Earthquake rupture is a spatially extended, time-dependent process governed by the interplay between rupture kinematics and energy partitioning along the fault. Although kinematic source models and energetic formulations are widely used, their local physical consistency is typically not enforced explicitly. Here, a physical–mathematical framework is introduced that links rupture geometry, kinematic fields, and local energy balance within a unified spatial–temporal–energetic description of extended seismic sources. Rupture propagation is described through a spatially defined rupture-time field, from which rupture-front velocity is derived as the inverse gradient of rupture time. Local energy consistency is imposed through a balance between energy release rate, fracture energy, and radiated energy, leading to a formulation in which rupture velocity and radiative efficiency are locally constrained by a common energy balance. Within this framework, kinematic rupture models can be interpreted as implicitly defining a local energy budget. A synthetic diagnostic example demonstrates that not all kinematically admissible rupture-time fields correspond to energetically plausible configurations, and that strongly heterogeneous rupture-velocity patterns may imply violations of local energy-balance conditions. The proposed formulation does not provide direct constraints for inversion, but establishes necessary conditions for physical admissibility that are independent of specific constitutive laws or numerical implementations. By making explicit the energetic assumptions embedded in kinematic descriptions, this framework provides a physically grounded basis for interpreting rupture heterogeneity, radiated energy variability, and source-process observations.
Geotechnical investigations have traditionally relied on invasive methods, such as boreholes and laboratory tests. However, these techniques can be time-consuming, expensive and spatially limited, often resulting in discontinuous subsurface characterisation that fails to capture the full extent of soil heterogeneity. Geophysical methods are becoming increasingly integrated into conventional geotechnical investigations to overcome these spatial and economic constraints. This review examines how seismic, electrical resistivity and electromagnetic surveys provide rapid, nondestructive and spatially continuous subsurface data that can be used to infer geotechnical information across a range of shallow infrastructure and environmental applications, typically within the upper 30 m of the subsurface, at site-specific scale. Methods such as multichannel analysis of surface waves (MASW) estimate shear-wave velocity profiles, which can be related to soil stiffness and small-strain shear modulus through appropriate constitutive assumptions and site-specific calibration. Electrical resistivity tomography (ERT) is well suited to mapping moisture content distributions and detecting seepage anomalies in embankments and slopes. A key finding of this review is that the reliability of geophysical–geotechnical correlations is strongly parameter-dependent: Relationships grounded in physical theory, such as that between shear-wave velocity and small-strain shear modulus, are more robust and transferable than empirical correlations such as those between resistivity and SPT-N values, which tend to be highly site-specific. In all cases, reliability depends on integration with complementary geophysical methods and calibration against direct geotechnical measurements, since soil heterogeneity and environmental conditions can make interpretation ambiguous. Advanced data fusion approaches, including belief function theory and geostatistical interpolation, show practical potential for combining heterogeneous datasets and managing spatial uncertainty. Emerging techniques such as machine learning and Full waveform inversion (FWI) offer further possibilities for quantitative parameter estimation, though their routine application remains constrained by computational demands and the current lack of standardised field validation datasets. This review identifies current knowledge gaps and outlines directions for developing more reliable, quantitative frameworks for geophysical–geotechnical integration in infrastructure assessment and environmental applications.
This study was conducted in the district of Perma, in northwestern Benin, in the department of Atacora. This region of Precambrian crystalline bedrock is known for its gold potential, which is exploited using artisanal and semi-industrial methods. The use of mercury and cyanide has serious repercussions on soil and water, mainly due to acid mine drainage (AMD). The main objective of this study is to characterize AMD associated with gold mining in Perma using magnetic methods and electrical resistivity tomography. Four mining sites were studied, including two alluvial sites (Perma-Centre and Perma-Koka) and two vein sites (Gnagnamou and Koussigou Montagne). The magnetic data show that AMD is stored in the bed of the Perma River at the alluvial sites, with a total magnetic field intensity varying between 33,337.0 and 33,360.8 nT at Perma-Centre and 33,429.2 and 33,443.5 nT at Perma-Koka. At the vein sites, the AMD is stored in fractures and galleries created by gold miners, with magnetic intensity varying between 33,434.7 and 33,446.2 nT at Gnagnamou and 33,437.4 and 33,470.7 nT at Koussigou Montagne. These magnetic data guided the choice of profiles for ERT section acquisition. ERT data show that resistivities at the alluvial sites range from 114 to 10,121 Ωm at Perma-Centre and from 45.4 to 7967 Ωm at Perma-Koka. The AMD, with resistivity ranging from 199 to 402 Ωm, infiltrates the riverbed to a depth of 30 m at Perma-Centre and 15 m at Perma-Koka and circulates in the gravel. At the vein sites, resistivities vary between 655 and 47,180 Ωm at Koussigou Montagne and between 2181 and 134,398 Ωm at Gnagnamou. The AMD flows toward depressions and accumulates in fractures, sometimes reaching depths of more than 40 m. These variations in resistivity confirm the differentiated impact of the AMD.
