Francesco Emanuele Maesano

Predicting the geoneutrino signal at underground detectors requires a local crustal reference whose precision matches the experimental uncertainty. The current Borexino reference is 15 years old and deterministic. We replace it with GUESS, a probabilistic 3‐D model of the Gran Sasso region, built by Bayesian inversion of multi‐source geophysical data: ground and satellite gravity, deep exploration wells, seismic profiles, receiver‐function Moho constraints, and high‐resolution topography are fused into a posterior distribution of density and lithological label per voxel. The model partitions the volume into six lithologically distinct units, each with quantified uncertainty on volume, mass and average density, and is validated against three independent in situ density benchmarks. The structural uncertainty on the predicted geoneutrino signal of the major units is constrained to 1%–3%, an order of magnitude below the uncertainty on uranium and thorium abundances. The dominant source of error in the absolute crustal geoneutrino prediction therefore shifts from crustal geometry to elemental composition, defining the next priority for the Borexino determination of the radiogenic heat budget.

Controlled Source Seismic (CSS) data are key to understanding the structure and composition of the lithosphere at different scales. They are highly valuable both in their own right and as input to multidisciplinary studies and Earth system modelling. The challenge for scientists is to find existing data, assess their relevance for a particular purpose, and eventually get access and permission to reuse selected data sets. The European research infrastructure for solid Earth sciences, EPOS (European Plate Observing System) was designed to solve such problems. It is a multidisciplinary, distributed research infrastructure that facilitates the integrated use of data, data products, and facilities from the solid Earth science community. FAIR principles are put into practice, enabling access to data and products from hundreds of scientific data services across Europe. A community building effort for Controlled Source Seismic data was started at the EGU24 and SEISMIX2024 conferences, with the aim of developing a metadata model for data set discovery, as no existing standards or common practices for describing CSS data sets could be identified. This objective was achieved by early 2026 and the results are presented in this paper, together with a data service as an interface to the EPOS Platform. The metadata model is sufficiently detailed to allow a scientist to decide whether a discovered data set is fit for the intended reuse purpose or not. On the other hand, obligatory attributes are limited to avoid incompatibility with the diverse metadata models of potential data providers. The EPOS CSS metadata catalogue will meet FAIR and Open Data principles. The data sets registered in the metadata catalogue should ideally also be FAIR and Open. However, enforcing such a policy would exclude a large part of the existing seismic data. Therefore, the metadata model was designed to also describe closed data by providing suitable information on the legal constraints. In this way, the CSS metadata catalogue will be most useful to the scientists by providing the largest coverage while also advertising FAIR data and Open Science to the data providers.

Understanding the recent tectonic activity of buried faults represents a challenge for scientists. In the offshore portion of the Northern and Central Apennines foredeep basin in the Central Adriatic Sea, Italy, high sedimentation rates, exceeding tectonic uplift since the Pliocene, and the offshore location are hampering the detection of recent or ongoing tectonic activity. The thick Plio‐Pleistocene deposits cover the outermost sectors of the Northern and Central Apennines fold‐and‐thrust belt, particularly in its offshore portion (the Adriatic Sea). The historical (pre‐instrumental and instrumental) seismicity in the region is moderate, with seismic sequences characterized by mainshocks with magnitudes ranging from 4.5 to 5.5 over the past century (the last earthquake with M > 4 was registered on 9 November 2022, M _w 5.5 near the coast between Pesaro and Ancona). The purpose of this work is to quantify the Plio‐Pleistocene tectonic activity by calculating the buried thrust slip‐rates and assessing their potential activity. Two regional seismic reflection profiles were interpreted, depth‐converted, and restored to calculate the buried thrusts' tectonic activity. Based on five stratigraphic horizons with well‐constrained age determinations (Zanclean to Middle Pleistocene), we determined the slip necessary to recover the observed tectonic deformation. The slip rates were then calculated using probability density functions that account for uncertainties arising from both horizon ages and the restoration process. Our results show a progressive reduction of tectonic activity over time, with a main slip‐rate slowdown around 1.5 Ma. Even during a substantial decrease in regional tectonic activity, local, mainly qualitative observations of specific structures indicate ongoing activity, as demonstrated by recent seismic sequences.

