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The occurrence of sinkhole phenomena in Italy is a prevalent and very uncertain class of geological hazards that pose a significant threat to human infrastructure and individuals. These events are characterized by their unpredictability and the challenges associated with their accurate forecasting. Both natural and anthropic factors influence the occurrence of these events; therefore, accurate identification of the above factors is critical for effective proactive and predictive efforts. The work presented in this paper refers to a collapse that occurred in a volcanic region in northern Latium (central Italy) on 31 January 2023. The area has been monitored using drones since the early stages of the sinkhole's formation and has continued to date. Then, the collapse and the neighboring area were examined via geophysical and geochemical investigations to identify potential underlying factors. Geophysical and geochemical data were combined to provide a preliminary hypothesis on the collapse's genesis. The obtained data indicate that the structural collapse can be attributable to the fluctuation in groundwater levels as well as the development of instabilities along its banks, leading to a growth in its dimensions. [ABSTRACT FROM AUTHOR]

In this research article, we propose a practical methodology for evaluating the affecting potential of detachment areas in rockfalls. Our innovative approach combines an assessment of the visibility of rockfall source areas, with reference to specific rockfall scenarios and elements at risk, considering the rockfall Susceptibility Index to Failure (SIF) of these areas. The result is the characterization of source areas through a rockfall Source Affecting Index (SAI), which considers both the morphology of the slope and the geostructural conditions of the rock walls. This information can be very useful since it aids in optimizing more in-depth analyses, as well as the placement of monitoring instruments or stabilization systems. The proposed methodology has been implemented in the open-source software QGIS through the development of an easy-to-use plugin named Ranking of the Affecting Potential of Detachment Areas in Rockfalls, or "RADAR". RADAR is designed to be used in conjunction with QPROTO, a well-known QGIS plugin for preliminary rockfall susceptibility/hazard analyses based on a visibility analysis and a simplified mechanical method. To demonstrate the effectiveness of the proposed approach, an application to a case study located in the Western Alps (Bardonecchia, Italy) is presented and discussed in the paper. [ABSTRACT FROM AUTHOR]

Criminal investigations aiming to track the route walked by missing persons and fugitives (MPFs) usually involve intelligence analysts, military planners, experts in mobile forensics, traditional investigative methods, and sniffer dog handlers. Nonetheless, when MPFs are devoid of any technological device and move in uninhabited rural areas devoid of tele cameras and densely covered by vegetation, tracking the route walked by MPFs may be a much more arduous task. In the XVIII century, the expert Georg Popp was able to link a homicide suspect to a sequence of different sites of criminal interest, located in the countryside, by studying the stains of soils found on the footwear and trousers of the suspect. In such complex cases, a very efficient approach for tracking the route walked by MPFs may consist of comparing the geological traces found on the MPFs and their belongings with soils exposed in the event scenes. In particular, the search for peculiar or rare particles and aggregates may strengthen the weight of the geological forensic evidence comparisons. A match of mineralogical, textural, and organic matter data may demonstrate the provenance of the traces from the soil of a specific site, thereby linking the MPFs to the scene of events. Based on the above, the present paper reports geological determinations accomplished for a "mediatic" casework. The results allowed a general high degree of compatibility among traces collected on the MPFs and on the soil from the scene of events to be ascertained. The most significant positive matches, based on the finding of ten peculiar and rare particles and assemblages, allowed the reconstruction of a route about 1.1 km long, as the crow flies, on the event site. Although this procedure was extremely time consuming and available only in a backwards reconstruction linked to the MPFs' findings, it was of uttermost importance in strengthening the inferences proposed, and for which other methods could not provide any information. [ABSTRACT FROM AUTHOR]

Broad mountainous areas in the western Campania (southern Italy), where young pyroclastic deposits extensively outcrop, frequently experience rainfall-induced slope movements of different degrees of mobility, causing heavy damage and fatalities. Such landslides cannot be easily mitigated, and the implementation of physically based early warning systems is still not able to predict the post-failure evolution of slope movements and the exposed areas at risk. This paper is devoted to overcoming this limit. To this end, the mechanical characterization of pyroclastic soil, carried out through an extensive laboratory testing program, is presented and compared with those of two other ashy soils of different depositional mechanisms. The results show that the depositional mode influences soil properties; to begin with, it affects the unsaturated shear strength, whose intercept of cohesion is up to 5 kPa higher in ashes of flow deposition than in airfall ash deposits. The saturated undrained soil response allowed for the identification of different levels of susceptibility to the liquefaction of pyroclastic deposits, which is one of the main factors governing the post-failure evolution of landslides. Gathering all the acquired information, including saturated and unsaturated soil shear strength, permeability function, and water retention curves, into a soil database, it was possible to present all data under a unitary framework. Finally, the implementation of the proposed flowchart for a simplified assessment of post-failure evolution to be employed in regional early warning systems can enhance our knowledge of the areas at risk. [ABSTRACT FROM AUTHOR]

