural fractures controlled by strike-slip faults in the fractured Middle and Lower Ordovician reservoirs of the central and northern Tarim Basin,China.Seismics,cores,and image logs were integrated to quantitatively analyze the intensity and dip angle of natural fractures and findings were verified using published sandbox simulations.The carbonate reservoir contains three main types of natural fractures:tectonic fractures,abnormal high-pressure-related fractures,and stylolites.Strike-slip faults control the distribution and characteristics of tectonic fractures across various scales.Generally,both fracture intensity and porosity exhibit a decreasing trend as the distance from the main fault surface increases.Compared with those in non-stepover zones along a strike-slip fault,natural fractures and faults in stepover zones are more developed along the fault strike,with significantly greater development intensity in central stepover regions than that at its two ends.Furthermore,strike-slip faults influence the dip angles of both natural fractures and secondary faults.The proportion of medium-to-low-dip angle fractures and faults in the stepover zone is greater than that in the non-stepover zone.Additionally,the proportion of medium-to low-dip angle fractures and faults in the middle of the stepover is greater than that at both ends.Therefore,strike-slip fault structures control the dip angle of natural fracture and the heterogeneity of secondary fault and fracture intensity.The linking damage zone in the stepover contains a larger volume of fractured rocks,making it a promising petroleum exploration target.The development of stepovers and the orientation of present-day in-situ stress substantially influence the productivity of fractured reservoirs controlled by strike-slip faults.The analysis in this study reveals that reservoir productivity increases as the angle between the strike-slip fault segment and the maximum horizontal principal stress decreases.This study provides valuable insights for quantitatively evaluating fracture heterogeneity in fractured reservoirs and establishing optimized selection criteria for favorable targets in fault-related fractured reservoirs.展开更多
The strike-slip fault system in the central Tarim Craton controls a complex petroleum system with estimated reserves exceeding 1×10^(9)t,the fault-related fractures are important for hydrocarbon accumulation.In t...The strike-slip fault system in the central Tarim Craton controls a complex petroleum system with estimated reserves exceeding 1×10^(9)t,the fault-related fractures are important for hydrocarbon accumulation.In this paper,the basic parameters such as density and width of fractures are counted and classified,and the effects of fractures on reservoirs are analyzed.The results show that:(1)Structural fractures and stylolite were widely developed in Halahatang area and experienced at least three stages of activity based on the infilling materials and crosscutting relationship.(2)Fracture density,width,aperture,and dip angle vary in different wells,but the relationship between the above parameters and the distance to the fault core indicates the fracture differences in the fault damage zone and further provides a method to divide the inner units in the fault damage zone.In addition,oil and gas wells with high production mainly concentrate in the inner unit.(3)The infilling materials and degree of fractures vary.Fractures formed in the early stage are more filled and less open,while the fractures formed in the late stage are relatively less filled and more open.(4)Fractures improve porosity to a certain extent but greatly increase permeability,especially in the inner zone of fault damage zone with large quantity,multiple inclinations,less filling and large width.These features contribute to the formation of a higher-quality reservoir,further improving oil and gas production.This paper provides a quantitative characterization method for the study of strike-slip fault-related fracture-caved reservoirs,and points out that fault damage zone,especially the inner zone of the fault damage zone,is the potential goal for oil and gas exploration.展开更多
Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the ...Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the continuous fault-tolerant control protocol via observer design is developed. In addition, it is strictly proved that the multi-agent system driven by the designed controllers can still achieve bipartite consensus tracking after faults occur.展开更多
Riedel shear system,which consists of some different oriented faults and derivative structures,is an important pattern of tectonic activity and stress regulation,which has been widely applied to the interpretation of ...Riedel shear system,which consists of some different oriented faults and derivative structures,is an important pattern of tectonic activity and stress regulation,which has been widely applied to the interpretation of intracontinental deformation.The Laolongwan Basin,located in the western Haiyuan fault zone at the northeastern Tibetan Plateau,is a key area to study the Cenozoic intracontinental deformation in the northeastern plateau,which formed a complex active fault system during the Cenozoic.However,the activity of these faults and their kinematic mechanism remain unclear.In this contribution,based on detailed structural interpretation of remote sensing image,field observations and OSL dating analysis,we propose a Riedel Shear model of active fault system in the Laolongwan Basin.Our observations show that this active fault system consist of four major faults,including the left strike-slip Hasi Shan fault and Zihong Shan fault with thrusting characteristics,the Southern Zihong Shan thrust fault and the Mijia Shan normal fault.The fault offset and OSL dating analyses suggest that the left-lateral slip rate of the Hasi Shan fault is~2.60-3.01 mm/a since ca.15 ka,whereas the Zihong Shan fault is~1.10-1.13 mm/a since ca.14 ka.Faultslip vectors analyses indicate that the active fault system related to the Riedel Shear in the Laolongwan Basin was controlled by the regional ENE-WSW compressive stress.This compression also caused the significant left-lateral strike-slip movement along the Haiyuan fault zone at the same time,which might result from the northeastward continuous expanding of the Tibetan Plateau during the Late Cenozoic.展开更多
