Fault System Research Articles

Integration of deep-learning fault segmentation, horizontal transverse isotropy analysis, and ambient microseismic methods to enhance fracture prediction in the Crisol Anticline, Colombia

The analysis of fault and fracture systems in the subsurface is crucial for identifying potential reservoirs and optimizing production. However, conventional fault interpretation methods have limitations due to the complexity and amount of data involved. In this study, a multimethod approach was used to analyze fault and fracture systems in the Crisol area of the Valley Middle Magdalena basin. We used deep-learning fault segmentation, horizontal transverse isotropy (HTI), and ambient microseismic methods to identify and characterize fault and fracture systems in the study area. The deep-learning fault segmentation method helped to identify complex fault systems, whereas the HTI method identified areas and orientations of intense fracturing that occurred at any prior period of stress in geologic time. Meanwhile, the ambient microseismic method measured active rock movements and fracturing in the subsurface that occurred during the microseismic trace recording. The application of multiple methods for analyzing fault and fracture systems in the subsurface is demonstrated to offer a more comprehensive understanding of the geology and enhance the accuracy of well placement and production forecasts.

Fault structure and hydrocarbon prospects of the Palawan Basin on the southeastern margin of the South China Sea based on gravity, magnetic, and seismic data

To study the structural features and hydrocarbon prospects of the Palawan Basin in the South China Sea (SCS), the authors collect and collate the existing gravity and magnetic data and obtain edge recognition information from the potential fields. Combined with the seismic profile data, this paper analyzes the features of the gravity and magnetic anomalies and the edge recognition information of the potential fields, determines the fault system, and delineates favorable areas for oil and gas exploration in the Palawan Basin. The results indicate that four main groups of faults with northeast, northwest, near east–west, and near south–north trends developed in the Palawan Basin and adjacent areas in the SCS. The northeast-trending fault is the regional fault, whereas the northwest-trending fault is the main fault. The northwest-trending fault often terminated at the northeast-trending fault, indicating that the northwest-trending fault is formed subsequently. This investigation has characterized two different types of exploration favorable areas (type I and type II) based on the characteristics observed. The most notable characteristic of these exploration favorable areas is that they are located in the high-value zones of the local anomaly of the Bouguer gravity anomaly and their development is obviously controlled by the faults. The amplitude of the gravity anomalies is higher and the gradient of the gravity anomalies is steeper, and there are oil and gas wells and fields distributed in the type I favorable areas for exploration. Compared with the type I favorable areas, the amplitude of gravity anomalies is relatively small, and the gradient of the gravity anomalies is relatively gentle, corresponding to the type II favorable areas.

ОЦІНЮВАННЯ ВПЛИВУ ЗАСОБІВ ПІДКЛЮЧЕННЯ РЕЗЕРВУ НА ПОКАЗНИКИ НАДІЙНОСТІ СИСТЕМИ ПЕРЕДАВАННЯ ДАНИХ

Structural redundancy is included in modern data transmission systems to ensure the specified reliability indicators. Structural redundancy gives the system fault tolerance and significantly increases its reliability. To manage the redundant resource, it is necessary to have additional tools that will connect the redundant equipment to the main configuration of the data transmission system. The redundant equipment is a separate technical means and, from the point of view of reliability, it is connected in series with other modules of the data transmission system. Thus, the inclusion of redundant connection facilities in the data transmission system reduces its reliability. In addition, even with perfect reliability, redundant connections may fail or malfunction and, under certain conditions, cause the transmission system to fail. To determine the impact of reserve connection facilities on the reliability of the transmission system, the article applies an original technology for building models of discrete-continuous stochastic systems. ASNA software was used as a software tool for modeling the reliable behavior of the data transmission system. This software provides automated construction of the model in the form of a graph of states and transitions based on a structural automaton model. Based on the graph of states and transitions, an analytical model is automatically generated in the form of a system of linear differential Kolmogorov-Chapman equations. Using the developed model, the article quantitatively analyzes the impact of redundant connection means (switches) on the reliability indicators of the data transmission system. In the study, the proposed models, unlike the existing ones, take into account both reliability indicators (probability of failure) and functionality indicators (probability of switching, speed) of the reserve connection means. On the basis of the developed model, the limit values of reliability and functionality of the redundant connection means (switches) were determined, at which they will minimize the reliability of the fault-tolerant data transmission system. Based on the analysis of the obtained results, practical recommendations for the selection of reliability indicators of the backup connection means, their speed and probability of switching are formed.