Cultural heritage is one of the most exceptional resources characterizing the Italian territory. Archaeological heritage, i.e., the archaeological sites with different types of archaeological artifacts, strongly contributes to enriching the national and international cultural heritage. Nevertheless, it is constantly exposed to external factors, such as natural deterioration, anthropic impact, and climate-related hazards, which may compromise its conservation. In Italy, many archaeological areas are affected by significant soil settlements that involve a large part of monuments. This paper focuses on the landslide hazard assessment of the archaeological site of Pietrabbondante (Molise region, Italy). The impact of the expected rainfall regimes, according to the EURO-CORDEX projections, on slope stability conditions were evaluated through the application of a physically based model that couples a hydraulic and a mechanical model to evaluate slope stability evolution due to pore pressure changes. Given the unavoidable lack of knowledge of the geotechnical soil properties in an archaeological heritage area, the proposed method considered the random uncertainty of soil parameters by means of a probabilistic approach in order to assess the stability conditions in terms of probability of occurrence of a landslide. The results of this study provide a reference for the safety assessment and preventive conservation of archaeological areas characterized by high cultural value. [ABSTRACT FROM AUTHOR]

This paper presents a morphometric and structural-geomorphological approach to identifying morphotectonic features across an area underlain by lithologies that do not easily record tectonic deformations but are widely affected by seismic activity. The middle Biferno River Valley (Central Italy) was chosen as a study area. It was investigated through analyses performed from the drainage basin scale (Biferno River) to the local scale (Ponte Liscione Dam). This methodological approach was applied to investigate the impact of morphotectonic processes in the study area, providing a geomorphology-based contribution to landscape evolution. The aim of the work was to discriminate the main morphotectonic elements acting in the complex tectonic framework of the study area by means of a combination of morphometric, morphotectonic, and structural-geomorphological analyses. The resulting data allowed us to identify three main systems of tectonic elements (F1, F2, and F3), which are attributable to compressive and extensional kinematics, as already reported in previous thematic studies. The tectonic setting reflects the geodynamic framework of the Periadriatic region, as highlighted by the distribution of seismogenic sources and the historical to recent seismicity. Finally, the present work could act as a valuable scientific tool for any geomorphological studies aimed at better defining the impact of morphotectonic processes in similar tectonically active regions hosting important and strategic artificial dams. [ABSTRACT FROM AUTHOR]

The paper proposes a method to valorize abandoned mines whose traces were lost in the territory and in the collective memory. We selected two case studies in the Umbria region (central Italy) that were used as examples. The evidence of the presence of lignite mines on the Upper Tiber River Valley (northern Umbria) has been completely erased, and since they were located in rural areas, they represent an interesting challenge regarding recovering the memory of the places and proposing a no-longer-existent site as a geosite. The recovery and valorization of historical documents of the two lignite mines (Caiperino–Terranera and Carsuga) and their conversion into a digital format was carried out before constructing a geolocalized database in a GIS environment. This framework is the starting point for a promising dissemination process via a digital media app, using multimedia contents as video, 3D models and the principles of augmented reality (AR) to enhance the touristic or didactic experience and promote the cultural heritage of the territory by keeping the memory of 'ghost places'. [ABSTRACT FROM AUTHOR]

Historical seismology retrieves information about the effects of earthquakes that occurred in the past, mostly regarding the damage, but also on environmental effects. In this paper, we describe the methodology of our research on earthquake-induced hydrological effects, which have been long observed and documented, and are among the most outstanding coseismic phenomena. The method of research follows two distinct paths, depending on whether the investigated event occurred before or after the end of the 18th Century. For the most ancient events, we present examples of historical accounts, local reports, private letters, and diaries, in which the information of interest is often hidden within broader descriptions and mentioned as a minor curiosity. On the contrary, for more recent earthquakes, the research benefits from the growing interest in naturalistic observations that marked the onset of the 19th Century, and is achieved through detailed descriptions, journals, seismic postcards, and through the first systematic collections of instrumental data. Finally, we describe a possible method of classification of the hydrological data and show an analysis of the potential applications and outcomes of this type of research. [ABSTRACT FROM AUTHOR]

This paper investigates the possibility to detect the short-time evolution of the slow-moving Vomice earth flow, located in the northeastern sector of the Calabria region (South Italy), by combining the information obtained from two different drone flights, carried out in February 2019 and June 2022, with field surveys. The obtained results consisted of delimiting all landslide bodies constituting the Vomice earth flow, detecting landslide types and the state of activity, as well as identifying spatial and volumetric changes. The obtained results showed that depletion and transition zones of the Vomice earth flow are active, while the accumulation zone appears prevalently dormant. Particularly, in the analyzed period, the depletion zone was characterized by local collapses of the main scarps where several slides evolving in earth flows caused more than 20 m of retrogressive fail upslope. The maximum elevation changes observed in these zones were about ±5 m. The volume of the material mobilized by mass movements was about 114.2 × 103 m3, whereas the volume of the accumulated material was approximately 92.7 × 103 m3. The transition zone was affected by several slow earthflows that re-mobilized the displaced material located in the middle portion of the landslide and reached the accumulation zone. Overall, the results of this study demonstrated the practicality and feasibility of using UAV tools for detecting the short-time evolution of a large landslide. [ABSTRACT FROM AUTHOR]

