The Ionian margin of southern Italy is one of the most complex geodynamic regions in the central Mediterranean, where ongoing convergence between the African and Eurasian plates results in intense seismic activity and highly heterogeneous crustal structures. To improve seismic monitoring in this region, within the framework of the ERC Advanced Grant FOCUS (2018‑2025), a temporary onshore seismic network (FXLand) was deployed along the Ionian coasts of Sicily and Calabria from December 2021 to June 2023, complementing a marine array of ocean‑bottom seismometers operating during the same period. In this study we describe the deployment and performance of the 13 temporary broadband stations of FXLand. The network was integrated in real time into the Italian national seismic surveillance system, enhancing data availability and coastal network geometry. During the deployment, FXLand recorded, more than 1,500 local earthquakes and more than 200 teleseismic events with magnitude M ≥ 6. We also present results from the analysis of three seismic sequences that occurred during the network operational period. The application of a Template Matching technique to the combined permanent station and FXLand network dataset, we significantly increased the number of detected low‑magnitude earthquakes in onshore area, improving catalog completeness compared to real‑time surveillance and Italian Seismic Bulletin. On the other hand, the offshore sequence highlights the main limitations of land‑based networks in detecting and accurately locating submarine seismicity. The integration of marine observations from the ocean‑bottom seismometer network in the Ionian Sea is expected to provide substantial improvements in the detection and location accuracy of offshore earthquakes, contributing to a more complete characterization of seismic activity along the Ionian margin.

Remanent magnetisation is a critical challenge in magnetic interpretation, often leading to mispositioned anomalies and unreliable inversion results when neglected. This study applies and validates a practical, sequential two‑step workflow that integrates existing techniques to improve magnetic modelling in scenarios where remanent components significantly influence the anomaly geometry. In the first stage, the total magnetisation direction is estimated using the Equivalent Layer technique, which reconstructs the effective magnetisation vector from the observed anomaly without decomposing it into induced and remanent components. The magnetisation direction estimated via the equivalent layer technique was used to perform the reduction to the pole (RTP), and the inversion was subsequently carried out assuming a vertical inducing field (D = 0°, I = 90°). The methodology was tested on synthetic models with varying remanent contributions to evaluate its performance in controlled conditions. Results demonstrate that incorrect directional assumptions lead to distorted source geometries and underestimated susceptibilities, whereas using the Equivalent Layer estimated direction significantly improves inversion accuracy. The approach was also applied to a real airborne magnetic dataset from Espírito Santo State, Brazil, where it successfully recovered a westward‑dipping magnetic body with coherent susceptibility structure. Residual analysis confirmed strong agreement between predicted and observed fields, reinforcing the method’s robustness. While the current implementation assumes a constant magnetisation direction within the target volume, making it less suitable for geologically complex bodies, it offers a stable and interpretable solution for cases where remanence is spatially coherent. This study provides a practical, reproducible workflow for the integrated application of EL‑based direction estimation, RTP, and VOXI susceptibility inversion to remanence‑affected datasets. This workflow is compatible with standard modelling platforms and provides a practical reference for remanence‑affected magnetic interpretation.

The study aims to determine the depth of subsurface sedimentary layers using a Fourier‑based 3‑D stripping inversion method and assess its accuracy. The seismic‑based depth maps of the top Dabaa, Kharita, and El Alamein Formations in the Burg El‑Arab Area were utilized to evaluate the inversion process’s accuracy. The calculated gravity effects of the top Dabaa, Kharita, and El Alamein Formations range were analytically estimated from thickness and density contrast and assigned to the surface observation level (Bouguer stations) before sequential stripping. The apparent density was calculated in addition to the upper and lower depth bounds of each sedimentary layer, which were used as constraints during 3‑D Fourier‑domain inversion procedure. The inversion results showed satisfactory fit statistics compared to seismic‑based depth data. The analysis of the inversion’s performance for the three inverted sedimentary layers showed that the percentage error between the inverted‑based depth and the seismic‑based depth was ranging from ±0.004 to 21.67%. The seismic and inverted‑based depths of the top Dabaa, Kharita, and El Alamein Formations were found to have correlation coefficient values of 0.88, 0.82, and 0.75, respectively. A 2‑D model was created for four horizons, including the basement layer. The 2‑D modeling indicated that the study area is affected by a number of normal faults that cross most of the layers and dip into the NE and SW directions, with dipping angles ranging from 70° to 80° and 75° to 85°, respectively. The 3‑D inversion results demonstrated that gravity measurements can accurately determine the depth of the sedimentary layer when stripping is performed at the Bouguer‑station level and the inversion is constrained by density and seismic information, with a tolerance of up to 21.67% and decrease until it matches the true depth in some locations.

