Geophysical Domains Research Articles

Efficient and consistent adaptive mesh generation for geophysical models: A case study over the Gulf of Thailand

Geophysical domains typically exhibit intricate, irregular boundaries characterized by fractal-like geometries, while underlying physical processes operate across a broad spectrum of spatial scales. The challenge lies in generating spatial discretization of these domains that conform to their geographical constraints, utilizing anisotropic, fully adaptive meshes. This problem is compounded by the vast range of scales and a notably heterogeneous parameter space. Current methodologies often rely on ad hoc, model-specific, or application-dependent approaches, which lack comprehensive descriptions. Consequently, the development of new spatial domains is labor-intensive, prone to errors, challenging to replicate, and difficult to maintain consistency due to substantial human involvement. This predicament poses obstacles to the reproducibility of simulations and the establishment of provenance in data handling and model initialization, and it hinders rigorous model intercomparisons. Furthermore, the likelihood of discrepancies in model initialization and forcing parameters increases when employing flexible adaptive meshes. This paper introduces a systematic approach to the automated generation of adaptive meshes for geophysical models. This method is efficient in its generation process and readily reproducible, offering robust and consistent adherence to the source data. The proposed approach facilitates research in complex multi-scale geophysical domains, which would be challenging using existing methods. A simulation of monthly mean currents was carried out as a case study in the Gulf of Thailand. Results revealed that the simulated current circulations agreed with the observation. Examples of its application in various ongoing geophysical modeling endeavors illustrate its effectiveness.

Serra Geral Group plumbing system and 3D geological framework in Morungava region, southern Paraná–Etendeka LIP (Brazil): Combining 3D geologic and magnetic models

A coupled 3D geophysical–geological model was constructed by integrating aeromagnetic data and a prior 3D geological model of the Morungava region (Araújo et al., 2023 [manuscript submitted for publication]), situated at the southeastern border of the Paraná–Etendeka large igneous province (LIP) in Brazil. Aeromagnetic data interpretation and modeling (qualitative and semi-quantitative interpretation, susceptibility inversion, forward modeling, and magnetic vector inversion (MVI)), along with magnetic susceptibility data, complemented understanding of the Serra Geral Group feeder system in the subsurface (spatial distribution, depth, and geometry) and illuminated the crustal framework at different depths. We recognized three major NE-elongated geophysical domains (NW, Central, and SE), which were interpreted as basement compartments: the Tijucas, Pelotas, and Jaguarão terranes. The final integrated 3D geophysical–geological model encompasses the stratigraphic framework and the Serra Geral Group plumbing system in the study area, that comprises: two dike systems, four subvolcanic complexes with associated nested sills, and two intrusive ring complexes. This is the first time that these aeromagnetic data have been combined with borehole and 3D geological models.

Energy ratio response at the interface of elastic and dual-porous thermoelastic half-spaces

The present study delves into the intricate examination of energy distribution inherent in plane waves interfacing with an elastic half-space and a thermoelastic half-space characterized by a dual porosity framework. Employing the memory-dependent dual-phase-lag (DPL) hyperbolic two-temperature (H2T) thermoelastic paradigm, the investigation encompasses various incident wave types. The governing equations, rendered in a non-dimensional format, are meticulously addressed by applying the rigorous technique of eigenmode analysis. The intricate energy ratios are meticulously ascertained through the judicious imposition of boundary conditions and the discerning employment of reflection and transmission coefficients. Graphical representations have been exhibited, elucidating the effects of diverse parameters on distinct energy ratios within crystalline structures akin to magnesium materials. These parameters encompass but are not confined to the H2T paradigm, the absence of the two-temperature influence, the classical two-temperature approach, memory effects, and a spectrum of distinct kernel functions. The proposed model emanates cross-disciplinary utility, traversing the domains of seismology, acoustics, optics, materials science, structural engineering, and geophysics.