On 27–28 July 2019, in a catchment of the Mt. Amiata area (Italy), an extreme rainfall induced a debris flow, which caused a channeled erosive process just upstream of the Abbadia San Salvatore village, the obstruction of a culvert at the entrance to the urban area, and the subsequent flooding of the village. In this paper, we present the back analysis of this event. The complexity of this case study is due to several peculiar characteristics, but above all, to the clogging of the culvert, a phenomenon difficult to simulate numerically. The methodology used for the reconstruction of the event is based on a multidisciplinary approach. A geological field investigation was carried out to characterize the catchment and assess the availability of debris. Then, a cascade of numerical models was employed to reconstruct the debris flow: the FLO-2D software was used to model the runoff along the hydrographic network while the mobile-bed debris flow TRENT2D model, available through the WEEZARD system, was used to quantify both the erosion and deposition processes that occurred during the event. To simulate the culvert clogging, a novel modelling procedure was developed and applied. Despite the challenging framework, the results, in terms of debris volume, erosion rates, deposition area, and timing of the culvert obstruction, agree reasonably well with the observed data. It is worth noticing that these results were obtained mainly using parameters set a priori, namely calibrated on a physical basis. This proves that the proposed methodology is robust and effective, with good predictive capability. Therefore, it may be considered, according to the European Union (EU) Flood Directive, an "appropriate practice and the best available technology that does not imply excessive costs" to support predictive hazard mapping of situations as the one here considered. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of mild explosive activity is a fundamental tool for hazard assessment at open conduit volcanoes. This is a particularly critical task for Etna volcano. Etna is in fact characterized by frequent, mild explosive activity, punctuated by lava flows and paroxysmal events ('lava fountains'), which, because of their greater impact, have been the main target for hazard studies, whereas more frequent Strombolian activity has been overlooked. As a result, their impact and associated hazards have been never quantified, despite the extensive monitoring and surveillance activities carried out on this volcano. In this paper, we analyze video recordings of a sequence of Strombolian explosions occurring at the summit craters of Mt. Etna, in Italy, in February 2020. Data were also integrated with a petrographic analysis of collected samples, and drone surveys were performed at the same time as the video recordings. We estimate the frequency of explosions (20–12 per min); particle exit speeds (1–50 m/s), and erupted mass (100–102 kg) of those explosions. A very regular, small-scale activity (marked by a single burst of gas breaking the magma free surface into bombs and lapilli fragments) was occasionally punctuated by larger explosions, (at least one every 5 min), with a longer duration, fed by larger magma volumes, and consisting of two to three distinct pulses followed by a stationary phase. We found that the repose times between explosions follows a log logistic distribution, which is in agreement with the behavior of open vent explosive activity. The four largest explosions of the sequence were analyzed in detail: they emitted particles with median diameters (Mdphi) ranging from −10.1 to −8.8 phi, with bimodal distributions. [ABSTRACT FROM AUTHOR]

Between August 2016 and January 2017, a very energetic seismic sequence induced substantial horizontal and vertical ground displacements in the Central Italian Apennines. After this event, the Italian Military Geographical Institute (IGM), owner and manager of the Italian geodetic networks, executed several topographic surveys in the earthquake area in order to update the coordinates of vertices belonging to the IGM95 geodetic network. The measurements began in the areas where the most significant deformation occurred: the localities of Amatrice and Accumoli, in the Rieti Province, and the area covering Norcia and Castelluccio, in the Province of Perugia, all the way to Visso (Province of Macerata). The activities described in this paper focused on the updated measurement of the IGM95 network points through GNSS and the restatement of extensive parts of the high precision geometric lines that were levelled until reaching stable zones. This unprecedented amount of data was used for a new geological interpretation of the seismic sequence, which confirms some of the previous hypotheses of the scientific community. In the analyzed territory, the latest estimate of the geodetic position points has allowed for an accurate determination of the east and the north and of the altitude components of the displacement induced by the earthquake through a comparison with the previous coordinates. The results confirm that the seismicity was induced by normal faults system activity. Still, they also indicate the possible influence of a significant regional thrust that conditioned the propagation of the seismicity in the area. The obtained maps of the displacement are coherent with other geodetic works and with a rupture propagation driven by the documented geotectonic structure. [ABSTRACT FROM AUTHOR]