Contribution of VLF electromagnetic survey to the investigation of Hessdalen lights (Norway)

Hessdalen valley in Norway is known for luminous phenomena suddenly and evenly appearing temporarily. Since several decades, these phenomena are observed by many witnesses, and they are sometimes traced by geophysical devices. The first appearance in modern times was reported in 1981 but systematic observations started during winter of 1984 when the Hessdalen project was launched. Later, Østfold University College led the project and yearly organized one to two field campaigns, with the objective to systematically record and investigate the phenomenon. Till that epoch, detailed tectonics, fault systems and superficial conductive structures remained unknown. Therefore, during the last years, VLF surveys have been performed in Hessdalen valley as part of six geophysical field campaigns which sometimes also included Total Magnetic Field and Self Potential spatial ground measurements. VLF measurements have been carried out on a 20 m average spacing along many traces totaling to100 km length. The entire covered area was about 100 km2.In this paper, we focus on the results of the VLF measurements. Several conductive zones have been found. They are mainly related to mineral deposits (mainly sulfides). The trace at the ground surface of these conductive zones could suggest that they draw an ellipse of 6 by12 km, related to the shape of the gabbro intrusion present in the area and oriented in the SW-NE direction. The results combined with other geophysical data contribute to better understand how the near surface structures (depth less than a few hundred meters) could supply the generation of the so-called Hessdalen lights (‘HL’) and explain why these lights appear inside this valley. The particular geological structure detected in Hessdalen valley may encourage similar campaigns in other areas where similar phenomena are observed.

HeMTAN: Hybrid task-adapted experts-based multi-task attention network for unseen compound fault decoupling diagnosis of rotating machinery

In a rotating machinery system, a single fault of one component often causes damage to other related components, thus inducing compound faults. Without compound fault data to train intelligent models, the realization of decoupling diagnosis and accurate identification of unseen compound faults is not only of great practical significance for the safety management of equipment operation and maintenance, but also remains a challenging topic. Considering some shortcomings in the current intelligent diagnosis of compound faults, as well as the relatedness and difference between different fault features in compound fault signals, a hybrid task-adapted experts-based multi-task attention network (HeMTAN) model is investigated in this paper, which can be used for identify single faults and unseen compound faults in mechanical transmission systems. Firstly, variational mode decomposition is combined with Hilbert-Huang transform to obtain time–frequency graphs of time series signal as model input, so as to better characterize different fault features. Secondly, a hybrid task-adapted expert module is designed to extract the common and some private feature information of different learning tasks from different multi-perspective, and then the important information related to the specific learning task is further mined by the constructed private feature attention-based densely connected module. Finally, the diagnosis results can be obtained by fusing the outputs of the classifier of the two learning tasks. The performance of the investigated HeMTAN model is analyzed by the gearbox compound fault dataset and rolling bearing compound fault dataset, and the results demonstrate that the investigated HEMTAN method has significantly improved diagnosis accuracy and generalization performance.

Traveling-wave-based Fault Location using Time Delays between Modal Components in Electrical Distribution Systems

Background: The distribution feeders usually include many laterals, too many sensors need to be installed to locate the fault positions in electrical distribution systems by using the traditional double-ended traveling-wave-based fault-location methods Objective: Fault location based on the time delays between the moments of the first wavefronts of zero-mode voltages and that of aerial-mode voltages arriving at one end of the distribution feeder. Methods: Large decomposition level in wavelet transformation is adopted in this paper to obtain the zero-mode velocity. Results: Both theoretical research and simulation experiments have proved that the proposed fault location method can greatly improve the accuracy of the fault location in the electrical distribution systems without many sensors. Conclusion: The proposed fault location method can provide one feasible way to locate the faults in the electrical distribution systems.

A hybrid clustering approach integrating first-principles knowledge with data for fault detection in HVAC systems

The building sector, primarily through heating, ventilation, and air conditioning (HVAC) systems, accounts for over 30% of global final energy consumption and 26% of energy-related emissions, highlighting the urgency for efficient energy management and effective fault detection. Optimizing HVAC system performance is crucial for energy conservation and sustainability. This study introduces a hybrid modeling methodology to enhance HVAC systems’ fault detection and isolation (FDI). Using feature extraction through principal component analysis (PCA) and autoencoder (AE), the proposed approach integrates first-principles knowledge with data to improve the performance of different clustering algorithms (K-means, density-based spatial clustering of applications with noise (DBSCAN), and ordering points to identify the clustering structure (OPTICS)) to distinguish datasets of different operating conditions (normal and faulty conditions). The proposed approach is applied to detect common faults in HVAC systems, demonstrating superior performance compared to purely data-driven methods.