Machine Learning Framework with Feature Importance Interpretation for Discharge Estimation: A Case Study in Huitanggou Sluice Hydrological Station, China

Accurate and reliable discharge estimation plays an important role in water resource management as well as downstream applications such as ecosystem conservation and flood control. Recently, data-driven machine learning (ML) techniques showed seemingly insurmountable performance in runoff forecasting and other geophysical domains, but they still need to be improved in terms of reliability and interpretability. In this study, focusing on discharge estimation and management, we developed an ML-based framework and applied it to the Huitanggou sluice hydrological station in Anhui Province, China. The framework contains two ML algorithms, the ensemble learning random forest (ELRF) and the ensemble learning gradient boosting decision tree (ELGBDT). The SHapley Additive exPlanation (SHAP) was introduced into our framework to interpret the impact of the model features. In our framework, the correlation analysis of the dataset can provide feature information for modeling, and the quartile method was utilized to solve the outlier problem of the dataset. The Bayesian optimization algorithm was adopted to optimize the hyperparameters of the ensemble ML models. The ensemble ML models are further compared with the traditional stage–discharge rating curve (SDRC) method and the single ML model. The results show that the estimation performance of the ensemble ML models is superior to that of the SDRC and the single ML model. In addition, an analysis of the discharge estimation without considering the flow state was performed. This analysis reveals that the ensemble ML models have strong adaptability. The ensemble ML models accurately estimate the discharge, with a coefficient of determination of 0.963, a root mean squared error of 31.268, and a coefficient of correlation of 0.984. Our framework can prove helpful to improve the efficiency of short-term hydrological estimation and simultaneously provide the interpretation of the impact of the hydrological features on estimation results.

Tectonic Implications for the Gamburtsev Subglacial Mountains, East Antarctica, from Airborne Gravity and Magnetic Data

The Gamburtsev Subglacial Mountains (GSMs) in the interior East Antarctic Craton are entirely buried under the massive East Antarctic ice sheet, with a ~50–60 km thick crust and ~200 km thick lithosphere, but little is known of the crustal structure and uplift mechanism. Here, we use airborne gravity and aeromagnetic anomalies for characteristic analysis and inverse calculations. The gravity and magnetic images show three distinct geophysical domains. Based on the gravity anomalies, a dense lower crustal root is modelled to underlie the GSMs, which may have formed by underplating during the continental collision of Antarctica and India. The high frequency linear magnetic characteristics parallel to the suture zone suggest that the upper crustal architecture is dominated by thrusts, consisting of a large transpressional fault system with a trailing contractional imbricate fan. A 2D model along the seismic profile is created to investigate the crustal architecture of the GSMs with the aid of depth to magnetic source estimates. Combined with the calculated crustal geometry and physical properties and the geological background of East Antarctica, a new evolutionary model is proposed, suggesting that the GSMs are underlain by part of a Pan-African age advancing accretionary orogen superimposed on Precambrian basement.

Aerogeophysical systematics applied to the geological reconnaissance of the Eastern Pernambuco-Alagoas Domain, Borborema Province: The Ipojuca-Atalaia Batholith

Over the past few decades, geological and geophysical studies in the Borborema Province (NE Brazil) have evolved considerably, especially in the North and Central subprovinces. However, the Pernambuco-Alagoas Domain, inserted in the South subprovince, does not have, up to now, detailed geophysical and geological studies, mainly due to a thick soil profile, which make difficulty the geological survey in the region. The aerogeophysical study of an area located in the Ipojuca-Atalaia Batholith, Eastern part of the Pernambuco-Alagoas Domain allowed the delimitation of the lithogeophysical and magnetic geophysical domains, main directions of the lineaments, main shear zones, and their behavior in depth through the upward continuation and the Euler Deconvolution. The set of integrated magnetometric data revealed that the region was intensely deformed by a set of transcurrent shear zones of NE-SW direction. Aerogammaspectrometric data enabled the improvement of the geological mapping (1) of the Western part of the Ipojuca-Atalaia Batholith granitic plutons and gneisses and (2) of the limits of the batholith with the adjoining crustal sub-domains. The integration of the whole set of aero magnetometric and aero gammaspectrometric data also provides a basis for a better understanding of the tectonic evolution of the studied area and the Ipojuca-Atalaia Batholith.

Characteristics of elastic wave dispersion and attenuation induced by microcracks in complex anisotropic media