Despite the concrete evidence of human responsibilities with the ongoing environmental crisis, tangible changes toward low disaster-risk development models are slow in coming and delayed in implementation. This paper discusses the principles of geoethics underpinning flood risk reduction by analyzing the results of the EU project LIFE PRIMES (Preventing flooding RIsks by Making resilient communitiES). Through the administration of a questionnaire, issues of flood literacy, effective communication and individual responsibility concerning flood hazard and exposure were investigated. Directly engaging local communities, the LIFE PRIMES project appears to have increased citizens attention toward environmental ethics, thus providing an encouraging perspective for appropriate human–environment interaction. [ABSTRACT FROM AUTHOR]

Many of the urban settlements in Central Italy are placed nearby active faults and, consequently, the ground motion evaluation and seismic site effects under near-fault earthquakes are noteworthy issues to be investigated. This paper presents the results of site investigations, the seismic site characterization, and the local seismic response for assessing the effects induced by the Mw 6.7 2 February 1703, near-fault earthquake at the Madonna delle Fornaci site (Pizzoli, Central Italy) in which notable ground failure phenomena were observed, as witnessed by several coeval sources. Even though recent papers described these phenomena, the geological characteristics of the site and the failure mechanism have never been assessed through in-situ investigations and numerical modeling. Within a project concerning the assessment of soil liquefaction potential and co-seismic ground failure, deep and shallow continuous core drilling, geophysical investigations and in-hole tests have been carried out. Subsequently, the geotechnical model has been defined and the numerical quantification of the different hypotheses of failure mechanisms has been evaluated. Analyses showed that liquefaction did not occur, and the excess pore water pressure induced by the shaking was not the source of the ground failure. Therefore, it was hypothesized that the sinkhole was likely caused by earthquake-induced gas eruption. [ABSTRACT FROM AUTHOR]

For crenulate-shaped bays, the coastal outline assumes a specific shape related to the predominant waves in the area: it generally consists of a tangential zone downcoast and a curved portion upcoast. Many coastal engineers have attempted to derive an expression of the headland bay shapes that emerge when a full equilibrium is reached (stable or dynamic). However, even though models for static equilibrium bays exist, they are merely of an empirical kind, lacking further insight on relationships between incident wave characteristics and beach shape. In addition, it is commonly believed that shoreline profiles tend to follow wave fronts, but this has been never fully verified. In this paper, we investigate a possible correlation between static equilibrium profiles and wave front shapes. Numerical experiments have been performed using the MIKE 21 Boussinesq Wave module, and the generated wave fronts have been compared to the hyperbolic-tangent equilibrium profile. A thoughtful analysis of results revealed that a single-headland equilibrium profile is merely the wave front translated perpendicularly to the wave direction at the headland tip, without any influence of wave period or in wave direction. A new function called the "wave-front-bay-shape equation" has been obtained, and the application and validation of this formula to the case-study bay of the Bagnoli coast (south-west of Italy) is described in the paper. [ABSTRACT FROM AUTHOR]

The paper describes the three-dimensional numerical model of Ville San Pietro, an Italian village subject to slope movements causing damage. The church (dating back to 1776), which is the most significant building of the area, is modelled too. The information from geotechnical and geophysical surveys on field are used to define the model geometry and the soil properties. A finite element code is adopted to simulate the slope behavior in occurrence of water table fluctuations, detected by piezometers, and to evaluate the slope displacements and stability. The validation of the model is carried out using the inclinometer and interferometry measures and by on-site inspections. The model demonstrated a good ability to simulate the slope behavior during the raising and lowering of the water table. The critical areas computed by the numerical code are in good accordance to the actual portions affected by soil displacements and damages. The modelling presented in this paper is crucial for future analyses that will take advantage of an innovative monitoring system, which will be installed on site. [ABSTRACT FROM AUTHOR]

Archaeological areas in the mountain region of central Italy can be seriously threatened by geological hazards, and efforts are required to preserve cultural heritage. The Lucus Angitiae is a pre-Roman site located along the western edge of the Fucino Basin, the largest continental depression of central Apennines. The carbonate slope overhanging the area is affected by active rockfall processes from two main rock escarpments. In this paper, rockfall assessment was pursued through a 3D kinematic modelling, performed by adopting a probabilistic approach. Specific attention was dedicated to the choice and calibration of the input data, based on field evidence and a literature review. Two different sizes of wedge-shaped rock blocks were identified on rock escarpments, and specific stability analyses were performed. Sensitivity analyses accounting for possible triggering factors, such as water pressure increase and seismic action, were also carried out, together with an investigation of the seismological characteristics of the area. The results of the numerical simulations were used to design effective countermeasures in the framework of a mitigation plan for protection of the archaeological site. Finally, clues of gravity-driven slope deformations at the slope scale were documented, framing the rockfall process in a wider geological scenario. [ABSTRACT FROM AUTHOR]