Recent exploration has highlighted the critical role of strike-slip faults in shaping ultra-deep carbonate reservoirs in the Tarim Basin.This study integrates satellite imagery,UAV photogrammetry,outcrop surveys and m...Recent exploration has highlighted the critical role of strike-slip faults in shaping ultra-deep carbonate reservoirs in the Tarim Basin.This study integrates satellite imagery,UAV photogrammetry,outcrop surveys and microscopic analysis to investigate the architecture of these faults and their impact on reservoir petrophysical properties.The strike-slip faults exhibit cores consisting of calcite bands,fault breccias and fractures,while the damage zones are predominantly fractured.Thicker fault cores and fault zones are associated with more extensive reservoir development.Individual strike-slip fault zones are primarily characterized by two sets of fractures intersecting the fault at small angles.When two fault systems interact,the dominant pattern is two sets of fractures intersecting the main fault at small angles and one set at larger angles,facilitating the formation of large-scale reservoirs.We propose a model for the fault core,which primarily consists of a calcite band and fault breccias.These breccias are composed of original host rock,calcite cement and quartz,which exhibit poor physical properties,while fractures and vugs show favorable reservoir characteristics.This model offers valuable insights into the development of fault-controlled reservoirs,particularly in the Tarim Basin.展开更多
The Longmenshan(LMS)fault zone is located at the junction of the eastern Tibetan Plateau and the Sichuan Basin and is of great significance for studying regional tectonics and earthquake hazards.Although regional velo...The Longmenshan(LMS)fault zone is located at the junction of the eastern Tibetan Plateau and the Sichuan Basin and is of great significance for studying regional tectonics and earthquake hazards.Although regional velocity models are available for the LMS fault zone,high-resolution velocity models are lacking.Therefore,a dense array of 240 short-period seismometers was deployed around the central segment of the LMS fault zone for approximately 30 days to monitor earthquakes and characterize fine structures of the fault zone.Considering the large quantity of observed seismic data,the data processing workflow consisted of deep learning-based automatic earthquake detection,phase arrival picking,and association.Compared with the earthquake catalog released by the China Earthquake Administration,many more earthquakes were detected by the dense array.Double-difference seismic tomography was adopted to determine V_(p),V_(s),and V_(p)/V_(s)models as well as earthquake locations.The checkerboard test showed that the velocity models have spatial resolutions of approximately 5 km in the horizontal directions and 2 km at depth.To the west of the Yingxiu–Beichuan Fault(YBF),the Precambrian Pengguan complex,where most of earthquakes occurred,is characterized by high velocity and low V_(p)/V_(s)values.In comparison,to the east of the YBF,the Upper Paleozoic to Jurassic sediments,where few earthquakes occurred,show low velocity and high V_(p)/V_(s)values.Our results suggest that the earthquake activity in the LMS fault zone is controlled by the strength of the rock compositions.When the high-resolution velocity models were combined with the relocated earthquakes,we were also able to delineate the fault geometry for different faults in the LMS fault zone.展开更多
The BozdağHigh is a metamorphic core complex located between the Gediz(Alaşehir)and Küçük Menderes grabens in the Western Anatolia Extensional Province.The region is structurally controlled by low-angle...The BozdağHigh is a metamorphic core complex located between the Gediz(Alaşehir)and Küçük Menderes grabens in the Western Anatolia Extensional Province.The region is structurally controlled by low-angle Gediz Detachment Faults(GDF)and high-angle normal faults,which play a fundamental role in its geomorphological evolution.Understanding how these fault systems interact to shape uplift,drainage reorganization,and landscape dynamics remains an open scientific question.This study utilizes GIS-based morphometric analyses of 53 drainage basins and mountain fronts to quantify the spatial variations in uplift and fault activity.By integrating geomorphic indices(e.g.,χ-index,ksn,Smf,Vf)with analytical hierarchy process(AHP)models,we assess relative tectonic activity and investigate the kinematic evolution of fault-bounded blocks.Our findings reveal that the BozdağHigh experienced distinct rotational phases before and after the activation of high-angle faults,transitioning from an initial detachment-dominated extensional system to a segmented fault network.Additionally,BozdağHigh exhibits contrasting tectonic activity between its northern and southern flanks.While the northern flank,facing the Gediz Graben,experiences higher uplift rates and stronger tectonic forcing,the southern flank,adjacent to the Küçük Menderes Graben,exhibits relatively subdued tectonic activity and increased erosional modification.The western section of the eastern flank shows a more rapid uplift trend toward the east,whereas the southern flank displays significant surface tilting.Geomorphic evidence suggests that sequential fault activity and strain partitioning control differential uplift,drainage divide migrations,and basin asymmetry.Asymmetric basins in the southern sector,characterized by high hypsometric integral(HI)and low normalized steepness index(ksn)values,suggest a balance between erosional processes and tectonic uplift.In contrast,regions with ongoing rapid uplift exhibit higher ksn values and active knickpoint formation.These results provide new insights into the interaction between lowand high-angle fault systems and contribute to the broader understanding of tectonic evolution in extensional provinces.These new insights include the identification of spatially variable uplift and rotation patterns caused by sequential activation of low-and high-angle faults,revealing how block tilting and strain partitioning have shaped drainage reorganization and landscape evolution in the BozdağHigh.展开更多