AbstractThe mechanism of dispersion and attenuation induced by fluid flow among pores and microcracks in rocks is an important research topic in geophysical domain. A generalised frequency-dependent fourth-rank tensor is proposed and derived herein by combining Sayers's discontinuity tensor formula and Gurevich's squirt flow model. Furthermore, a proposed method for establishing a cracked model with cracks embedded in a transversely isotropic (TI) background medium is developed. Based on the new formulation, we investigate the characteristics of dispersion, attenuation and azimuthal anisotropy of three commonly encountered vertical crack distributions, including aligned cracks, monoclinic cracks and cracks with partial random orientations. We validate the developed model by comparing its predictions with those of the classic anisotropic squirt flow model for an aligned crack. The numerical analyses indicate that the azimuth is independent of frequency when the maximum attenuation is observed for all three crack distributions. In a low-frequency range in the case of an anisotropic background, the attenuation of the qP-wave is inversely proportional to velocity, whereas the attenuation of the qSV-wave is proportional to velocity. In addition, the inherent anisotropy of the rock does not significantly affect the dispersion and attenuation owing to squirt flow. Finally, to investigate the applicability of the theory, we model laboratory data of a synthetic porous sandstone with aligned cracks. Overall, the models agree well with laboratory data. The complex characteristics determined through this study may be useful for the seismic characterisation of fractured reservoirs.

Citizen Scientists Conduct Distributed Doppler Measurement for Ionospheric Remote Sensing

Doppler shift measurement using time standard stations as passive radar beacons is well-established as a means of estimating virtual ionospheric height. A community science experiment in distributed Doppler shift measurement was conducted in October 2019 using the time station WWV, on the event of that station’s centennial. Participants were asked to collect Doppler shift data from the WWV 5-MHz carrier via the open-source software program fldigi. This experiment garnered participation from stations across the country, demonstrating considerable volunteer interest: 45 recordings of WWV’s 5-MHz beacon were collected. The novel element of this study is the use of distributed low-fidelity sensors in this geophysical domain, and the robust participation of the amateur radio community was enabled by inexpensive and readily available instrumentation. In this letter, we present an initial correlation analysis of the resultant data and discuss its implications for future long-term distributed Doppler networks. The data collected are in good agreement and, when examined together, offer some insights into regional trends. Despite the variety of equipment used by the amateur community, this community science approach shows promise for addressing the problem of undersampling in the geospace system.

Forearc Crustal Structure of Ecuador Revealed by Gravity and Aeromagnetic Anomalies and Their Geodynamic Implications

AbstractAlong the Western Cordillera of Ecuador, fault-bounded ophiolites derived from the Late Cretaceous Caribbean Large Igneous Province (CLIP) have provided key petrotectonic indicators that outline the nature and the mechanism of continental growth in this region. However, most of the forearc basement across Western Ecuador is buried under sediments impairing its crustal structure understanding. Here, we propose a first crustal model throughout the spectral analysis of gravity and aeromagnetic data, constrained by observations made both at the surface and at the subsurface. Three main geophysical domains, within the North Andean Sliver in Western Ecuador, have been defined based on spectral analysis and augmented by 2D forward models. An outer domain, characterized by magnetic anomalies associated with mafic rocks, coincides with evidence of a split intraoceanic arc system. An inner domain is governed by long-wavelength mid to deep crust-sourced gravity and magnetic anomalies possibly evidencing the root of a paleoisland arc and the residuum of a partial melting event with subsequent associated serpentinization, the latest possibly associated with an obduction process during the middle Eocene-Oligocene. In addition, our model supports the presence of a lithospheric vertical tear fault, herein the southern suture domain, inherited from an oblique arc-continent interaction. Our interpretation also brings new insights and constraints on the early geodynamic evolution of the Ecuadorian forearc and provides evidence on the structural style and preservation potential of the forearc basement, most likely the roots of a mature island arc built within an oceanic plateau.

Swell-noise attenuation: A deep learning approach

Noise attenuation for ordinary images using machine learning technology has achieved great success in the computer vision field. However, directly applying these models to seismic data would not be effective since the evaluation criteria from the geophysical domain require a high-quality visualized image and the ability to maintain original seismic signals from the contaminated wavelets. This paper introduces an approach equipped with a specially designed deep learning model that can effectively attenuate swell noise with different intensities and characteristics from shot gathers with a relatively simple workflow applicable to marine seismic data sets. Three significant benefits are introduced from the proposed deep learning model. First, our deep learning model doesn't need to consume a pure swell-noise model. Instead, a contaminated swell-noise model derived from field data sets (which may contain other noises or primary signals) can be used for training. Second, inspired by the conventional algorithm for coherent noise attenuation, our neural network model is designed to learn and detect the swell noise rather than inferring the attenuated seismic data. Third, several comparisons (signal-to-noise ratio, mean squared error, and intensities of residual swell noises) indicate that the deep learning approach has the capability to remove swell noise without harming the primary signals. The proposed deep learning-based approach can be considered as an alternative approach that combines and takes advantage of both the conventional and data-driven method to better serve swell-noise attenuation. The comparable results also indicate that the deep learning method has strong potential to solve other coherent noise-attenuation tasks for seismic data.