Indonesia hosts 331 geothermal prospects with a combined potential of 28,617 MW, yet by the end of 2024, only 13.2% had been developed, highlighting a critical need for improved exploration workflows. In this study, we characterize the subsurface geothermal architecture of the Tiris District (Probolinggo Regency, Lamongan-Argopuro volcanic complex) by integrating dense Bouguer gravity surveying (150 km2) with first horizontal and second vertical derivative analyses and three-dimensional density inversion. Bouguer anomalies range from 39.95 to 80.03 mGal, with highs in the eastern and western sectors and lows in the northwest and south, while derivative maps reveal a network of predominantly NW-SE normal faults that likely channel geothermal fluids. The inversion model uncovers a shallow low-density zone (1.0-1.5 g/cm3) to 0.75-km depth interpreted as fluid conduits, a sandstone reservoir layer (1.5-2.0 g/cm3) at 2-3 km, caprock units (2.0-3.0 g/cm3) at 0.5-2.0 and 3.0-4.0 km, and deep high-density bodies (3.3-4.0 g/cm3) below 4 km corresponding to magmatic heat sources. These findings refine the conceptual model for Tiris, demonstrate the effectiveness of integrated gravity derivatives and inversion in volcanic geothermal exploration, and underscore the region ' s promise for sustainable energy development. By precisely delineating subsurface structures with precision, this work provides critical insights to guide sustainable resource development and targeted drilling strategies in volcanic geothermal systems.
The Ngaound & eacute;r & eacute; area, marked by a complex geodynamic context, is characterized by ancient and recent tectonic activities, as well as intraplate volcanism linked to the Cameroon volcanic line (CVL). Ground magnetic mapping is an effective geophysical tool for detecting hidden faults or fractures and magnetic intrusions. The aim of this study is to investigate the basement of the maar Lake Tizong area in the Adamawa Plateau. Ground magnetic survey and eological field work have been carried out. Geological field work reveals that volcanic and granitic formations cropping out in the study area, and the main brittle structures trend NW-SE. Qualitative and quantitative analyses were performed on magnetic data. Qualitative analysis uses a number of operators and mathematical filters, notably reduction to the equator, regional/residual separation, gradients, analytical signal, and tilt angle derivative. This enabled us to describe the anomalies globally, identify magnetic discontinuities and structures assimilated to fractures and faults, and produce a structural map of the magnetic lineaments. A quantitative analysis involves Euler deconvolution, 2D3/4 modeling, and the source parameter index methods and makes it possible to assess the shapes and depths of the anomaly causative sources. As a result, the qualitative analysis identified several lineament directions, chiefly ESE-WNW, ENE-WSW, NE-SW, and NW-SE assimilated to brittle or ductile deformation. Structures trending NE-SW and ENE-WSW correlate with the regional fault of Ngaound & eacute;r & eacute; and are associated with the regional tectonic of the CVL. It revealed a cluster of solutions with depths greater than 100 m in the Mandjir area. These correspond to new magnetic discontinuities indicating the presence of intrusive bodies in the subsoil. However, NW-SE and WNW-ESE are linked to the major volcanic lava of Ngaound & eacute;r & eacute; and the orientation of Vina River. This work shows the presence of discontinuities favorable for fissural volcanism.
A novel and integrated geophysical approach has been applied at Cascina and Palarzano plains (Abruzzi region, Central Apennines, Italy) to investigate their subsurface structure with particular attention to the faults bounding the basins. Both plains are characterized by the highest magnetic anomaly intensity measured over the Abruzzi region (up to 10 nT). A 3D reconstruction of these small intermontane basins was performed through a magnetic inversion of a high-resolution aeromagnetic survey. The model results and the choice of appropriate parameters used for the magnetic inversion calculations were verified and constrained by other geophysical investigations performed in the plain (e.g., gravimetry, electrical resistivity tomography, seismic waves, and ambient noise measurements). Through this approach, a 3D model of Cascina and Palarzano plains was implemented for the first time. The model reveals, for both plains, a thickness of Quaternary filling of ca. 100 m and a clear half-graben geometry which characterized the Cascina plain.