Geostructural rock mass surveys and the collection of data related to discontinues provide the basis for the characterization of rock masses and the study of their stability conditions. This paper describes a multiscale approach that was carried out using both non-contact techniques and traditional support techniques to survey certain geometrical features of discontinuities, such as their orientation, spacing, and useful persistence. This information is useful in identifying the possible kinematics and stability conditions. These techniques are extremely useful in the case study of the Elva valley road (Northern Italy), in which instability phenomena are spread across 9 km in an overhanging rocky mass. A multiscale approach was applied, obtaining digital surface models (DSMs) at three different scales: large-scale DSM of the entire road, a medium-scale DSM to assess portions of the slope, and a small-scale DSM to assess single discontinuities. The georeferenced point cloud and consequent DSMs of the slopes were obtained using an unmanned aerial vehicle (UAV) and terrestrial photogrammetric technique, allowing topographic and rapid traditional geostructural surveys. This technique allowed us to take measurements along the entire road, obtaining geometrical data for the discontinuities that are statistically representative of the rock mass and useful in defining the possible kinematic mechanisms and volumes of potentially detachable blocks. The main purpose of this study was to analyse how the geostructural features of a rock mass can affect the stability slope conditions at different scales in order to identify road sectors susceptible to different potential failure mechanisms using only kinematic analysis. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of cliff stability and proposes a geomorphological zonation of a cliff using a sector of the Posillipo promontory (named the Coroglio-Trentaremi sea cliff, Italy), in the Campi Flegrei coastal area, as a case study. A detailed geological and geomorphological analysis was carried out, by combining field work with analysis of detailed scale topographic maps, orthophoto, and stratigraphical data from deep boreholes. Field and borehole data, together with structural data collected in seven different stations along the cliff, allowed us to derive six geological cross-sections and to reconstruct the complex stratigraphical and structural setting of the cliff. Geomorphological analysis focused on the detection of the main geomorphological factors predisposing to cliff instability. We selected the most significant factors and divided them into two groups: factors influencing landslide intensity and factors influencing cliff instability. Then, by means of a heuristic approach, we constructed a matrix that was used to derive a map showing the geomorphological zonation of the sea cliff. This map may enable to development of a reliable scenario of cliff instability and consequent retreat, which may be useful either to plan intervention works in the most critical areas or to organize prevention plans aimed at risk mitigation. [ABSTRACT FROM AUTHOR]

The present research paper properly focuses on the dynamics and failure mechanisms of the masonry "Apennine Church" of Santissimo Crocifisso in Pretare, municipality of Arquata del Tronto in the province of Ascoli Piceno (Marche region, Central Italy). Such a peculiar structural type traditionally characterizes the intense seismic area of Central Italy, unfortunately almost totally damaged by the recent shock sequence of 2016. Advanced numerical modeling through discontinuous and continuous approaches were here utilized to have an insight into the dynamic properties and behavior of the structure under strong nonlinear dynamic excitations. In the discrete element approach, the non-smooth contact dynamics method, implemented in LMGC90©, was applied, adopting a full 3D detailed discretization. The church was schematized as an arrangement of rigid blocks, subjected to sliding by friction and perfect plastic collisions, with a null restitution coefficient. In the finite element approach, the concrete damaged plasticity model available in Midas FEA NX© was involved. This model allows reproducing the tensile cracking, the compressive crushing, and the degradation of the material under cyclic loads. Finally, the numerical analyses provided a valuable picture of the actual behavior of the church, thus giving useful hints for future strengthening interventions. [ABSTRACT FROM AUTHOR]

Knowledge of a territory is an essential element in any future planning action and in appropriate territorial and environmental requalification action planning. The current large-scale availability of satellite data, thanks to very high resolution images, provides professional users in the environmental, urban planning, engineering, and territorial government sectors, in general, with large amounts of useful data with which to monitor the territory and cultural heritage. Italy is experiencing environmental emergencies, and coastal erosion is one of the greatest threats, not only to the Italian heritage and economy, but also to human life. The aim of this paper is to find a rapid way of identifying the instantaneous shoreline. This possibility could help government institutions such as regions, civil protection, etc., to analyze large areas of land quickly. The focus is on instantaneous shoreline extraction in Ortona (CH, Italy), without considering tides, using WorldView-2 satellite images (50-cm resolution in panchromatic and 2 m in multispectral). In particular, the main purpose of this paper is to compare commercial software and ACM filters to test their effectiveness. [ABSTRACT FROM AUTHOR]