On the effects of pitch system faults on a wind turbine

In this study, the hydraulic pitch system of the DTU 10 MW reference wind turbine has been modelled, including different component-level faults, and the control algorithms have been modified to influence the effect of these faults on loads, production and robustness. The simulation results show that the performance of the pitch system model is similar to others in the literature, while at the same time simulating the hydraulic supply pressure variations. The results also show the importance of these variations for overall turbine performance. The number of safety events due to low supply pressure increases with the severity of internal hydraulic leaks. This can be mitigated with a control strategy which limits negative pitch rates based on accumulator pressure. The results show that this can preserve up to 100% of power production in the face of very severe pitch system faults, with as little as 0% impact on loads.

A case of paleoseismic evidence of normal fault capable of triggering an M>8 earthquake − study on Sertengshan range-front fault, north margin of Hetao Basin, China

The Sertengshan Range-front Fault (SRF) and Langshan Range-front Fault (LRF) constitute a normal fault system on the northern boundary of the Linhe Depression in its northwest, and an investigation of the LRF–SRF is significant for understanding the seismic activities of normal faults. We set four trenches at three study sites to reveal paleo-earthquakes in the western segment of the SRF (W-SRF) in this system, and established 5 surface rupture events along W-SRF since the Late Pleistocene. By integrating paleoseismic data from 27 trenches on multiple fault segments, we reconstructed the paleoseismic sequence for the LRF–SRF region since 15 ka, and identified 10 paleoseismic events with corresponding rupture segments and magnitudes. The slip rates at the three study sites decreased gradually from the west to east on the W-SRF, by comparing with previous studies, further evidencing that the tectonic activities of the two faults have gradually synchronized. Besides, based on the timing of the latest paleoseismic event (1.88−2.03 ka BP), earthquakes of > M 8 surface ruptures of >200 km can occur in the northwestern Ordos Block and its seismic behavior revealed the seismogenic possibility of normal faults triggering an M > 8 earthquake.

Effect of crustal stress state on magmatic stalling and ascent: case study from Puyehue-Cordón Caulle, Chile

The Southern Volcanic Zone (SVZ) in Chile is an active continental arc with a complex history of volcanism, where a range of magmatic compositions have been erupted in a variety of styles. In the Central SVZ, both monogenetic and polygenetic volcanoes exist, in close proximity to the Liquiñe-Ofqui Fault System (LOFS), but with variable local stress states. Previous studies have inferred varying crustal storage timescales, controlled by the orientation of volcanic centres relative to the N-S striking LOFS and σHMax in this region. To assess the relationship between volcanism and crustal stress states affected by large-scale tectonic structures and edifice controls, we present whole rock geochemical data, to ensure consistency in source dynamics and crustal processing, mineral-specific compositional data, thermobarometry, and Fe–Mg diffusion modelling in olivine crystals from mafic lavas, to assess ascent timescales, from the stratovolcanic edifice of Puyehue-Cordón Caulle and proximal small eruptive centres. Textural observations highlight differences in crystal maturation timescales between centres in inferred compression, transpression, and extension, yet source melting dynamics remain constant. Only samples from the stratovolcanic edifice (in regional compression) preserve extensive zonation in olivine macrocrysts; these textures are generally absent from proximal small eruptive centres in transtension or extension. The zonation in olivines from stratovolcanic lavas yields timescales on the order of a few days to a few weeks, suggesting that even in environments which inhibit ascent, timescales between unrest and eruption of mafic magmas may be short. Significantly, high-resolution compositional profiles from olivine grains in the studied samples record evidence for post-eruptive growth and diffusion, highlighting the importance of careful interpretation of diffusion timescales from zoned minerals in more slowly cooled lavas when compared with tephra samples.