The Thailand-Myanmar-Malaysia region is characterized by a complex tectonic setting and significant seismic hazard, necessitating a detailed understanding of its crustal and upper mantle structure. This study addresses knowledge gaps in the region's deep lithospheric structure, aiming to elucidate its tectonic evolution and geodynamics. We present high-resolution Rayleigh wave phase velocity maps for the region, derived from ambient noise tomography using continuous seismic data from a dense network of 99 broadband stations. Through the analysis of empirical Green's functions at periods of 10-100 s, we investigate structures ranging from the middle crust to the upper mantle. The phase velocity maps at periods reveal distinct velocity variations that correlate with major tectonic features, such as the Sagaing Fault, the Shan-Thai Terrane, and the Khorat Plateau. Low-velocity anomalies are observed in the West Burma Terrane and the Khorat Plateau, while high-velocity anomalies characterize the Shan-Thai Terrane, Peninsular Thailand, and Peninsular Malaysia. At shorter periods (10-15 s), we observe a clear demarcation between high velocities in the Shan-Thai Terrane and low velocities in the Indo-China Terrane, reflecting significant differences in shallow crustal structure and composition. At longer periods, the phase velocity maps provide evidence for a cold, stable lithospheric mantle beneath the Shan-Thai Terrane and Peninsular Malaysia, and thin, hot lithosphere or upwelling asthenosphere beneath central Myanmar and the Gulf of Thailand. These findings offer new insights into the region's crustal composition, thickness, and tectonic boundaries, contributing to our understanding of Southeast Asia's complex geodynamics and tectonic structure.
This manuscript examines the performance of two ionospheric models, AfriTEC and NeQuick 2, at station BF01 (lat. 12.3714° N, long. −1.5197° W) in Ouagadougou, Burkina Faso, situated in the West African equatorial region. The study is aimed at aiding in selecting an appropriate ionospheric model for this region, where in situ data are scarce. It involves comparing the VTEC values derived from RINEX files obtained at station BF01 with those provided by the two models, AfriTEC and NeQuick 2. Two periods were distinguished: a period of high solar activity (Rz ≥ 50) between 2013 and 2015 and a period of low solar activity (Rz < 50) from 2016 to 2021. The results show that during periods of high solar activity, both models underestimate VTEC with relative differences of up to −60%. However, AfriTEC is closer to the RINEX values during hours of strong sunlight. Between 2016 and 2021, the performance of the models gradually improves, with AfriTEC being more stable and more consistent with the RINEX data, especially during periods of VTEC peak. NeQuick2 performs less well during hours of strong sunshine and at night, with greater deviations from the RINEX data. From this study, it emerges that AfriTEC is the most suitable ionospheric model for predicting VTEC at station BF01.
Total electron content (TEC) is a crucial parameter for monitoring space weather effects, typically obtained from a network of Global Navigation Satellite System (GNSS) receivers. However, the uneven distribution of the available GNSS receivers in East Africa results in limited TEC data coverage. To address this challenge, a novel hybrid approach was introduced that combined the finite element method (FEM) with the ensemble Kalman filter (EnKF) technique to construct detailed vertical total electron content (VTEC) maps from limited observations. This innovative method enhanced the spatial and temporal resolution of TEC maps, offering a significant improvement over existing methods by capturing local VTEC variations with higher precision. The study investigated VTEC characteristics over East Africa during high (2014) and low (2018) solar activity years, revealing notable diurnal and seasonal VTEC variations, with peak values during equinoxes and significant disruptions during geomagnetic storms. The developed VTEC maps were validated against GNSS receiver data, showing a strong correlation (0.98–0.99) with actual measurements. This suggested that the FEM-EnKF approach provides a reliable and accurate tool for estimating VTEC over the East African region, particularly in areas with sparse data coverage, thereby supporting global navigation and space weather monitoring applications.