基金Supported by the National Natural Science Foundation of China(42472190)Chongqing Natural Science Foundation Innovation and Development Joint Fund Project(CSTB2022NSCQ-LZX0020)Chongqing Talent Innovation and Entrepreneurship Leading Talent Project(0255-19230101042)。
文摘Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods of the coal-bearing formations were determined,and the fault systems were divided.Combined with the coal seam thickness and actual gas indication in logging,the controls of fault systems in the rift basin on the spatial distribution of coal and the occurrence of coal-rock gas were identified.The results show that the Wangfu fault depression is an asymmetrical graben formed under the control of basement reactivated strike-slip T-rupture,and contains coal-bearing formations and five sub-types of fault systems under three types.The horizontal extension strength,vertical activity strength and tectono-sedimentary filling difference of basement faults control vertical stratigraphic sequences,accumulation intensity,and accumulation frequency of coal seam in rift basin.The structural transfer zone formed during the segmented reactivation and growth of the basement faults controls the injection location of steep slope exogenous clasts.The filling effect induced by igneous intrusion accelerates the sediment filling process in the rift lacustrine area.The structural transfer zone and igneous intrusion together determine the preferential accumulation location of coal seams in the plane.The faults reactivated at the basement and newly formed during the rifting phase serve as pathways connecting to the gas source,affecting the enrichment degree of coal-rock gas.The vertical sealing of the faults was evaluated by using shale smear factor(SSF),and the evaluation criterion was established.It is indicated that the SSF is below 1.1 in major coal areas,indicating favorable preservation conditions for coal-rock gas.Based on the influence factors such as fault activity,segmentation and sealing,the coal-rock gas accumulation model of rift basin was established.
基金supported by National Natural Science Foundation of China under Project 52437003 and 52421004in part by the National Key R&D Program of China under Project 2023YFB3406000in part by Heilongjiang Provincial Natural Science Foundation under Project YQ2022E029.
文摘Permanent-magnet synchronous machines(PMSMs)are widely used in robotics,rail transportation,and electric vehicles owing to their high power density,high efficiency,and high power factor.However,PMSMs often operate in harsh environments,where critical components such as windings and permanent magnets(PMs)are susceptible to failures.These faults can lead to a significant degradation in performance,posing substantial challenges to the reliable operation of PMSMs.This paper presents a comprehensive review of common fault types in PMSMs,along with their corresponding fault diagnosis and fault-tolerant control strategies.The underlying mechanisms of typical faults are systematically analyzed,followed by a detailed comparison of various diagnostic and fault-tolerant control methods to evaluate their respective advantages and limitations.Finally,the review concludes by identifying key research gaps in PMSM fault diagnosis and fault-tolerant control,while proposing potential future directions for advancing this field.
基金supported by the National Natural Science Foundation of China(No.U21B2062).
文摘The isolated fracture-vug systems controlled by small-scale strike-slip faults within ultra-deep carbonate rocks of the Tarim Basin exhibit significant exploration potential.The study employs a novel training set incorporating innovative fault labels to train a U-Net-structured CNN model,enabling effective identification of small-scale strike-slip faults through seismic data interpretation.Based on the CNN faults,we analyze the distribution patterns of small-scale strike-slip faults.The small-scale strike-slip faults can be categorized into NNW-trending and NE-trending groups with strike lengths ranging 200–5000 m.The development intensity of small-scale strike-slip faults in the Lower Yingshan Member notably exceeds that in the Upper Member.The Lower and Upper Yingshan members are two distinct mechanical layers with contrasting brittleness characteristics,separated by a low-brittleness layer.The superior brittleness of the Lower Yingshan Member enhances the development intensity of small-scale strike-slip faults compared to the upper member,while the low-brittleness layer exerts restrictive effects on vertical fault propagation.Fracture-vug systems formed by interactions of two or more small-scale strike-slip faults demonstrate larger sizes than those controlled by individual faults.All fracture-vug system sizes show positive correlations with the vertical extents of associated small-scale strike-slip faults,particularly intersection and approaching fracture-vug systems exhibit accelerated size increases proportional to the vertical extents.