This paper aims to describe the seismic-driven multi-hazard scenario of the Lake Campotosto artificial basin (Abruzzo Region, Central Italy), and it can represent a preparatory study for a quantitative multi-hazard analysis. A comprehensive multi-hazard scenario considers all the effects that can occur following the base ground shaking, providing a holistic approach to assessing the real hazard potential and helping to improve management of disaster mitigation. The study area might be affected by a complex earthquake-induced chain of geologic hazards, such as the seismic shaking, the surface faulting of the Gorzano Mt. Fault, which is very close to one of the three dams that form the Lake Campotosto, and by the earthquake-triggered landslides of different sizes and typologies. These hazards were individually and qualitatively analyzed, using data from an engineering-geological survey and a geomechanical classification of the rock mass. With regard to the seismic shaking, a quantitative evaluation of the seismic response of the Poggio Cancelli valley, in the northern part of Lake Campotosto, was performed, highlighting different seismic amplification phenomena due to morphologic and stratigraphic features. Some insights about the possible multi-hazard approaches are also discussed. [ABSTRACT FROM AUTHOR]

This paper presents a chemical-mineralogical characterization of construction materials from medieval Renaissance buildings of Ferrara (NE Italy) to provide an insight into the nature and provenance of the raw materials used. Biagio Rossetti was an Italian architect and urbanist from the city of Ferrara. From 1483, he was the architect of the Duke of Ferrara Ercole I d'Este who in 1492 assigned him the project of enlarging the city of Ferrara. Biagio Rossetti is still famous because he designed and built many notable palaces and churches in Ferrara, e.g., the Palazzo Roverella, the monastery of Santa Maria delle Grazie and the renovation of the church of San Andrea. To date, only the first two historic buildings are still in use and consequently restored, while the church of San Andrea has been abandoned over the years and the remains have been subject to decay. Different kinds of samples (bricks, cotto, plaster and mortars) were collected from the three sampling sites and analyzed in X-ray fluorescence and X-ray diffractometer to investigate the construction materials through the evaluation of their chemical composition, historic building activity and degradation degree. These investigations should provide knowledge useful for restoration and conservation processes. [ABSTRACT FROM AUTHOR]

In this paper, a study concerning the soil liquefaction potential in the city of Catania is presented. The stress-based liquefaction analysis framework for cohesionless soil includes a function that describes fundamental aspects of dynamic site response, i.e., the shear stress reduction coefficient, rd, which depends on several factors (depth; earthquake and ground motion characteristics; dynamic soil properties). Various relationships of rd are reported in literature because of the importance of assessment of CSR. Herein, new variations of rd with depth have been obtained using different deterministic earthquake scenarios as input motion. The relationships are based on large numbers of site response analyses for different site conditions. The new relationships obtained have been used for the evaluation of the liquefaction potential in the area of the Catania Harbour. The liquefaction resistance has been evaluated by the horizontal stress index (KD) from seismic dilatometer Marchetti tests (SDMTs). Various correlations were developed to estimate the CRR from KD, expressed in form of CRR-KD curves to differentiate between liquefiable and non-liquefiable zones. In this study three different CRR-KD curves have been used. [ABSTRACT FROM AUTHOR]

This paper aims to present, through a photographic reportage, the current state of rebuilding of the most devastated villages by the earthquake that hit the Southern Italy on 23 November 1980, in Irpinia-Basilicata. The earthquake was characterized by magnitude Ml = 6.9 and epicentral intensity I0 = X MCS. It was felt throughout Italy with the epicenter in the Southern Apennines, between the regions of Campania and Basilicata that were the most damaged areas. About 800 localities were serious damaged; 7,500 houses were completely destroyed and 27,500 seriously damaged. The photographic survey has been done in 23 towns during the last five years: Castelnuovo di Conza, Conza della Campania, Laviano, Lioni, Santomenna, Sant'Angelo dei Lombardi, Balvano, Caposele, Calabritto and the hamlet of Quaglietta, San Mango sul Calore, San Michele di Serino, Pescopagano, Guardia dei Lombardi, Torella dei Lombardi, Colliano, Romagnano al Monte, Salvitelle, Senerchia, Teora, Bisaccia, Calitri and Avellino. Forty years after the 1980 earthquake, the photographs show villages almost completely rebuilt with modern techniques where reinforced concrete prevails. Only in few instances, the reconstruction was carried out trying to recover the pre-existing building heritage, without changing the original urban planning, or modifying it. We argue that this photography collection allows to assess the real understanding of the geological information for urban planning after a major destructive seismic event. Even more than this, documenting the rebuilding process in a large epicentral area reveals the human legacy to the natural landscape, and our ability, or failure, to properly interpret the environmental fate of a site. [ABSTRACT FROM AUTHOR]