The characterization of Lamu offshore reservoirs remains limited due to the absence of integrated studies combining petrophysical analysis and rock physics modeling. This study aims to enhance reservoir characterization, reduce exploration risks, and provide a framework for similar geological settings. Log data from three wells were analyzed to determine key petrophysical properties and evaluate rock physics models for lithology and fluid discrimination. Reservoir zones were delineated based on petrophysical parameters, including clay volume, porosity, hydrocarbon saturation, and gamma ray and resistivity responses. The selected reservoirs exhibited favorable characteristics, with low shale volume (0.07–0.26), high effective porosity (0.12–0.25), low water saturation (0.23–0.56), and a net thickness (18.95–43.22 m). Rock physics cross‐plots (mu‐rho vs. density, acoustic impedance vs. lambda‐rho, and V p / V s ratio vs. acoustic impedance, among others) effectively distinguished hydrocarbon‐bearing zones from brine‐saturated sands and shales. Color‐coded cross‐plots further validated fluid discrimination, showing low water saturation and gamma ray values with high porosity in hydrocarbon zones. Gassmann fluid substitution analysis confirmed that replacing water with hydrocarbons significantly reduced density and had a more pronounced effect on compressional velocity than shear velocity. These findings highlight an integrated approach to minimizing hydrocarbon exploration risks, particularly in avoiding dry wells, and offer valuable insights for future exploration efforts in Lamu offshore and similar basins.
Joint surface and borehole seismic are a 3D surface-and-borehole seismic exploration method of the simultaneous acquisition of onshore or offshore 3D seismic and VSP (vertical seismic profiling) data using the same sources. When acquiring surface 2D or 3D seismic data in the field, simultaneously acquired 2D or 3D distributed acoustic sensing VSP or DAS-VSP (Distributed Acoustic Sensing-Vertical Seismic Profiling) data can provide full well high-resolution structural images around the borehole and enhance surface 2D or 3D seismic data processing significantly. This paper describes the imaging processing of the 3D DAS-VSP data from 13 wells jointly acquired with a high-density OBN (Ocean Bottom Node) data acquisition project. Apart from the conventional processing steps of 3D VSP data, the deblending processing of the blended acquired multiwell 3D DAS-VSP data using multiple airgun sources, special ringing noise removal procedure, joint domain full waveform inversion (JDFWI) for velocity model update, and one-way wave equation multiple migration (OWEMM) method were used to generate final 3D DAS-VSP data imaging. The results provided good quality structural imaging in a relatively large subsurface area around the 13 wells.
This present article was written to analyze the variability of the diurnal profiles of the critical foF2 frequencies in the light of solar radiation based on in situ measurements of the ionosonde stations of Dakar (latitude 14.8° N, longitude 342.6° E) and Ouagadougou (latitude 12.5° N, longitude 358.5° E), respectively, for Sunspot Cycles 21 and 22. The objective being to deduce interpretations in terms of propensity to occur on the five profiles B, M, R, D, and P referenced to occurrence between the latitudes of 20° N and 20° S. Thus, on the analyses of conjunctions in phases or in phase shift observed in the variation of the sunspot cycle (VSC) and monthly foF2 frequencies (MFVs), we will note the following: (1) during periods of geomagnetic calm, (a) a propensity for the formation of the R profile during the growth phases of the solar cycle and during the periods from the solstices to the equinoxes and this is due to the conjunction in the growth–growth phase between VSC and MFV; (b) a propensity for the formation of the M profile during the waning phases of the solar cycle and during the periods from the equinoxes to the solstices and this is due to the conjunction in the waning–decaying phase between VSC and MFV; (c) a propensity for the formation of profiles B, D, and P on the one hand during the growth phases of the solar cycle and during the periods from the equinoxes to the solstices and on the other hand during the waning phases of the solar cycle and during the periods from the solstices to the equinoxes and all these are due to the nonconjunction in the phase between VSC and MFV. It therefore appears that out of the 16 possible propensities for profile formations, the R and M profiles are each counted for 12.5%. Profiles B, P, and D each counted 25%. (2) During periods of geomagnetic disturbances, notably by SFEs, CMEs, or ionization losses, a profile can transform into one or other of the other four profiles. Finally, as an importance or application of this study, we note that (a) foF2 contributes more to the good knowledge of the ionosphere; (b) using the diurnal profiles of foF2, we could a priori identify periods of lulls in radio or satellite transmission; (c) by induction, we could count the solar flares during the day; and (d) the proposed mathematical model is a basic tool for analyzing foF2 variability.