基金financial support from the National Key R&D Program of China (No. 2021YFC3000600)National Natural Science Foundation of China (No. 41872206)National Nonprofit Fundamental Research Grant of China, Institute of Geology, China, Earthquake Administration (No. IGCEA2010)
文摘The three-dimensional(3D)geometry of a fault is a critical control on earthquake nucleation,dynamic rupture,stress triggering,and related seismic hazards.Therefore,a 3D model of an active fault can significantly improve our understanding of seismogenesis and our ability to evaluate seismic hazards.Utilising the SKUA GoCAD software,we constructed detailed seismic fault models for the 2021 M_(S)6.4 Yangbi earthquake in Yunnan,China,using two sets of relocated earthquake catalogs and focal mechanism solutions following a convenient 3D fault modeling workflow.Our analysis revealed a NW-striking main fault with a high-angle SW dip,accompanied by two branch faults.Interpretation of one dataset revealed a single NNW-striking branch fault SW of the main fault,whereas the other dataset indicated four steep NNE-striking segments with a left-echelon pattern.Additionally,a third ENE-striking short fault was identified NE of the main fault.In combination with the spatial distribution of pre-existing faults,our 3D fault models indicate that the Yangbi earthquake reactivated pre-existing NW-and NE-striking fault directions rather than the surface-exposed Weixi-Qiaohou-Weishan Fault zone.The occurrence of the Yangbi earthquake demonstrates that the reactivation of pre-existing faults away from active fault zones,through either cascade or conjugate rupture modes,can cause unexpected moderate-large earthquakes and severe disasters,necessitating attention in regions like southeast Xizang,which have complex fault systems.
基金supported by the National Natural Science Foundation of China(12072090).
文摘This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hypersonic vehicles.In order to increase the control amount,this online control legislation makes use of model predictive control(MPC)that is based on the concept of iterative learning control(ILC).By using offline data to decrease the linearized model’s faults,the strategy may effectively increase the robustness of the control system and guarantee that disturbances can be suppressed.An adaptive fault observer is created based on the suggested ILMPC approach in order to enhance overall fault tolerance by estimating and compensating for actuator disturbance and fault degree.During the derivation process,a linearized model of longitudinal dynamics is established.The suggested ILMPC approach is likely to be used in the design of hypersonic vehicle control systems since numerical simulations have demonstrated that it can decrease tracking error and speed up convergence when compared to the offline controller.
基金Yongxian Huang supported by Projects of Guangzhou Science and Technology Plan(2023A04J0409)。
文摘To accurately diagnosemisfire faults in automotive engines,we propose a Channel Attention Convolutional Model,specifically the Squeeze-and-Excitation Networks(SENET),for classifying engine vibration signals and precisely pinpointing misfire faults.In the experiment,we established a total of 11 distinct states,encompassing the engine’s normal state,single-cylinder misfire faults,and dual-cylinder misfire faults for different cylinders.Data collection was facilitated by a highly sensitive acceleration signal collector with a high sampling rate of 20,840Hz.The collected data were methodically divided into training and testing sets based on different experimental groups to ensure generalization and prevent overlap between the two sets.The results revealed that,with a vibration acceleration sequence of 1000 time steps(approximately 50 ms)as input,the SENET model achieved a misfire fault detection accuracy of 99.8%.For comparison,we also trained and tested several commonly used models,including Long Short-Term Memory(LSTM),Transformer,and Multi-Scale Residual Networks(MSRESNET),yielding accuracy rates of 84%,79%,and 95%,respectively.This underscores the superior accuracy of the SENET model in detecting engine misfire faults compared to other models.Furthermore,the F1 scores for each type of recognition in the SENET model surpassed 0.98,outperforming the baseline models.Our analysis indicated that the misclassified samples in the LSTM and Transformer models’predictions were primarily due to intra-class misidentifications between single-cylinder and dual-cylinder misfire scenarios.To delve deeper,we conducted a visual analysis of the features extracted by the LSTM and SENET models using T-distributed Stochastic Neighbor Embedding(T-SNE)technology.The findings revealed that,in the LSTMmodel,data points of the same type tended to cluster together with significant overlap.Conversely,in the SENET model,data points of various types were more widely and evenly dispersed,demonstrating its effectiveness in distinguishing between different fault types.