Origin, distribution, and CO2 EOR and CO2 storage resource assessment of selected residual oil zone fairways in the Illinois Basin

Residual Oil Zones (ROZs) are volumes of rock with low, largely immobile, oil saturations that provide opportunities for low carbon intensity oil production via carbon dioxide enhanced oil recovery (CO2-EOR) and associated CO2 storage. Oil shows of varying degree have been observed throughout the Illinois Basin (ILB). This work is the first to assess these shows as ROZs.In the ILB, the distribution of ROZ fairways and prospects is controlled by the geologic setting and oil migration history of the basin. ILB ROZ fairways that are stratigraphically proximal to the source rock are generally widespread whereas fairways developed in formations with a greater thickness of intervening strata are more discrete, an indication of influence from fault systems and fracturing associated with major structures. Within these fairways, 41 ROZ prospects were defined across three formations (Tar Springs Sandstone, Cypress Sandstone, Carper Sandstone) containing a best estimate (P50) of five billion barrels (bbls) of original oil in place (OOIP). For context, this volume is 35% of the estimated 14.1 billion bbls of OOIP in the conventional reservoirs in the ILB. In comparison to the Permian Basin, the ILB ROZ OOIP volume is 20% of the estimated 25 billion bbl of ROZ OOIP within a nine-county area of the San Andres Formation.The CO2-EOR resource of the ILB ROZ prospects exceeds 518 million bbls of oil using CO2 injection via pattern flooding. Associated CO2 storage is estimated to be 411 million tonnes of CO2. This study builds on past efforts to establish the CO2-EOR and associated CO2 storage resource potential of the ILB and presents a methodology that can be used to assess ROZ resources in other parts of the world.

Research on Fault Identification of Hybrid Multi-Feed High-Voltage Direct Current System Based on Line Commutated Converter and Voltage Source Converter

With the rapid development of voltage source converter (VSC) and line commutated converter (LCC) technology and the relative concentration of power and load, the inverter station of the flexible DC system is fed into the same AC bus with the conventional DC rectifier station, and the high-voltage direct current (HVDC) parallel hybrid feed system is formed in structure. As the electrical distance between the converter stations is very close, when a fault occurs in the near area, the current on the AC wiring on the VSC side will fluctuate greatly, resulting in the misoperation of the AC wiring protection. For this reason, this paper proposes a fault identification method based on VSC/LCC hybrid multi-fed HVDC system, which discriminates the fault and outputs the protection signal according to the protection criterion, and logically judges the combination of the output protection signal to identify the fault type. The simulation results show that the method can identify all kinds of faults of hybrid multi-feed DC system and solve the problem of protection misoperation of the hybrid multi-feed DC system.

Study on the Vibration Characteristics of the Helical Gear-Rotor-Bearing Coupling System of a Wind Turbine with Composite Faults

As the core component of the wind turbine generation gearbox, the gear-rotor-bearing transmission system typically operates in harsh environments, inevitably leading to the occurrence of composite faults in the system, which exacerbates system vibration. Therefore, it is necessary to study the vibration characteristics of wind turbine helical gear-rotor-bearing transmission systems with composite faults. This paper uses an improved energy method to calculate the theoretical time-varying mesh stiffness of a helical gear with a root crack failure. On the premise of considering the time-varying meshing stiffness of the faulty helical gear, the gear eccentric fault, and the nonlinear support force of the faulty bearing, a multi-degree-of-freedom helical gear-rotor-bearing transmission system with compound faults was established by using the lumped parameter method. The dynamic model of the system was solved based on the Runge–Kutta method, and the vibration response of the system under healthy conditions, single faults with gear eccentricity, single faults with tooth root cracks, and coupled bearing composite faults were simulated and analyzed. The results show that the simulation results based on KISSsoft software 2018 version verify the effectiveness of the improved energy method; the existence of single faults and composite faults will cause the fault characteristics in the time domain and frequency domain responses. In this paper, the influence of a single fault and a complex fault on the time domain and frequency domain of the system is mainly discovered through the fault study of the helical rotor-bearing system, and the influence of the fault degree on the vibration of the gear motion system is discussed. The greater the degree of the fault, the more vibration of the system occurs; accordingly, when the system is under the coupling of tooth root crack and bearing fault, there is a significant difference compared with the healthy system and the single fault system. The system vibration has obvious time domain and frequency domain signal characteristics, including periodic pulse impacts caused by gear faults and time domain impact caused by bearing. The fault characteristic frequencies can also be found in the frequency domain. In this paper, the fault study of a helical gear of wind turbine generation provides a reference for the theoretical analysis of the vibration characteristics of the helical gear-rotor-bearing system under various fault conditions, lays a solid foundation for the simulation and subsequent diagnosis of the composite fault signal of the system, and provides help for the fault diagnosis of wind turbine gearboxes in the future.