A Laboratory Investigation of Spume Generation in High Winds for Fresh and Seawater

AbstractGiven spume's role in mediating air‐sea exchange at the base of tropical cyclones or other storm events, the focus of studies on spray dynamics has been within the marine environment. In contrast, spume production in nonseawater bodies has been underexplored and potential differences between sea and freshwater are neglected. The laboratory remains the primary means for directly observing spray processes near the surface because of the challenges to making robust field measurements. There is no standardization on the water type used for these experiments, and the effect this has on the generation process is unknown. This adds uncertainty in our ability to make physically realistic spume generation functions that are ultimately applied to the geophysical domain. We have conducted a laboratory experiment that aims to address this simple, yet overlooked, question of whether water type impacts the spume droplet concentration entrained in the air flow above actively breaking waves. We compared directly imaged concentrations for fresh and seawater droplets produced in 10‐m equivalent winds from 36–54 m/s. Substantially higher concentrations of seawater spume were observed, as compared to freshwater across all particle sizes and wind speeds. The seawater particles' vertical distribution was concentrated near the surface, whereas the freshwater droplets were more uniformly distributed. Our statistical analysis of these findings suggests significant differences in the size‐ and height‐dependent distributions response to increased wind forcing between fresh and seawater. These unexpected findings suggest an unanticipated role of the source water physiochemical properties on the spume generation mechanism.

Crowdsourcing Methods for Data Collection in Geophysics: State of the Art, Issues, and Future Directions

AbstractData are essential in all areas of geophysics. They are used to better understand and manage systems, either directly or via models. Given the complexity and spatiotemporal variability of geophysical systems (e.g., precipitation), a lack of sufficient data is a perennial problem, which is exacerbated by various drivers, such as climate change and urbanization. In recent years, crowdsourcing has become increasingly prominent as a means of supplementing data obtained from more traditional sources, particularly due to its relatively low implementation cost and ability to increase the spatial and/or temporal resolution of data significantly. Given the proliferation of different crowdsourcing methods in geophysics and the promise they have shown, it is timely to assess the state of the art in this field, to identify potential issues and map out a way forward. In this paper, crowdsourcing‐based data acquisition methods that have been used in seven domains of geophysics, including weather, precipitation, air pollution, geography, ecology, surface water, and natural hazard management, are discussed based on a review of 162 papers. In addition, a novel framework for categorizing these methods is introduced and applied to the methods used in the seven domains of geophysics considered in this review. This paper also features a review of 93 papers dealing with issues that are common to data acquisition methods in different domains of geophysics, including the management of crowdsourcing projects, data quality, data processing, and data privacy. In each of these areas, the current status is discussed and challenges and future directions are outlined.

Deep crustal framework of the Borborema Province, NE Brazil, derived from gravity and magnetic data

The Borborema Province BP (NE Brazil) consists of a complex rock mosaic composed mainly by Proterozoic metasedimentary belts that amalgamate Archean-to-Paleoproterozoic gneiss-migmatite complexes. It is a key region to understand the West Gondwana amalgamation, during the Pan-African/Brasiliano orogeny because it is an important portion of the orogen located between the São Francisco-Congo and West African cratons. We present the deep-rooted crustal framework of the BP interpreting the lateral contrasts of density and magnetization using the first available regional coverage of gravity and aeromagnetic data. The external boundaries of the BP having deep-rooted crustal significance are the Transbrasiliano shear zone, to the west, and the limit with the São Francisco craton, to the south. The latter limit is marked by a gravity anomaly which is the typical gravity signature of collisional sutures. Inside the BP crustal block, the Pernambuco, Patos, and Jaguaribe shear zones are identified as the major structures, based on termination and/or truncation criteria of geophysical anomalies. The three shear zones correspond to geophysical lineaments which conform with the Transbrasiliano shear zone, forming a single splay that opens to the northeast/east direction. The external boundaries and major shear zones divide the BP crustal block into four internal major domains of contrasting geophysical characteristics, namely the Southern, Transversal Zone, Rio Grande do Norte, and Ceará geophysical domains in analogy with the division based on surface geology. However, compared with the delimitations based on surface geology, there are three differences: the Médio Coreau belt is not positioned over the BP crustal block, a portion of the Parnaíba basin baseament should be included in the BP crustal block, and the basement beneath the folded-and-thrusted metasedimentary rocks of the Casa Nova Group (which form the nappes of the Riacho do Pontal belt) is part of the São Francisco craton crustal block. A subdivision of each major domain is also presented. Of special relevance is a pattern of alternate-polarity, quasi-parallel aligned geophysical anomalies present in the Transversal Zone domain, suggesting a clear alternation of high-density/high-susceptibility with low-density/low-susceptibility deep-rooted crustal subdomains. This geophysical pattern is compatible with a tectonic model of terrane collage.