The recent signs of reawakening at Campi Flegrei caldera (Southern Italy) received a great deal of attention due to the issues related to the volcanic risk management in a densely populated area. This paper explores relations between ground deformations, seismicity and geochemical time series in the time span 2004–2016. The aim is to unravel primary processes of unrest and the related indicators which may change in time. Data structure and interactions among variables were examined applying the clustering analysis, the correlations and the Granger causality test. The hierarchical agglomerative clustering detected two sub-periods which were further investigated. In both sub-period causal links were observed between variables while correlations did not appear and vice versa. Thus, well established formal approaches are required to study causal relations. Granger test results indicate that during 2004–2011 the awakening unrest could be mainly ascribed to hydrothermal system pressure fluctuations, probably induced by deep-rooted fluids injection, and that ground deformation together with CO2/H2O appears the most suitable geo-indicators. The 2011–2016 sub-period is characterized by enhanced dynamical connectivity. Granger test results suggest that the unrest is driven by a more localized and shallower thermohydromechanical engine. CO/CO2, He/CH4 and ground deformation velocity are mutually interacting appearing the most suitable geo-indicators. [ABSTRACT FROM AUTHOR]

Stiff jointed clays (SJC) belong to so-called structurally complex formations in which the macroscale features of the deposit, that is the pattern of discontinuities affecting the soil mass, influence its response at the scale of engineering works. Such peculiar response was largely recognized during the excavation works carried out for the construction of two new road segments in southern Italy, where several structurally conditioned instability processes were triggered during excavation works. These phenomena mainly involved the Plio-Pleistocene marine clayey formation outcropping along the East coast of the Calabria region, where it constitutes most of the hills interested by construction works. Under a geotechnical perspective, the SJC-formation exhibits good mechanical characteristics at the scale of samples but, if considered as a whole, its behaviour is governed by the presence of discontinuities along which strength is typically at residual. Building on the author's experience of some exemplary failure events, this paper aims at defining possible design strategies to minimize the risk of adverse and unexpected instability phenomena during construction in structurally complex formations. Design strategies oriented at reducing and possibly avoiding stress releases in the zone of influence were found to be most effective at preventing failures or restoring safety after the occurrence of a failure event. [ABSTRACT FROM AUTHOR]

Pyroclastic soils are widespread in the world. In particular, they cover a great part of Campania, a densely populated country of Southern Italy, where some distinct volcanic centers are present. In these soils, precipitations can trigger fast flow-like landslides causing destruction and loss of human lives. The movement style, the high velocity and the long run-out of these landslides are an indication of the occurrence, in the saturated soil mass, of mechanisms of undrained instability due to the inability of soil to sustain the deviator stress related to the slope condition. This paper reports the results of a wide experimental laboratory program carried out on a volcanic ash, which recently has been the seat of a killer landslide, stressing the factors that govern the undrained response of these materials. [ABSTRACT FROM AUTHOR]

This paper reports the results of a field-based structural investigation of a well-exposed paleo-accretionary prism, which experienced complex deformation in a low-grade metamorphic setting. Field analyses focused on the description of structural fabrics, with the main emphasis upon parameters like the orientation, style and kinematics of foliations, folds and shear zones. We address the research to the south-westernmost part of the Alpine chain, the Ligurian Alps, where, despite their origin as turbidite sequences deposited into the closing Alpine Tethys Ocean, the Helminthoid Flysch Nappes are presently distributed in the outer part of the chain, above the foreland. The new dataset highlights different deformation patterns related to the different spatial distribution of the flysch units. This regional-scale partitioning of strain is hence associated with progressive deformation within a two-stage geodynamic evolution. Correlations among the different orogenic domains allow the proposal of a kinematic model that describes the motion of the Helminthoid Flysch from the inner to the outer part of the orogen, encompassing the shift from subduction- to collision-related Alpine geodynamic phases. [ABSTRACT FROM AUTHOR]

The city of Taranto in the south of Italy is one of the areas declared as "at high risk of environmental crisis" by the Italian government because it represents one of the most complex industrial sites in Europe, located near urban areas of high population density. The rich ecosystem of the Mar Piccolo basin, located at north of Taranto, started exhibiting unconfutable signs of environmental pollution, confirmed by the high concentrations of organic and inorganic contaminants. Among the different aspects involved in the environmental studies aiming at the basin remediation, this paper focuses on submarine sediments and reports some results of the geotechnical laboratory investigations which made also use of non-standard equipment and revised procedures for data interpretation in order to take account of the sediments' contamination and heterogeneities. The geotechnical laboratory tests show that, despite the Mar Piccolo recent Holocene sediments having similar origin and composition to those of the Sub-Apennine clay basic formation, their behavioral facets appear to be altered by the presence of contaminants of both natural and anthropogenic origin. Results of washing tests are also presented as a first attempt to quantify the effects of chemo-mechanical coupling processes on the plasticity properties of the shallow sediments. [ABSTRACT FROM AUTHOR]