The junction between the central and southern Apennines represents a high-seismic-hazard region in the Mediterranean. Its seismotectonic setting is characterized by a complex, poorly understood interplay between SW-NE regional extension along the range axis and E-W mid-to-lower crustal shear zones in the Adria plate to the east. Although the range axis hosted several M6-7 historical earthquakes, their causative faults remain mostly debated. Monitoring by the Italian National Seismic Network (Rete Sismica Nazionale, RSN), with a station spacing of 10-30 km and a detection threshold of about ML1.2 in the region, has proved insufficient to pinpoint and fully characterize source faults for recent low-to-moderate magnitude (M < 4) sequences.To address these limitations, we conducted the first comprehensive study of background seismicity as part of the MOSAICMO project, an inter-disciplinary initiative investigating tectonic evolution and seismogenesis of this region. This study integrates a 2-year passive seismic experiment (2023-2025) with a re-analysis of the 2016-2022 RSN seismicity. Our objectives were to improve knowledge of the active faults and relationship between seismogenesis and physical properties of the crustal rocks. The seismic experiment integrated 13 temporary stations with 20 permanent stations of the RSN over an area of 60x60 km2, reducing station spacing to 4-12 km. Initial analysis of the first nine months of the new dataset using a standard STA/LTA algorithm identified 470 events (0.2 < ML < 2.8), representing a 220% increase over the RSN catalog. For these earthquakes, P-and S-phases were manually picked. For the 2016-2022 seismicity, we revised and augmented the phase picks for 1,400 selected events and applied cross-correlation template matching to a prolonged swarm-like sequence (2016-2017; Mw 4.3) to produce a high-resolution catalog.We utilized these phase picks to construct catalogs, through: i) absolute locations using the probabilistic location software NonLinLoc and a new optimized 1D velocity model, based on a non-linear approach ii) high-precision relative locations using the double-difference technique HypoDD; iii) absolute 3D re-locations alongside with Vp and Vp/Vs crustal models derived from Local Earthquake Tomography on a 3 × 3 × 2 km grid.Our results show that seismicity deepens eastward, from 3–12 km beneath the inner range to 15–22 km under the outer range. While the upper crust exhibits mixed extensional and strike-slip focal mechanisms, deeper eastern events are almost exclusively strike-slip. Most seismicity occurs in small, short-lived clusters. Along the inner range, seismicity concentrates at 5-10 km depth within high-Vp (6.0-6.7 km/s), low-Vp/Vs (1.70-1.85) zones. Here, high-precision relocations reveal NW-striking, NE-dipping alignments consistent with known Quaternary normal faults. Integrating these results with a subsurface geological model based on seismic commercial profiles and exploration wells, and a 2D magnetotelluric tomography, we find that: (i) axial seismicity is mainly hosted within the high-velocity, high-resistivity Mesozoic carbonates of the Apulia Platform, (ii) the 2016–2017 swarm-like seismicity also clusters within the Apulian Platform but correlates with a low-resistivity anomaly, suggesting a fluid-driven seismogenic mechanism.

Geoneutrinos, electron antineutrinos produced by the radioactive decay of Uranium (U) and Thorium (Th), offer a unique real-time window into the Earth’s interior composition and radiogenic heat budget. These particles are detected by large-volume underground scintillators where cosmic ray backgrounds are minimized. However, the lack of directional sensitivity in current liquid scintillator detectors, such as Borexino (Gran Sasso massif, Italy), results in a signal degeneracy that necessitates highly accurate models of the local lithosphere to isolate the mantle contribution.In the framework of the GUESS project (GeoneUtrinos: mESSengers of the Earth's interior), we present a high-resolution 3D geophysical model of Central Italy specifically tailored for geoneutrino signal prediction. Addressing the limitations of previous models, this work adopts a joint multi-disciplinary approach.The "GUESS model" is computed inverting ground gravity data integrating heterogeneous datasets as prior information in a Bayesian framework. The geological and geophysical prior datasets include: 1D stratigraphic data from deep exploration wells; 2D interpreted seismic profiles and geological cross-sections; 3D passive seismic data (receiver functions) to constrain the Moho discontinuity. This probabilistic framework discretizes the crust into six lithological units, from Quaternary volcanics to the Lower Crust, and explores high-dimensional solution spaces in terms of both geometry and density distribution via simulated annealing. This methodology not only optimizes mass and volume estimates according to both gravity and geophysical data but also provides a quantification of estimation uncertainties by Monte Carlo samples. This workflow demonstrates how the integration of potential field data with seismic and geological constraints provides a robust, geodynamically realistic architecture, advancing both neutrino geoscience and our understanding of complex lithospheric structures.This study was supported by the project GUESS (GeoneUtrinos: mESSengers of the Earth's interior) funded by European Union – NextGenerationEU, Missione 4, Componente 1(CUP: F53D23001280006).