基金supported by the Natural Science Foundation of Xinjiang(No.2022D01C361)the National Natural Science Foundation of China(Nos.42462023,41888101)+1 种基金the Tianchi Talents Program fund(No.TCBR202105)the Startup Research Fund of Xinjiang University(No.620320044)。
文摘The Altyn Tagh fault zone(ATFZ),which defines the northern boundary of the Tibetan Plateau,is one of the most striking features related to the India/Eurasia collision.Concurrent with the strike-slip movement,vertical uplift,and topographic building have formed a~3000-4000 m height difference between the Tarim Basin(TB)in the north and the Tibetan Plateau in the south.However,the spatial uplift characteristics and mechanism have not been well understood,particularly in the Late Quaternary.This research presents a comprehensive geomorphic analysis to establish the Late Quaternary tectonic uplift pattern for the entire ATFZ.We statistically excluded climatic and lithological factors that provided prominence for tectonism;combined with leveling data,river incision rate,and seismicity data,we reveal the along-strike and across-fault vertical deformation variations.The spatial distribution of the integrated geomorphic index(IGI)suggests significant differences between the two sides of the ATFZ.The IGI values decrease with slip rates in the northwestern side of the ATF,whereas wave-like in the southeastern side.The significant along-strike deformation difference between the two sides of the ATFZ may cause by differential rheology.These findings are crucial for assessing regional seismic hazards and providing new independent data to understand the Late Quaternary deformation style of the northern boundary of the Tibetan Plateau.
文摘Mountain front faults form the boundary between mountains and adjacent plains.These faults can propagate toward the plains and escalate the risk of seismic hazard for near cities.The North Tehran Fault(NTF)is a mountain front fault bordering the Central Alborz with Tehran and Karaj plains.Structural and morphotectonic data from interpreted aerial photographs,satellite images,airborne geomagnetic data as well as field surveying have been used for detailed segmentation and evolution of the North Tehran Fault.This resulted in identification of the fault segments as the Niknamdeh,Darband,Darakeh-Garmdarreh,and Karaj from east to west.Active kinematics of these segments includes both thrusting and left-lateral components;but the dominant component is different among the segments.The Niknamdeh segment is connected to the Mosha Fault with a hard linkage,while its connection with the Darband segment is a widespread deformation zone.The connection zone between the Darband and Darakeh-Garmdarreh segments has the highest density of minor faults along the North Tehran Fault.The boundary of the Darakeh-Garmdarreh and Karaj segments is controlled by the F-3 transverse fault that has offset the NTF for~3 km right-laterally.The NTF has inverted from normal to dextral oblique fault in Miocene.The fault kinematics has changed from dextral to sinistral in Pliocene-Quaternary.Further regional oblique convergence resulted in minor fault reactivation such as relay ramp breaching faults,propagation of several footwall branches and hangingwall bypasses geometrical change of alluvial fans,and transfer of deformation front southwardly to the Tehran and Karaj plains.The findings of this paper are also applicable to other active oblique converging mountain fronts,inverted mountain front faults and the transition of deformation from these structures to the foreland basin.
文摘Seismic data plays a pivotal role in fault detection,offering critical insights into subsurface structures and seismic hazards.Understanding fault detection from seismic data is essential for mitigating seismic risks and guiding land-use plans.This paper presents a comprehensive review of existing methodologies for fault detection,focusing on the application of Machine Learning(ML)and Deep Learning(DL)techniques to enhance accuracy and efficiency.Various ML and DL approaches are analyzed with respect to fault segmentation,adaptive learning,and fault detection models.These techniques,benchmarked against established seismic datasets,reveal significant improvements over classical methods in terms of accuracy and computational efficiency.Additionally,this review highlights emerging trends,including hybrid model applications and the integration of real-time data processing for seismic fault detection.By providing a detailed comparative analysis of current methodologies,this review aims to guide future research and foster advancements in the effectiveness and reliability of seismic studies.Ultimately,the study seeks to bridge the gap between theoretical investigations and practical implementations in fault detection.
基金supported by the National Natural Science Foundation of China(Nos.42174023,42304037)the National Key Research and Development Program(No.2022YFB3903602)+1 种基金the Natural Science Foundation of Hunan Province(No.2024JJ3031)the Frontier Cross Research Project of Central South University(No.2023QYJC006)。
文摘0 INTRODUCTION Turkey is located at the intersection of the Eurasian,Anatolian,Arabian,and African tectonic plates.Due to the ongoing northward compression from the Arabian Plate,the Anatolian Plate is pushed westward in a tectonic escape mechanism,leading to the formation of the North Anatolian fault zone(NAFZ)and the East Anatolian fault zone(EAFZ)(e.g.,Bayrak et al.,2015;Duman and Emre,2013;Reilinger et al.,2006).