The spectral cell method in nonlinear earthquake modeling

This study examines the applicability of the spectral cell method (SCM) to compute the nonlinear earthquake response of complex basins. SCM combines fictitious-domain concepts with the spectral-version of the finite element method to solve the wave equations in heterogeneous geophysical domains. Nonlinear behavior is considered by implementing the Mohr–Coulomb and Drucker–Prager yielding criteria. We illustrate the performance of SCM with numerical examples of nonlinear basins exhibiting physically and computationally challenging conditions. The numerical experiments are benchmarked with results from overkill solutions, and using MIDAS GTS NX, a finite element software for geotechnical applications. Our findings show good agreement between the two sets of results. Traditional spectral elements implementations allow points per wavelength as low as PPW = 4.5 for high-order polynomials. Our findings show that in the presence of nonlinearity, high-order polynomials ( $$p \ge 3$$ ) require mesh resolutions above of $$PPW \ge $$ 10 to ensure displacement errors below 10%.

An implicit wetting and drying approach for non-hydrostatic baroclinic flows in high aspect ratio domains

A new approach to modelling free surface flows is developed that enables, for the first time, 3D consistent non-hydrostatic baroclinic physics that wets and dries in the large aspect ratio spatial domains that characterise geophysical systems. This is key in the integration of physical models to permit seamless simulation in a single consistent arbitrarily unstructured multiscale and multi-physics dynamical model. A high order continuum representation is achieved through a general Galerkin finite element formulation that guarantees local and global mass conservation, and consistent tracer advection. A flexible spatial discretisation permits conforming domain bounds and a variable spatial resolution, whilst atypical use of fully implicit time integration ensures computational efficiency. Notably this brings the natural inclusion of non-hydrostatic baroclinic physics and a consideration of vertical inertia to flood modelling in the full 3D domain. This has application in improving modelling of inundation processes in geophysical domains, where dynamics proceeds over a large range of horizontal extents relative to vertical resolution, such as in the evolution of a tsunami, or in urban environments containing complex geometric structures at a range of scales.

Geologically constrained 2D and 3D airborne EM inversion through cross-gradient regularization and multi-grid efficiency

With a goal of increasing the geological reliability of single and joint domain inversion, including those set in rugged terrain, we present an expanded scope for cross-gradient regularized inversion. The basic application covers the usual structural similarity objective — comparing the gradient fields of distinct property volumes derived from different geophysical domains — but a particular advantage comes when including gradients derived a priori, from geology or any ancillary property set, providing reference gradient control during single or joint inversions. In the first example, straightforward cross-gradient joint inversion of synthetic datasets of airborne EM (AEM) and airborne gravity-gradiometry (AGG) improves both the lateral and vertical definition of closely adjacent but distinct bodies. Two further AEM examples include surface and subsurface geology in the cross-gradient inversion; a) complex foothills setting, and b) buried massive sulphide. Both outputs demonstrate a marked improvement in interpretability over the standard smooth model approach.

Application of Musical Information Retrieval (MIR) Techniques to Seismic Facies Classification. Examples in Hydrocarbon Exploration

In this paper, we introduce a novel approach for automatic pattern recognition and classification of geophysical data based on digital music technology. We import and apply in the geophysical domain the same approaches commonly used for Musical Information Retrieval (MIR). After accurate conversion from geophysical formats (example: SEG-Y) to musical formats (example: Musical Instrument Digital Interface, or briefly MIDI), we extract musical features from the converted data. These can be single-valued attributes, such as pitch and sound intensity, or multi-valued attributes, such as pitch histograms, melodic, harmonic and rhythmic paths. Using a real data set, we show that these musical features can be diagnostic for seismic facies classification in a complex exploration area. They can be complementary with respect to “conventional” seismic attributes. Using a supervised machine learning approach based on the k-Nearest Neighbors algorithm and on Automatic Neural Networks, we classify three gas-bearing channels. The good performance of our classification approach is confirmed by borehole data available in the same area.