Distributed Acoustic Sensing (DAS) has emerged as an innovative technology in seismology, sensing seismic waves along fiber optic cables and, thus, increasing ten‑folds the spatial density of seismic measurements. However DAS potential in seismic monitoring is still under investigation. In this study, we assess the differences in seismic event detection and localization when using DAS, conventional seismometers, and combination of both, by analyzing a dataset acquired during a field experiment in Megolo di Mezzo (Northern Italy). A ~1 km buried fiber optic cable was deployed with an almost L‑shape configuration. Seismic data were continuously recorded from November 2023 to February 2024 and compared with simultaneous observations from the local seismic network (DIVEnet). Several local earthquakes were detected, including microseismic events not listed in the official catalog. P‑wave arrival times were extracted from DAS recordings using different picking algorithms and compared to manual picks from seismometers. Event localization was performed through a Bayesian Monte Carlo approach applied separately to DAS and seismometer data, and jointly. Results demonstrate that DAS shows considerable potential in earthquake detection, particularly for low‑magnitude events and those occurring close to the fiber optic cable, as potentially expected during anthropic activities underground. The joint inversion of DAS and seismometer datasets reduced localization uncertainties and produced solutions consistent with the official INGV catalog. However, differences of up to ~2 km between DAS – and seismometer – based epicenters highlight the limitations of simplified velocity models and the impact of network geometry. These findings confirm the complementarity of DAS and traditional networks and underline the potential of hybrid monitoring strategies for advancing earthquake detection and characterization in complex geological environments.

This research aims to identify the most appropriate predictor for the Vertical‑to‑Horizontal (VH) ratio of the Peak Ground Velocity (PGV) from the five existing models in the literature useful for regional or site‑specific probabilistic seismic hazard assessment, and practical applications in the Bay of Algiers. Firstly, dataset of 285 observed VH ratios of PGV was compiled from nine seismic stations within the study area, installed on different flat and irregular surfaces. This dataset was derived from earthquakes with moment magnitude (Mw) ranging from 3.3 to 5.3. Next, the dataset was categorized into two groups based on the soil type at the station locations: rock (S1) (Vs30 above 800 m/s) and stiff (S2) (Vs30 360‑800 m/s) soils. After that, a preliminary linear regression analysis was performed for each group of observed VH ratios of PGV as a function of the Joyner‑Boore distance (RJB) of near field and compared with three selected candidature predictors: Akkar et al. (2014), Bozorgnia and Campbell (2016), and Ramadan et al. (2021) (RA2021). For an extensive evaluation, the Euclidean Distance‑based ranking method (EDR) was applied on the three mentioned candidature predictors. For rocky soil, the results indicate that all models closely align with the linear regression fit, around a VH ratio of PGV of 0.6. However, RA2021 appears to provide a reasonable fit, with a VH ratio of PGV of 0.4 for stiff soil, despite the significant site‑effects at the respective stations. The EDR showed that RA2021 gives the lowest sigma with the observed ratios for S1 and S2 soil classes. For the far field, estimates of the VH ratio of PGV are provided for three strong earthquake magnitudes (6.5, 7.0, and 7.5) and different soil classes, using the existing models.

The safety of tunnels and roads is crucial for traffic safety. Due to the presence of adverse geological features, which can cause serious problems in tunnels and on roads, there is an urgent need for comprehensive geophysical investigations to determine their distribution. This will provide additional technical information to help ensure the safety of engineering projects. This study uses the tunnels and roads in Jiulong County, Sichuan Province, as an example. Integrated geophysical methods were employed to arrange ERT sections at tunnel entrances and exits, as well as on geophysical slopes. The primary focus was on the thickness of the overlying layers and the geological conditions of the rock and soil within a certain depth range above the tunnel design line. For the longitudinal cross-section of the main tunnel, Audio Magnetotelluric (AMT) were primarily used to investigate fault zones, karst formations, aquifers and rock mass grades. Combining electromagnetic data denoising and inversion using a U-Net neural network with ERT inversion clearly revealed the underground geological conditions of the tunnel. The tunnel alignment is characterised by a mixture of stable quartz-rich rock masses and metamorphic rock masses. Overall, the deep rock mass of the tunnel axis is stable, with fractures in some transverse sections. The intersection is relatively stable, interspersed with weathered and fractured zones. These findings provide valuable insights into advancing geophysical techniques for investigating tunnel sites under complex geological conditions.