The westernmost Mediterranean basins formed in a supra-subduction system during the Miocene. We have found that since the late Miocene, the previously extending region has been deformed by contractional and strike slip fault systems due to the Iberia – Africa tectonic plates convergence, producing the reorganization of the main tectonic structures. The westernmost Mediterranean realm is seismically active because it hosts the plate boundary between the European and African tectonic plates. This plate boundary has been traditionally considered a wide deformation zone, in which plate convergence is absorbed by minor to moderate-size tectonic structures, each absorbing a comparatively small part of the deformation. However, the understanding of the crustal configuration and the evolution of this basin was limited due to the limited penetration and resolution of the images of the subsurface.We collected and processed >3.000 km of a modern seismic dataset to characterized for the first time 1) the deep structure and the crustal domains of the Alboran Basin, 2) the sedimentary infill and as a consequence, the basin evolution, and 3) the main active faults of the basin. Based on these results, we were able to identify the main fault systems and quantify the total slip accommodated by those prominent tectonic structures of the area, late Miocene - early Pliocene in age. Our results show that the estimated total slip accommodated by the main fault systems is similar (with error bounds) to the estimated plate convergence value since the Messinian time (~24 km). Thus, slip on those faults may have accommodated most of the Iberian – African plate convergence during the Plio-Quaternary, revealing that the contractive reorganization of the Alboran basin is focused on a few first-order structures that act as lithospheric boundaries, rather than widespread and diffuse along the entire basin. These results have implications not only for kinematic and geodynamic models, but also for seismic and tsunami hazard assessments. We performed a first appraisal of the seismogenic and tsunamigenic potential of the main fault systems offshore. Our simulations show that the seismogenic and tsunamigenic potential of the offshore structures of the Alboran Basin may be underestimated, and a further characterization of their associated hazard is needed.

The Matese-Sannio region in Southern Italy represents a crucial sector to analyse the processes that characterized the formation of Apennines and its current structural setting. This area is also of great interest from a seismotectonic point of view, hosting the epicentres of multiple historic destructive earthquakes.Our study presents part of the results of a multidisciplinary project (MOSAICMO) that integrates multiscale approaches to produce: a regional-scale model of this part of the orogen, a detailed reconstruction of the shallow subsurface of the Quaternary Bojano intramountain basin located in the central part of the study area, and detailed seismological and geophysical analyses.In this work, we present the 3D subsurface reconstruction of the Matese-Sannio region, exploring the orogen structure to a depth of ca. 10 km by using a dense network of seismic reflection profiles tied with well-logs drilled for hydrocarbon exploration.We tested the reliability of our geological reconstruction by performing numerical kinematic forward models that provide independent geometrical and temporal constraints to our conceptual model. We then compared our results with previous paleogeographic reconstructions of this sector of the Apennines to shed light on the complex interaction among different paleogeographic domains insisting in a relatively limited region.Our results provide an updated picture of the present-day structure of the transition between Central and Southern Apennines and represent a reference framework for more detailed applications within the MOSAICMO project.

In the Central Apennines (Italy), the project RETRACE-3D provided a reliable 3D model of the crust in the area affected by the 2016-17 Amatrice-Visso-Norcia seismic sequence, highlighting that the coseismic rupture at the surface can involve old inherited normal faults while the seismogenic sources lay at depth, possibly reactivating and inverting previous thrust faults, as in the case of the Mw 6.5 Norcia earthquake (30 october 2016). Here we present a 2D gravity model across the Central Apennines, spanning from the Tyrrhenian coast to the Adriatic Sea, aimed at completing and verifying the crustal geometries resulting from the 3D model itself. The cross-section was built integrating different types of data, such as surface geology, hydrocarbon wells, seismic lines, and results from receiver function analysis. It was then checked against gravity anomalies and the velocity distribution from Local Earthquake Tomography (LET), adding further details, and, finally, against seismicity recorded during the 2016-2017 sequence. The results substantiate the reliability of the geometries proposed in the RETRACE 3D model, as they fit well, except for some local misfits, with the other independent data, such as the Bouguer anomalies and the velocity distribution from LET. Furthermore, the integration of different types of data allowed us to describe in detail the structural setting of the Apennine chain also in the surroundings of the RETRACE study area, where the cross-section length exceeds the 3D model, and to add some new elements at seismogenic depths, that exceed those typical of hydrocarbon exploration. In particular, we were able to investigate the nature of the basement top and its relationship with seismotectonics.

