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.

The Apennine Tyrrhenian margin records the evolutionary steps of the back-arc basin developed at the rear of a E-ward migrating fold-and-thrust belt. As well-documented in literature, the counterclockwise rotation of the Apennines is related to the southward increase of the roll back-related subduction of the Adria slab. This led first to the progressive incorporation of thrust sheets within the Apennine prism in the upper plate and later to its subsequent back-arc extension that is contemporaneous with the continuate inarching of the Apennine front towards the Adriatic and Ionian seas. Uncertainties arise on the structural style and timing in the internal Apennines between the orogenic and post-orogenic stages, that are respectively represented by thrust-sheet implacement, and crustal thinning. We hereby propose a combined 2D seismic and field data review that allows identifying the geodynamic processes preceding the crustal stretching of the Apennine Tyrrhenian margin with new insights from on- and off-shore seismic lines. In particular, the construction of a new geotraverse across the margin, which is stretched over 100 km between the internal Central Apennines belts and the Pontian escarpment, allows to roughly estimate: i) the Late Miocene - Earliest Pliocene shortening with its change of the basal decollement depth through time; in particular, subsurface data highlighted stacked thrust sheets that were involved in an initial in-sequence propagation with top-to-the-ENE, synchronous to late Tortonian foredeep to wedge-top sedimentation. We also distinguish late backthrusts related to the formation of triangle zones that are more deeply rooted moving to the western chain interior. ii) The amount of crustal stretching and subsidence; Back arc-related orogenic collapse is preceded by initial orogen uplift and erosion in the internal sectors. iii) The onset of at least two magmatic cycles; in this frame, the lateral slab tearing and retreat is tracked by E-rejuvenated volcanic activity in the upper plate along the Volsci Volcanic Field and the Palmarola-Vesuvius lineaments. Those volcano-tectonic trends are favoured by a series of transtensive structures that progressively reflect the arc expansion in the rear. In this frame, the NE-dipping crustal detachment(s) may have played into crustal thinning during the Pliocene, driving and occasionally hampering magma emplacement, while high-angle faults have locally driven monogenetic eruptions. Finally, we report on field and seismic evidence of neo-tectonics, supporting ongoing extension occurring on the margin.

The polyphase structural evolution of a sector of the internal Central Apennines, where the significance of pelagic deposits atop neritic carbonate platform and active margin sediments has been long debated, is here documented. The results of a new geological survey in the Volsci Range, supported by new stratigraphic constraints from the syn-orogenic deposits, are integrated with the analysis of 2D seismic reflection lines and available wells in the adjacent Latin Valley. Late Cretaceous syn-sedimentary faults are documented and interpreted as steps linking a carbonate platform to the adjacent pelagic basin, located to the west. During Tortonian time, the pelagic deposits were squeezed off and juxtaposed as mélange units on top of the carbonate platform. Subsurface data highlighted stacked thrust sheets that were first involved into an initial in-sequence propagation with top-to-the-ENE, synchronous to late Tortonian foredeep to wedge-top sedimentation. We distinguish up to four groups of thrust faults that occurred during in-sequence shortening (thrusts 1–3; about 55–60 km) and backthrusting (thrust 4). During Pliocene to recent times, the area has been uplifted and subsequently extended by normal faults cross-cutting the accretionary wedge. Beside regional interest, our findings bear implications on the kinematic evolution of an orogenic wedge affected by far-traveled units.

In this paper, we propose innovative solutions for reusing an inactive offshore gas platform and its associated infrastructures as a scientific research hub, where an integrated energy system and innovative environmental monitoring methods are envisaged.To this end, the Azalea A platform, located in the northern Adriatic Sea, is considered a good pilot site.This study analyzes the engineering solutions on Azalea A for the combined production of solar and wind energy coupled with hydrogen production from seawater electrolysis.It analyzes the potential for storage and transport on land of the produced hydrogen using the sealines connected to the platform.However, this study does not deal with the current structural conditions of the platform (corrosion, stability etc.), which should be evaluated before these solutions are put into practice.The main outcomes of this work consist in a feasibility study for the reuse of existing infrastructures as a self-sufficient research hub using green energy systems, which include considerations about the measures needed to ensure the protection of the marine environment.Data show a positive feedback about the technical feasibility of the proposal in safety conditions.Furthermore, encouraging outcomes derive also by the economic evaluation that estimates sustainable costs comparing to those implicated with the decommissioning of the infrastructures in the order of tens millions euro.In addition, the proposed reuse seems to be a good opportunity to promote both energy transition toward renewable energy systems and environmental protection, avoiding decommissioning impacts and promoting an innovative monitoring program for the Adriatic Sea.

In west-directed subduction zones, as the compression moves towards the foreland, the accretionary prism progressively expands to follow the hinge migration towards the east. Although late Miocene foreland propagation implies the shift of the thrust front, in the central Apennines, the effects of the Messinian compression can be observed on a much broader area, implying out-of-sequence thrusting in the rear. In order to understand the Messinian involvement of the previously formed Tortonian belt-foredeep system, a regional reinterpretation is here provided. The analysis of publicly available 2D seismic reflection lines across the upper and middle Latin Valley and 10 wells enables the identification of two main seismostratigraphic units: i) the Meso-Cenozoic neritic carbonates and ii) the upper Tortonian siliciclastic pelitic and arenaceous turbiditic associations of the Frosinone Formation. The most evident reflectors are the upper Cretaceous and upper Serravallian top paraconformities, which, due to tectonic repetition can be followed at different depths. We find that minor reflectors can be attributed to the several thrusts affecting folded Meso-Cenozoic neritic carbonates. This observation allows us, together with field and well evidences, to trace several thrust sheets characterized by a general top-to-the NE sense of shear. In a few sections from the Latin Valley (e.g. Line FR-309-80), we recognized the Meso-Cenozoic neritic carbonates being thrusted together with the Tortonian Frosinone Formation, on top of a laterally variably thick siliciclastic succession. This further syn-orogenic unit could be related to the early Messinian sandstones of the Torrice Formation, implying that out-of-sequence thrusting took place in the Latin Valley during the wedge-top sedimentation. The thin-skinned fold-and-thrust fabric is defined by en-échelon distributed thrusts, NNE- and ENE striking tear faults and minor pop-up structures often determining ideal traps for hydrocarbon and geothermal fluids. Finally, conjugated NW-striking high-angle normal faults crosscut the orogenic heritage and sets a horst and graben structure associated with continental deposition and the Volsci Volcanic Field. The limited oil exploitation over the past century has targeted only the shallower siliciclastic traps and some evidences in the shallower neritic carbornate thrust sheets. At the light of our new interpretation, the deeper carbonate units could be a new focus for hydrocarbon accumulation and may furnish targets for geothermal and/or hydrocarbon research in the area. Future work aims at quantify the Tortonian and Messinian amount of shortening by taking into consideration the adjoining Volsci Range. Finally, our findings bear implications on geodynamic reconstructions and may represent an example of the geometry and kinematic evolution of platform derived thrust sheets and similar belts worldwide associated with W-directed subduction zones.