This study tries to advance the understanding of the Salse di Regnano mud volcanoes within the framework of an INGV project by integrating geomorphological, geochemical, historical, and remote-sensing data. Detailed analyses of morphology and geochemistry revealed distinctive geometric features and enabled reconstruction of the historical configuration of the area. The research was then extended by integrating drone-based geomagnetic surveys with digitized historical maps transformed into normalized 3D models. High-resolution topography derived from Structure-from-Motion (SfM) photogrammetry, complemented by satellite imagery and archival sources, allowed a comprehensive analysis of surface and subsurface patterns. The resulting geomagnetic anomaly maps reveal a “tongue” of low values descending from the northern upper slope into the main mud area, which broadly aligns with relative morphological features. Additional anomalies highlight structures of potential geophysical interest for further investigation. Historical reconstruction indicates a markedly different summit in the early 20th century, dominated by a prominent emission cone that reshaped the area following a paroxysmal event in the 1930s. Building upon previous findings, these new observations continue to provide guidance for subsequent investigations, which will include a targeted geophysical campaign combining passive seismic and electrical resistivity surveys to probe the subsurface. This multidisciplinary approach demonstrates the potential of integrating modern geophysical measurements with historical and morphological information, providing an evolving framework that adapts as new data become available and enhancing our understanding of the evolution of mud volcano systems over time.

In the present paper we have reconstructed the geologic substrate in the area of Rome comprised between the Capitoline Hill and the Colosseum. The analysis of the stratigraphic logs of a large number of boreholes allowed us to highlight the occurrence of a buried fluvial channel of the Paleo- Tiber River, the geometry of which mimics, almost exactly, the fluvial bend hosting the present-day Tiber Island. Several 40Ar/39Ar dates allowed at discriminating two aggradational successions filling this paleo-channel, deposited during two consecutive glacio-eustatic cycles corresponding to Glacial Termination VIII (621 ka) and VII (534 ka). The buried paleo-channel corresponds with a partially obliterated NW-SE morpho-structural lineament affecting the present morphology, parallel to another, more marked lineament, hosting a tributary valley of the Tiber River, the Murcia Valley, 1 km to the southwest. Such lineaments match with the direction of the main Pleistocene extensional faults on the Tyrrhenian Sea margin of central Italy, which are re-activated under the present-day tectonic regime, exerting a close structural control on the drainage network of the Tiber River catchment in the area of Rome. The activity of one of these faults, running along the Murcia Valley, has been recognized to be responsible for the diversion of the Tiber course and the birth of the Tiber Island during the 6th century BCE. We conclude that a long-lasting structural control existed on this portion of the Tiber valley, which caused the repeated diversion of the river channel, around 650 ka and 550 ka, and ultimately in the 6th century BCE, creating the conditions for the origin of a fluvial island in correspondence with the fault-controlled river bend.

This study employs an integrated geophysical approach, combining Electrical Resistivity Tomography (ERT) with Dipole-Dipole, Pole-Dipole, and Pole-Pole arrays and Vertical Electrical Sounding (VES) with a Schlumberger array, to delineate groundwater resources in the municipality of Sucupira do Norte, Maranhão, Brazil, a region with water scarcity. The survey successfully identified three aquifer units: a shallow unconfined aquifer (<35 m depth; 10 to 100 Ω∙m) considered unsuitable for use due to the risk of contamination, and two deeper confined aquifers. Aquifer B was identified at depths of 60 to 90 m, with resistivity values of 500 to 600 Ω∙m, while the main target, Aquifer C, was found at depths of 140 to 190 m, with lower resistivity values of 50 to 100 Ω∙m, indicative of water-saturated sandstones within the Pedra de Fogo Formation. Based on these results, two specific drilling locations were defined, with recommended depths of 160 m and 270 m to ensure sustainable production. The results demonstrate the effectiveness of integrating Electrical Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES) to reduce uncertainty in exploration and provide a robust strategy for the sustainable management of groundwater in drought-prone regions.

Santorini Island is of volcanic origin and has historically faced repeated volcanic and seismic activity. In early 2025, increased volcanism and intensified earthquake activity, similar to 2011-2012, caused residents’ concern. This study aims to characterize ground deformation on Santorini Island during its volcanic unrest in 2025 using InSAR observations. For this purpose, 74 synthetic aperture radar (SAR) images of Sentinel-1A satellites in descending and ascending orbits were acquired from early January 2024 to late March 2025. Line-Of-Sight (LOS) velocity values of the descending and ascending orbits were decomposed to determine the east-west and vertical displacement velocities. According to the results obtained, uplifts up to +60 mm/year velocity values were detected in the central parts of the island called Caldera, and subsidence up to –30 mm/year velocity values were detected in the outer regions. In addition, eastward horizontal movements reaching velocities of +60 mm/year and westward horizontal movements reaching velocities of –50 mm/year were also detected throughout the island. In the second stage of the study, a total of 4 points were selected on the islands of Thira, Thirasia, Nea Kameni, and Palea Kameni, considering the Kameni and Kolumbo fault zones. For these points on the island of Santorini, the displacements occurring over 15 months were analysed by time series analysis, and the temporal behaviour of the deformation (increasing/decreasing trend) was monitored. The analysed data indicate that the ongoing horizontal and vertical movements on the island could be caused by volcanic rather than seismic effects, which is consistent with previous studies. This situation shows that volcanic risk assessments in the region should be monitored for the upcoming processes.