基金supported by the Open Funds for Hubei Key Laboratory of Marine Geological Resources,China University of Geosciences(No.MGR202303)the National Natural Science Foundation of China(No.41672110)。
文摘The Songliao Basin in northeast China is one of the largest petroliferous basins worldwide,and features the T_(2)fault system,which consists of numerous minor extensional normal faults.This study combines high-resolution 3D seismic datasets to detail the characteristics of the T_(2)fault system,contributing two key findings:(1)The T_(2)faults are confirmed as polygonal fault systems,characterized by closely spaced,layer-bounded faults with small throws,high dip angles,and random orientations,forming intricate polygonal networks.(2)The study reveals the influence of tectonic stresses on the fault system,showing spatial variations across different tectonic units.In depressions,T_(2)faults exhibit short lengths,small throws,high density,and multiple directions.In contrast,in inverted anticline belts,they have longer lengths,bigger throws,higher density,and concordant orientations.These variations demonstrate the impact of tectonic inversion on the development of T_(2)faults.The significance of this research lies in presenting a typical polygonal fault system developed in a deep lake succession and was superposed the influence by regional tectonic stress coeval with its development.The new insights facilitate a reevaluation of the T_(2)fault system's role in hydrocarbon migration and accumulation within the Songliao Basin.
基金supported by funding from the NSFC(42030306 and 41672216)the National Key R&D Program of China(2016YFC0600102-03).
文摘The largest Tan-Lu active fault system in northeastern Asia,spans approximately 3500 km in length and varies in width from 10 km to 200 km.In 1668,an earthquake with a magnitude of 8.5 occurred in Tancheng,causing the loss of over 50000 lives.To constrain the timing and process of the Tan-Lu fault system on eastern Asian margin,this study presents the field mapping,thin section observation,geochronology,and microanalysis of Weiyuanpu-Yehe ductile shear zone(WYSZ)of the northern Tan-Lu fault system.Kinematic indicators and microstructures suggest a sense of sinistral strike-slip.The deformation temperature of the mylonite is mediate to high based on the quartz deformation,c-axis fabrics.The differential stress of the shear zone is 20‒40 MPa using quartz paleopiezometry.The dikes within the shear zone yielded zircon U-Pb ages of 165‒163 Ma.However,due to the ambiguous geological relationship between the dikes and shear zone,additional geochronology is warranted.Since the Mesozoic era,based on the exposure of mylonite and dikes,the upper crust has been extensively eroded,exposing the ductile shear zone.Moreover,the understanding of the geometry and process of pre-existing structures has fundamental implications for predicating the potential earthquakes for the Tan-Lu fault system.
基金supported by the National Natural Science Foundation of China(No.U21B2062)funding from the Chinese Scholarship Council(CSC)and the American Association of Petroleum Geologists Foundation Grantsin-Aid Program.
文摘Natural fractures controlled by faults in ultradeep carbonate strata play substantial roles as both fluid migration channels and storage spaces.However,characterizing the heterogeneous distribution of underground fractures within the complex three-dimensional geometry of strike-slip fault zones remains challenging.This study investigates the characteristics of natural fractures controlled by strike-slip faults in the fractured Middle and Lower Ordovician reservoirs of the central and northern Tarim Basin,China.Seismics,cores,and image logs were integrated to quantitatively analyze the intensity and dip angle of natural fractures and findings were verified using published sandbox simulations.The carbonate reservoir contains three main types of natural fractures:tectonic fractures,abnormal high-pressure-related fractures,and stylolites.Strike-slip faults control the distribution and characteristics of tectonic fractures across various scales.Generally,both fracture intensity and porosity exhibit a decreasing trend as the distance from the main fault surface increases.Compared with those in non-stepover zones along a strike-slip fault,natural fractures and faults in stepover zones are more developed along the fault strike,with significantly greater development intensity in central stepover regions than that at its two ends.Furthermore,strike-slip faults influence the dip angles of both natural fractures and secondary faults.The proportion of medium-to-low-dip angle fractures and faults in the stepover zone is greater than that in the non-stepover zone.Additionally,the proportion of medium-to low-dip angle fractures and faults in the middle of the stepover is greater than that at both ends.Therefore,strike-slip fault structures control the dip angle of natural fracture and the heterogeneity of secondary fault and fracture intensity.The linking damage zone in the stepover contains a larger volume of fractured rocks,making it a promising petroleum exploration target.The development of stepovers and the orientation of present-day in-situ stress substantially influence the productivity of fractured reservoirs controlled by strike-slip faults.The analysis in this study reveals that reservoir productivity increases as the angle between the strike-slip fault segment and the maximum horizontal principal stress decreases.This study provides valuable insights for quantitatively evaluating fracture heterogeneity in fractured reservoirs and establishing optimized selection criteria for favorable targets in fault-related fractured reservoirs.