This study presents a three‐dimensional shear wave velocity (Vs) model and azimuthal anisotropy of the crust beneath northern and central Thailand derived from ambient noise tomography. Continuous seismic data from 99 broadband stations across Southeast Asia were processed to extract Rayleigh wave phase velocity dispersion curves. These curves were then used in a direct joint inversion for both isotropic Vs perturbations and azimuthal anisotropy at depths of 15–35 km. The inversion was initialized with a local 1D velocity model specifically derived for northern Thailand. Results reveal significant lateral heterogeneities in crustal structure, with Vs ranging from 3.615 to 3.675 km/s at 15–20 km depth to 3.650 to 3.720 km/s at 30–35 km depth across the study area. A prominent high‐velocity anomaly (Vs > 3.675 km/s at 15–20 km depth, Vs > 3.745 km/s at 20–30 km depth, and Vs > 3.720 km/s at 30–35 km depth) is observed in the northwestern sector (18.5°–19.5° N, 98°–101° E), corresponding to the Shan‐Thai terrane. The velocity contrast between the Shan‐Thai and Indo‐China terranes is delineated by a lateral velocity gradient, with the Shan‐Thai Terrane consistently exhibiting higher velocities throughout the investigated depth range. Azimuthal anisotropy patterns show complex variations, with a prominent NW‐SE trend in fast polarization directions in northern Thailand, consistent across all depth ranges. The strongest anisotropy is observed in the northern Thailand, coinciding with high‐velocity zones. The spatial correspondence between present‐day surface kinematics, as recorded by GPS measurements, and crustal anisotropic fabric suggests a coherent deformation pattern that extends through multiple crustal levels, with pronounced expressions along terrane boundaries.
Located within the Adamaoua‐Yadé domain in Cameroon, the Lom volcano–sedimentary formation represents a central component of the Central African Pan‐African Belt, which emerged during the Pan‐African orogeny between 600 and 500 Ma. The complexity of tectonic processes in this area has resulted in geological structures favorable to the presence of gold mineralization. The dynamic geological environment, characterized by detrital deposits and intense tectonic phases, is illustrated by the deformed and metamorphosed metasedimentary and metavolcanic rocks of the Lom Formation. The accumulation of precious minerals such as gold and diamonds is facilitated by optimal stratigraphic conditions, including basalt, tuffs, quartz‐bearing sediments, schists, and conglomerates. These economically significant resources are closely associated with regional faults and ENE‐WSW‐oriented shear zones, which promote the circulation of mineralizing hydrothermal fluids. A geophysical study was conducted in the village of Bindiba, a locality situated within this geological formation, not far from a semimechanized gold mining operation. The study is aimed at establishing and proposing a modeling of potential mineralized targets. The geophysical study combines the use of electric resistivity tomography (ERT) and induced polarization (IP). The acquisition includes 17 parallel electric tomography lines in a Schlumberger configuration. The acquired data allowed the production of 2D inversion models, which were then interpolated to generate block models and pseudo‐3D isosurface models of potential mineralizations. The correlation of geological information and pseudo‐3D isosurface models allowed the characterization of the existence of three polarizable bodies, marked by the presence of sulfides, with high chargeability values ( M ≥ 30 mV/V). One of these bodies, presenting a strong chargeability, correlated to a low resistivity (Rho < 900 Ωm), is observed in the center of the study area. This body presents its roof at an average depth of 17 m, with a lateral extension and a NE‐SW orientation consistent with the general orientation of the main tectonic lines of the region. The two other polarizable bodies were identified near the surface, both in the center and in the north with average depths of 8 and 15 m, respectively. They both present a fairly good correlation with high resistivity values (Rho ≥ 5500 Ωm), which could characterize probable silicification zones.
The oil and gas industry relies heavily on inverse geostatistical modeling to predict static reservoir properties that influence hydrocarbon accumulation and flow. However, these methods face significant challenges due to sparse sampling and the inability to capture reservoir variability beyond boreholes. Geostatistical techniques typically depend on borehole data, which represent only a small fraction of the total reservoir volume. The large distances between boreholes further hinder the ability to achieve reliable and accurate predictions. An innovative approach in numerical forward modeling, the stratigraphic-structural forward modeling (SSFM) technique, offers an alternative or complementary workflow for modeling facies and property distribution in static reservoir models. The SSFM quantitatively integrates sedimentation and deformation processes in basins, grounded in the physics of basin formation, infill, and sedimentary architecture. By translating conceptual geological models into cellular geological volumes, SSFM requires minimal borehole and seismic data for validation. This review traces the historical evolution of various numerical techniques, with particular emphasis on the advancements and limitations of SSFM. However, these limitations present opportunities for guiding future research, fostering development in the field, and extending the application of SSFM techniques beyond hydrocarbon exploration. Understanding and addressing SSFM’s limitations is essential to optimizing and enhancing its effectiveness within the industry.