A Global Integration Platform for Optimizing Cooperative Modeling and Simultaneous Joint Inversion of Multi-domain Geophysical Data

This paper reviews the theoretical aspects and the practical issues of different types of geophysical integration approaches. Moreover it shows how these approaches can be combined and optimized into the same platform. We discuss both cooperative modeling and Simultaneous Joint Inversion (SJI) as complementary methods for integration of multi-domain geophysical data: these data can be collected at surface (seismic, electromagnetic, gravity) as well as in borehole (composite well logs). The main intrinsic difficulties of any SJI approach are the high computational requirements, the non-uniqueness of the final models, the proper choice of the relations between the different geophysical domains, the quantitative evaluation of reliability indicators. In order to face efficiently all these problems we propose and describe here a “systemic approach”: the algorithms of modeling and SJI are merged with an integration architecture that permits the selection of workflows and links between different algorithms, the management of data and models coming from different domains, the smart visualization of partial and final results. This Quantitative Integration System (QUIS) has been implemented into a complex software and hardware platform, comprising many advanced codes working in cooperation and running on powerful computer clusters. The paper is divided into two main parts. First we discuss the theoretical formulation of SJI and the key concepts of the QUIS platform. In the second part we present a synthetic SJI test and a case history of QUIS application to a real exploration problem.

Double Diffusion in Saline Powell Lake, British Columbia

Abstract Powell Lake contains a deep layer of relic seawater separated from the ocean since the last ice age. Permanently stratified and geothermally heated from below, this deep layer is an isolated geophysical domain suitable for studying double-diffusive convection. High-resolution CTD and microstructure measurements show several double-diffusive staircases (Rρ = 1.6 to 6) in the deep water, separated vertically by smooth high-gradient regions with much larger density ratios. The lowest staircase contains steps that are laterally coherent on the basin scale and have a well-defined vertical structure. On average, temperature steps in this staircase are 4 mK, salinity steps are 2 mg kg−1, and mixed layer heights are 70 cm. The CTD is capable of measuring bulk characteristics of the staircase in both temperature and salinity. Microstructure measurements are limited to temperature alone, but resolve the maximum temperature gradients in the center of selected laminar interfaces. Two different algorithms for characterizing the staircase are compared. Consistent estimates of the steady-state heat flux (27 mW m−2) are obtained from measurements above and below the staircase, as well as from microstructure measurements in the center of smooth interfaces. Estimates obtained from bulk interface gradients underestimate the steady-state flux by nearly a factor of 2. The mean flux calculated using a standard 4/3 flux law parameterization agrees well with the independent estimates, but inconsistencies between the parameterization and the observations remain. These inconsistencies are examined by comparing the underlying scaling relationship to the measurements.

Structural framework of the Jaibaras Rift, Brazil, based on geophysical data

The Cambro-Ordovician Jaibaras Rift is a NE–SW trending elongated feature, controlled by the Transbrasiliano lineament, locally known as Sobral-Pedro II shear zone (SPIISZ). An integrated study of geophysical data (gammaspectrometry, magnetometry and gravimetry) was undertaken in the Jaibaras Rift area, between Ceará Central (CCD) and Médio Coreaú domains (MCD), northwest Borborema Province. Geophysical data were interpreted qualitatively and quantitatively in order to understand the tectono-magmatic relations and rift formation based on the main geophysical lineaments, source geometry and depth, and separation of geophysical domains. In addition, a 2D gravity model was generated. The results show a structural partition characterized by NE–SW lineaments and E–W inflexions, where CCD presents a relatively mild magnetic field, whilst the MCD field is more disturbed. The Jaibaras Rift is characterized by positive magnetic and gravity anomalies. The SPIISZ, which corresponds to the SE fault edge of the Jaibaras Rift, is marked by strong magnetic dipoles and strong gravity gradients in the profile, showing the deep character of the Transbrasiliano lineament in the region. The Café-Ipueiras fault, at the NW edge of the rift, is well marked in gravity profiles, but displays low contrast of the magnetic field. Interpretation of the gravimetric anomaly map allowed to recognizing the main NE–SW axis, with alternation of maxima and minima in MCD. A regional gravity gradient reveals significant lateral density variation between the MCD and CCD perpendicular to the SPIISZ, emphasizing it as a main continental suture zone between crustal blocks.