基金supported by the Natural Science Foundation of China-Youth Foundation(42402163)Natural Science Foundation of Sichuan Province of China(2024NSFSC0814)Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(2020CX010101).
文摘The strike-slip fault system in the central Tarim Craton controls a complex petroleum system with estimated reserves exceeding 1×10^(9)t,the fault-related fractures are important for hydrocarbon accumulation.In this paper,the basic parameters such as density and width of fractures are counted and classified,and the effects of fractures on reservoirs are analyzed.The results show that:(1)Structural fractures and stylolite were widely developed in Halahatang area and experienced at least three stages of activity based on the infilling materials and crosscutting relationship.(2)Fracture density,width,aperture,and dip angle vary in different wells,but the relationship between the above parameters and the distance to the fault core indicates the fracture differences in the fault damage zone and further provides a method to divide the inner units in the fault damage zone.In addition,oil and gas wells with high production mainly concentrate in the inner unit.(3)The infilling materials and degree of fractures vary.Fractures formed in the early stage are more filled and less open,while the fractures formed in the late stage are relatively less filled and more open.(4)Fractures improve porosity to a certain extent but greatly increase permeability,especially in the inner zone of fault damage zone with large quantity,multiple inclinations,less filling and large width.These features contribute to the formation of a higher-quality reservoir,further improving oil and gas production.This paper provides a quantitative characterization method for the study of strike-slip fault-related fracture-caved reservoirs,and points out that fault damage zone,especially the inner zone of the fault damage zone,is the potential goal for oil and gas exploration.
基金supported by the National Natural Science Foundation of China(62325304,U22B2046,62073079,62376029)the Jiangsu Provincial Scientific Research Center of Applied Mathematics(BK20233002)the China Postdoctoral Science Foundation(2023M730255,2024T171123)
文摘Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the continuous fault-tolerant control protocol via observer design is developed. In addition, it is strictly proved that the multi-agent system driven by the designed controllers can still achieve bipartite consensus tracking after faults occur.
基金financially supported by the Natural Science Foundation of Chongqing,China(No.cstc2020jcyj-msxm X0487)the Open Fund of Key Laboratory of Sedimentary Basins and Oil and Gas Resources,the Ministry of Natural Resources(No.cdcgs2022006)+2 种基金the National Natural Science Foundation of China(No.42072001)the China Geological Survey(No.DD20190018)the Science and Technology Innovation Fund for Postgraduates of Chongqing University of Science and Technology(No.YKJCX2220101)。
文摘Riedel shear system,which consists of some different oriented faults and derivative structures,is an important pattern of tectonic activity and stress regulation,which has been widely applied to the interpretation of intracontinental deformation.The Laolongwan Basin,located in the western Haiyuan fault zone at the northeastern Tibetan Plateau,is a key area to study the Cenozoic intracontinental deformation in the northeastern plateau,which formed a complex active fault system during the Cenozoic.However,the activity of these faults and their kinematic mechanism remain unclear.In this contribution,based on detailed structural interpretation of remote sensing image,field observations and OSL dating analysis,we propose a Riedel Shear model of active fault system in the Laolongwan Basin.Our observations show that this active fault system consist of four major faults,including the left strike-slip Hasi Shan fault and Zihong Shan fault with thrusting characteristics,the Southern Zihong Shan thrust fault and the Mijia Shan normal fault.The fault offset and OSL dating analyses suggest that the left-lateral slip rate of the Hasi Shan fault is~2.60-3.01 mm/a since ca.15 ka,whereas the Zihong Shan fault is~1.10-1.13 mm/a since ca.14 ka.Faultslip vectors analyses indicate that the active fault system related to the Riedel Shear in the Laolongwan Basin was controlled by the regional ENE-WSW compressive stress.This compression also caused the significant left-lateral strike-slip movement along the Haiyuan fault zone at the same time,which might result from the northeastward continuous expanding of the Tibetan Plateau during the Late Cenozoic.
基金supported by the National Natural Science Foundation of China(Grant No.U21B2062).