Earthquakes of engineering significance (magnitude 5 and above) are generated by pre-existing, relatively mature geological faults. These faults generally span a length from a few to several tens or hundreds of kilometers and can break the entire Earth’s crust. Defining the three-dimensional configuration of such seismogenic faults is crucial for developing applications for earthquake hazard analyses at different spatial scales and, in turn, contributing robust information to promoting earthquake risk mitigation strategies.The reconstruction of geological fault surfaces is a typical multidisciplinary study involving a large variety of data types and processing methods that, inevitably, imply various degrees of geometric simplifications depending on the available data. Among them, the most powerful, although expensive, approaches are the techniques developed for hydrocarbon exploration, namely seismic reflection (2D-3D) data combined with logs of drilled wells, which can illuminate the Earth’s subsurface at several kilometers depth. The mining and oil and gas industries have historically collected a large amount of this data, which remained classified depending on the regulations of the country from which they obtained the license for exploration. As time passes, and with the waning of fossil fuel exploitation, the exploration licenses expire or are not renovated, and more of such data becomes available to amalgamate with data collected by research institutions or public/private ventures using public funding. Despite the vast literature on and applications of hydrocarbon exploration data, no standard procedure exists for documenting the use of such data in characterizing seismogenic faults. In this respect, scientists face challenges posed by the intersection of industry data with public research outputs, with important societal implications and barriers to ensuring FAIRness. To this end, we devised a workflow detailing the best practices to follow in the various steps geologists undertake in using hydrocarbon exploration data, starting from the source of the raw/processed data (public vs confidential) and ending with the final geological fault model. The workflow output is then ready to be integrated with the information and data from other scientific disciplines (e.g., seismology, paleoseismology, tectonic geomorphology, geodesy, geomechanical modeling, earthquake statistics) to obtain the most reliable seismogenic fault model. As proof of concept, we will present a simplified version of a software tool that guides the user in incorporating the workflow's various elements into a structured database of seismogenic faults.

Understanding the recent tectonic activity and seismotectonics of inaccessible buried faults requires the development of feasible and robust approaches. The foredeep deposits of the northern and central Apennines (an offshore area in the central Adriatic Sea, Italy) blanket the active buried frontal thrusts of the Apennines and the Dinarides orogens. Detecting recent-to-ongoing tectonic activity of these thrusts is particularly challenging because sedimentation rates easily exceed the very slow tectonic rates.In this work, we combine seismic reflection profile interpretation, sediment decompaction, kinematic restoration and balancing to quantitatively analyse the Plio-Pleistocene tectonic activity of the Apennines and Dinarides buried thrusts in the central Adriatic Sea and calculate the slip rates of the major faults. The northern and central Apennines foredeep is filled by a thick Messinian to Quaternary sedimentary wedge, unconformably resting on a Meso- Cenozoic carbonatic and siliciclastic passive margin succession, which is in turn involved in the east-northeast propagation of the fold-and-thrust belt from onshore to offshore (Adriatic Sea). As suggested by previous studies, the region is in a substantial tectonic activity decrease, but local and qualitative observations on specific structures show evidence of recent tectonic activity. The frontal thrusts of both the Apennines and the Dinarides are active, as also demonstrated by the moderate seismic activity historically (few past centuries) recorded in the region and by the recent earthquakes, followed by rather rich aftershock sequences that occurred in this region and nearby (e.g. the Porto San Giorgio earthquake Ml 5.0 in 1987; the Jabuka earthquake Mw 5.5 in 2003, the Pesaro earthquake Ml 5.7 in 2022). We interpreted, depth converted, and restored two northeast-trending regional seismic reflection profiles, thus roughly orthogonal to the main strike of the buried thrusts. We then used the inverse trishear approach to determine the slip necessary to recover the residual tectonic deformation (after decompaction) of four stratigraphic horizons with well-constrained age determinations (Zanclean to Middle Pleistocene). We then calculated and reported the slip rates using probability density functions, considering the uncertainties associated with both horizon ages and the restoration process. All together, our results show a progressive reduction of slip rates over time, with a main slowdown around 1.5 Ma. Reporting slip rates with probabilistic distributions is useful for incorporating epistemic uncertainty on the total seismic moment release in earthquake hazard analyses.