The Nieve volcanic cluster: A Pliocene - Pleistocene lava dome cluster in the Michoacán-Guanajuato volcanic field (México)

The Nieve monogenetic volcanic cluster is located in the central–eastern region of the Michoacán–Guanajuato volcanic field, along the Huiramba fault zone, a relay ramp in the Morelia–Acambay fault system produced by oblique north-northwest transtension. This volcanic cluster includes at least 17 middle Pliocene to late Pleistocene lava domes, two small shield volcanoes, and two scoria cones. Between 4 and 3.8 Ma, two effusive eruptions built two small shield volcanoes overlying one another, with a magma volume of 3.93 km3. Between 2.9 Ma and 21.4 ka, 17 lava domes and two scoria cones were emplaced on the flanks of these volcanoes. The entire cluster resulted in a total erupted volume of 17 km3, covering an area of 326 km2 and reaching a thickness of emplaced volcanic material of 1200 m, resulting in a magma eruption rate equivalent to 0.004 km3/ka. All the rocks associated with this cluster are within a relatively restricted range in composition, between 53.9 and 64.2 wt% SiO₂, from andesite enriched in silica to basaltic andesite. The presence of intrusive-rock xenoliths and xenocrysts with dissolution textures reveals that assimilation processes modified the magmas. Based on the regional geological record, we suggest that the establishment of the Nieve volcanic cluster has been controlled by tectonic structures and the basement of the region, which has allowed the chemical evolution of these magma batches that probably had sources in at least two deep reservoirs as reflected by the Nb/Th versus Ta/U ratio.

Long live the fault! Double inversion of a Mesozoic rift‐related fault system in the central Apennines

AbstractThe San Potito area in central Apennines (Italy), enclosed within the Latium‐Abruzzi carbonate platform, exposes anomalously pelagic carbonates filling an intraplatform basin formed during Jurassic rifting. Oriented obliquely to the regional NW‐SE trend of Cenozoic thrusts and extensional faults, the basin's eastern boundary fault system, striking N‐S, played a pivotal role in structuring orogenic and post‐orogenic features. Large tracts of the fault experienced double reactivation: positive inversion during Miocene shortening, and negative during post‐orogenic extension. Double reactivation is evidenced by older‐on‐younger extensional contacts, and by the change in orientation of thrusts and recent extensional faults from NW‐SE to NNW‐SSE, the latter being consistent with the trend of Jurassic rift‐related structures of the area. This structural interplay highlights the importance of Jurassic faults and their ability in forcing the structural trends, by surviving across multiple deformation stages, even controlling active extensional seismicity.

Reliable high impedance fault detection method based on the roughness of the neutral current in active distribution systems

Detecting High Impedance Faults (HIFs) in Distribution Systems (DSs) still requires effective solutions. HIFs can cause damage, such as shock hazards and bushfires. However, conventional protection cannot identify HIFs due to their low fault current, and most existing solutions neglect the multiple operating scenarios of the DSs. Thus, this paper proposes a new self-adaptive approach for HIF detection, considering the conductor fall period in a system with distributed generation, a condition usually overlooked in existing studies. The algorithm is based only on the fundamental component and third harmonic extracted from the neutral current using the Stockwell Transform. The approach was thoroughly evaluated, considering several scenarios, such as changes in the system loading, background noise, events that can cause false detection, and variations in the distributed generator power output. The tests considered HIFs signals from real field measurements and generated by a simulation model. The results showed that the algorithm is promising, with high detection rates for all the evaluated scenarios, which included over 400,000 HIF and 6,000 non-HIF cases. Additionally, a comparison proved the superiority of the proposed approach over existing methodologies.

The Geodetic Signature of Bookshelf Faulting in Nicaragua

AbstractTrench‐parallel translation of the Central American Forearc (CAFA) is the result of strain partitioning along the Cocos and Caribbean (CA) convergent margin. Unlike the tectonics of northwestern Costa Rica and El Salvador, CAFA‐CA relative motion in Nicaragua is not accommodated on margin‐parallel fault systems. Rather, the northwest‐trending dextral shear is accommodated on margin‐normal sinistral strike‐slip faults that approximate the motion of a margin‐parallel fault (i.e., bookshelf faulting). We compare a new Global Positioning System interseismic horizontal velocity field to analytical and numerical models to show that the bookshelf faulting model can produce the observed velocity field and provide insight into the kinematics and configuration of the margin‐normal fault system. We find that a fault system with 20 km‐long parallel to sub‐parallel margin‐normal sinistral faults, spaced ∼5 km apart, locked from the surface to 5 km depth, and with interseismic slip deficits of 4 mm yr−1, can replicate the observed velocity field. These findings have implications for the region's seismic hazard where shallow moderate‐magnitude earthquakes will have reoccurrence intervals of ∼50 years. These findings are also important for volcanic hazard estimation and unrest forecasting because the margin‐normal faults are in the volcanic arc and magma‐tectonic interactions have been documented along the CAFA.