文摘Recent exploration has highlighted the critical role of strike-slip faults in shaping ultra-deep carbonate reservoirs in the Tarim Basin.This study integrates satellite imagery,UAV photogrammetry,outcrop surveys and microscopic analysis to investigate the architecture of these faults and their impact on reservoir petrophysical properties.The strike-slip faults exhibit cores consisting of calcite bands,fault breccias and fractures,while the damage zones are predominantly fractured.Thicker fault cores and fault zones are associated with more extensive reservoir development.Individual strike-slip fault zones are primarily characterized by two sets of fractures intersecting the fault at small angles.When two fault systems interact,the dominant pattern is two sets of fractures intersecting the main fault at small angles and one set at larger angles,facilitating the formation of large-scale reservoirs.We propose a model for the fault core,which primarily consists of a calcite band and fault breccias.These breccias are composed of original host rock,calcite cement and quartz,which exhibit poor physical properties,while fractures and vugs show favorable reservoir characteristics.This model offers valuable insights into the development of fault-controlled reservoirs,particularly in the Tarim Basin.
基金supported by the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology under Grant 2024yjrc64the National Key R&D Program of China under Grant 2018YFC1504102。
文摘The Longmenshan(LMS)fault zone is located at the junction of the eastern Tibetan Plateau and the Sichuan Basin and is of great significance for studying regional tectonics and earthquake hazards.Although regional velocity models are available for the LMS fault zone,high-resolution velocity models are lacking.Therefore,a dense array of 240 short-period seismometers was deployed around the central segment of the LMS fault zone for approximately 30 days to monitor earthquakes and characterize fine structures of the fault zone.Considering the large quantity of observed seismic data,the data processing workflow consisted of deep learning-based automatic earthquake detection,phase arrival picking,and association.Compared with the earthquake catalog released by the China Earthquake Administration,many more earthquakes were detected by the dense array.Double-difference seismic tomography was adopted to determine V_(p),V_(s),and V_(p)/V_(s)models as well as earthquake locations.The checkerboard test showed that the velocity models have spatial resolutions of approximately 5 km in the horizontal directions and 2 km at depth.To the west of the Yingxiu–Beichuan Fault(YBF),the Precambrian Pengguan complex,where most of earthquakes occurred,is characterized by high velocity and low V_(p)/V_(s)values.In comparison,to the east of the YBF,the Upper Paleozoic to Jurassic sediments,where few earthquakes occurred,show low velocity and high V_(p)/V_(s)values.Our results suggest that the earthquake activity in the LMS fault zone is controlled by the strength of the rock compositions.When the high-resolution velocity models were combined with the relocated earthquakes,we were also able to delineate the fault geometry for different faults in the LMS fault zone.
文摘The BozdağHigh is a metamorphic core complex located between the Gediz(Alaşehir)and Küçük Menderes grabens in the Western Anatolia Extensional Province.The region is structurally controlled by low-angle Gediz Detachment Faults(GDF)and high-angle normal faults,which play a fundamental role in its geomorphological evolution.Understanding how these fault systems interact to shape uplift,drainage reorganization,and landscape dynamics remains an open scientific question.This study utilizes GIS-based morphometric analyses of 53 drainage basins and mountain fronts to quantify the spatial variations in uplift and fault activity.By integrating geomorphic indices(e.g.,χ-index,ksn,Smf,Vf)with analytical hierarchy process(AHP)models,we assess relative tectonic activity and investigate the kinematic evolution of fault-bounded blocks.Our findings reveal that the BozdağHigh experienced distinct rotational phases before and after the activation of high-angle faults,transitioning from an initial detachment-dominated extensional system to a segmented fault network.Additionally,BozdağHigh exhibits contrasting tectonic activity between its northern and southern flanks.While the northern flank,facing the Gediz Graben,experiences higher uplift rates and stronger tectonic forcing,the southern flank,adjacent to the Küçük Menderes Graben,exhibits relatively subdued tectonic activity and increased erosional modification.The western section of the eastern flank shows a more rapid uplift trend toward the east,whereas the southern flank displays significant surface tilting.Geomorphic evidence suggests that sequential fault activity and strain partitioning control differential uplift,drainage divide migrations,and basin asymmetry.Asymmetric basins in the southern sector,characterized by high hypsometric integral(HI)and low normalized steepness index(ksn)values,suggest a balance between erosional processes and tectonic uplift.In contrast,regions with ongoing rapid uplift exhibit higher ksn values and active knickpoint formation.These results provide new insights into the interaction between lowand high-angle fault systems and contribute to the broader understanding of tectonic evolution in extensional provinces.These new insights include the identification of spatially variable uplift and rotation patterns caused by sequential activation of low-and high-angle faults,revealing how block tilting and strain partitioning have shaped drainage reorganization and landscape evolution in the BozdağHigh.