The present work focuses on the variability of the magnetospheric convection electric field (MCEF) during geomagnetic storms generated by coronal mass ejections (CMEs). The aim of the study was to analyze the response of the MCEF to geoeffective CMEs occurring during the maximum phase of Solar Cycle 24. A total of eight storms were selected on the basis of their intensity with respect to the Dst (disturbance storm time) and Kp (planetary geomagnetic index) indices. We examined the variations in solar wind parameters (V SW (solar wind speed), P SW (plasma pressure), and interplanetary magnetic field (IMF) Bz) and geomagnetic indices (Sym‐H (symmetric horizontal) and auroral electrojet (AE)) during these storms. We analyzed the time lag between the MCEF and AE, Sym‐H, and IMF Bz using a cross‐correlation analysis. The study shows that CMEs arriving in the magnetosphere at a speed of 800–960 km/s induce a change in MCEF of 0.95–1.29 mV/m in the initial phase, and those transiting at a speed of 520–651 km/s induce a change in MCEF of 0.78–0.91 mV/m. During storms associated with CMEs arriving at a speed of 520–651 km/s, a change in IMF Bz of 1 nT is associated with a change in MCEF of about 0.05 mV/m. During those associated with CMEs transiting at a speed of 800–960 km/s, each 1 nT change in IMF Bz corresponds to a change in MCEF of about 0.07 mV/m. Variations in the MCEF follow those in the AE index in 88% of the storms studied, with a time lag ranging from 9 to 79 min. They precede those of the ring current index (Sym‐H) in 50% of the cases analyzed, with a time lag varying from 49 to 742 min. These results provide us with some information on the complete evolution of geomagnetic storms, with a view to better prediction.
Extreme flooding is becoming a more serious hazard to the world’s infrastructure, especially in high-risk locations, and is linked to global warming and human activity. This research employs an analytical hierarchy process (AHP) model and geographic information system (GIS) analysis to delineate flood risk zones. An eight-factor multiparametric method to flood risk susceptibility mapping includes precipitation, distance to river, the slope, elevation, land use/cover, topographic wetness index, type of soil, and curvature. An urban flood risk index (UFRI) is established based on vulnerability mapping, revealing that approximately 33% of Haripur District, Khyber Pakhtunkhwa, Pakistan, is prone to floods. Additionally, land use cover analysis indicates that 23% of the crop area in Haripur District is at risk from flood disasters. Recognizing the potential for costly damage to infrastructure, flood hazard mapping serves as a valuable tool to prioritize risk areas for urban and agricultural development. The outcomes of this study are anticipated to significantly contribute to predisaster flood control management in the studied area.
The tectonic complexity in Indonesia has made it one of the most interesting targets for studies on seismic tomography. The Indian oceanic plate sunk beneath the Eurasian continental plate, forming the subduction zone in Southern Indonesia. This activity led to the formation of volcanoes along the Sunda Arc, including East Java, the research area covered in this study. This research is mainly aimed at identifying the influence of the volcanic activities by tomography analysis. The data of the earthquakes was recorded by 22 seismic stations of the Indonesia Tsunami Early Warning System (InaTEWS) seismic network in the period of 2009–2017. The tomographic image was analysed by exploring the anomalies of primary (P)‐ and secondary (S)‐wave velocities and Vp/Vs ratio. The result shows the presence of a low‐velocity zone with a high Vp/Vs ratio found around the volcanic area, which is correlated with the partial melting zone or magma chamber. The low‐velocity zone was observed at the depth range of 27–155 km, which was also correlated with the subducted slab beneath Java Island. This leads to an assumption that there is an interlinked volcanic system which extends from west to east of Java.
Groundwater resource in the “Larena Plain” at the western margins of the Southern Main Ethiopian Rift (SMER) was investigated using integrated geophysical techniques—electrical resistivity and magnetic methods. The objective was to assess aquifer depth, extent, and geological controls in the study area. Vertical electrical sounding (VES) was employed to examine and map aquifer depth and lateral extension, while geological structures and lithological contacts influencing groundwater flow and accumulation were identified using magnetic surveys. Two-stage aquifers were identified: a deeper fractured ignimbrite and a volcanoclastic sediment aquifer covered by shallow weathered ignimbrite. The depths and distributions of these aquifers were mapped, with geological structures generally aligned in the NNE–SSW orientation. Understanding these geological structures and aquifer systems is crucial for effective groundwater management in the “Larena Plain,” providing valuable insights for regional hydrogeological studies.