Constraints on Growth and Stabilization of the Western Superior Craton From Inversion of Magnetotelluric Data

AbstractA data set consisting of 376 broadband and long‐period MT measurements was used to generate the first ever 3D resistivity model of the Archean western Superior Craton. The modeled resistivity structure is compared to coincident seismic reflection data. The observed geophysical signatures are interpreted within the context of the late stages of crustal growth and cratonization of the region via the progressive accretion of terranes against the initial cratonic core. The northern‐most terranes comprising the cratonic core exhibit a nearly homogenous highly resistive crust. The lower crust of the southern terranes contains largely continuous low resistivity bands which run subparallel to major terrane boundaries and corresponding fault systems. In some cases, low resistivity features are coincident with dense packages of sub‐horizontal to listric reflections within the mid‐ to lower crust. These resistivity structures are inferred to represent preserved geoelectric signatures of late to post‐orogenic magmatic pulses likely related to delamination of locally overthickened crust. Increased mantle heat flow resulted in partial melting of the lower crust and upper mantle and upward migration of CO2‐rich melts and fluids through crustal weak zones corresponding to shear and/or suture zones formed during terrane amalgamation. Thermal softening of the mid‐ to lower crust led to orogenic collapse and reactivation of the crustal shear zones, resulting in formation and interconnection of graphitic films which were preserved within the stable craton. These results have implications for the tectono‐magmatic history of the western Superior Craton, as well toward the understanding of the geodynamic regime of the Archean Earth.

Determining the directions of dangerous ecogeochemical impact of surface reservoirs of highly mineralized mine and open pit waters using a complex of geological and geophysical data

The issues of effective use of geological and geophysical methods for spatial assessment of dangerous ecogeochemical impact of storage ponds of highly mineralized mine and open pit waters are considered. An example of such an object is the Svystunovo gully (volume – 12 million m3), into which water is pumped out from all working open pits and mines of Southern and partially Central Kryvbas. To solve ecogeochemical problems associated with dangerous influence of such storage ponds, a well-known method for restoring Precambrian fault systems using a complex of geological, geophysical and geomorphological data was taken. At all research scales, based on the results of calculations of the significance of “weights” of fault signs, a clear trend was revealed for predominance of diagonal fault systems with strike azimuths: 35° - 305° and 45° - 315°. The spatial combination of tectonic information with results of detailed electrical exploration work made it possible to identify local directions of propagation of dangerous ecogeochemical influence of the studied storage pond of highly mineralized waters by anomalies of decrease / increase in geoelectric resistance in the emerging geochemical block of local system of integrated environmental monitoring of Southern Kryvbas.

Structural Characterization of the Taltal Segment in Northern Chile Between 22°S and 26°S Using Local Earthquake Tomography

AbstractRecordings of earthquakes by a temporary deployment of 84 short period seismometers in northern Chile were used to derive regional 3D seismic velocity models for the Taltal segment. We used the Regressive ESTimator (REST) package for event detection and automatic onset estimation of P‐ and S‐wave arrival times to create an earthquake catalog with 23,985 hypocenters. We followed standard acceptability criteria (i.e., azimuthal gap and residual cutoff) to create a high‐quality data set and inverted for 3D Vp, Vs and Vp/Vs models using local earthquake tomography. Plots of hypocenters from the catalog, comprising 16,349 earthquakes, reveal active structures in the upper crust, dip changes along the slab and fracturing within the oceanic crust. Moreover, the wavespeed models illuminate anomalies in both the Nazca and South American plates that correlate with the observed seismicity distribution, including variations from low (1.75) to high (>1.80) Vp/Vs near the Atacama fault system on the coastline and the Domeyko Fault System in the forearc. The seismic velocity models also provide evidence for fluid circulation caused by the subducting Taltal ridge on the coast and partial melting feeding a volcanic complex close to the Andes. Finally, the observed low Vp/Vs ratios (∼1.75) are associated with copper mining operations in the area, suggesting that this kind of imaging can be used to characterize the distribution of potential ore deposits in the area.