The present paper deals with a field experiments on evaporite rock samples and groundwater investigations in the Quinis test site, a hamlet of the Enemonzo municipality in NE Italy, were sinkholes occurred in the past and are still occurring causing severe damage to the existing infrastructures. The area is characterised by a Carnian evaporitic bedrock made of gypsum and anhydrite mantled by alluvial and colluvial deposits. In order to evaluate the loss of weight and volume of the subcropping evaporites as responsible for sinkholes, a field-experiment was carried out. Inside seven piezometers, at different depths, evaporitic rock samples were exposed to the naturally occurring variable climatic conditions such as degree of humidity, different air flow and hydrodynamic. The rock samples were installed at the beginning of April 2017 in the dry sections of piezometric tubes, in the vadose zone and in the phreatic zone. Data related to water level fluctuations were recorded by using data-logger devices and highlight significant changes in the water table. After 13 months of data recording (May 2018), rock samples were removed, reweighted and the volume loss measured. In addition, water from piezometer-experiment, representative of the groundwater circulation, were collected at different depths. The obtained results indicate that rock sample reduction is dependent on the hydrological regime and water chemistry and not on the number of days during which the samples remained submersed. In particular, the water geochemistry highlights the possible role in gypsum/anhydrite dissolution due to NaCl water admixing in a complex scenario. In additional, the geochemical data highlight the occurrence of some potentially toxic elements (As, Fe, Mn) at concentrations of concern in some water. This approach represents a novel contribution in the study of karst hazard in evaporites adding a tile to the knowledge of the fast evolutionary processes which cause sinkhole formation. [ABSTRACT FROM AUTHOR]

The stability of high rock slopes is largely controlled by the location and orientation of geological features, such as faults, folds, joints, and bedding planes, which can induce structurally controlled slope instability. Under certain conditions, slope kinematics may vary with time, as propagation of existing fractures due to brittle failure may allow development of fully persistent release surfaces. In this paper, the progressive accumulation of brittle damage that occurred prior to and during the 2014 San Leo landslide (northern Italy) is investigated using a synthetic rock mass (SRM) approach. Mapping of brittle fractures, rock bridge failures, and major structures is undertaken using terrestrial laser scanning, photogrammetry, and high-resolution photography. Numerical analyses are conducted to investigate the role of intact rock fracturing on the evolution of kinematic freedom using the two-dimensional Finite-discrete element method (FDEM) code Elfen, and the three-dimensional lattice-spring scheme code Slope Model. Numerical analyses show that the gradual erosion of clay-rich material below the base of the plateau drives the brittle propagation of fractures within the rock mass, until a fully persistent, subvertical rupture surface form, causing toppling of fault-bounded rock columns. This study clearly highlights the potential role of intact rock fracturing on the slope kinematics, and the interaction between intact rock strength, structural geology, and slope morphology. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a stochastic model to generate sub-hourly rainfall events at a given point. Historical events used as the input have been extracted by the sub-hourly rainfall series available for a defined rain gauge station based on a fixed inter-event time and selected if their average intensity was larger than a critical fixed one. The sub-hourly events generated by applying the proposed methodology are completely stochastic and their main characteristics, i.e., shape, duration and average intensity, have been derived as a function of the statistics of the historical events analyzed. In order to characterize the shape, dimensionless hyetographs have been derived. They have been statistically modelled by using the Beta cumulative distribution. Average intensity and duration of the historical events were first modelled separately by fitting several probability distributions and selecting the best one using the more common statistical criteria. Then, their correlation was modelled using the Frank's copula. In order to test the methodology, two sites in Sicily, Italy, where 10 min' recorded rainfall data were available, were analyzed. Finally, comparison between the statistics of the simulated events and those of the measured data demonstrates the good performance of the model. [ABSTRACT FROM AUTHOR]

In the present paper, we analyse ground tilt and seismicity at Campi Flegrei caldera and Ischia Island, two volcanic areas located in the south of Italy. These areas have been well studied for many years from a petrological, volcanological and geophysical view point. Moreover, due to the high seismic and volcanic risk for the populations living there, they are continuously monitored by networks of geophysical and geochemical sensors. We summarize the most important results that we obtained so far, concerning the observations of relationships between seismic activity and ground tilt anomalies, focusing on the time interval 2015–2018. First, we present a detailed description of the tiltmeter and seismic networks in both the investigated areas, as well as their development and improvement over time that has enabled high quality data collection. From the joint analysis of the seismic and borehole tiltmeter signals, we often notice concurrence between tilt pattern variations and the occurrence of seismicity. Moreover, the major tilt anomalies appear to be linked with the rate and energy of volcano-tectonic earthquakes, as well as with exogenous phenomena like solid Earth tides and hydrological cycles. The analysis that we present has potential applicability to other volcanic systems. Our findings show how the joint use tilt and seismic data can contribute to better understanding of the dynamics of volcanoes. [ABSTRACT FROM AUTHOR]

The design of countermeasure works to mitigate landslide risk needs to deal with the multiple unknowns that are linked with soil properties, distribution and rheology. Most of the time, the degree of definition of all these elements is low. Through landslide monitoring, it is possible to acquire signals from the landslide that carry synthetic information about its dynamic. Thus, if it is possible to define a model that is able to link the landslide displacements with the triggering factors and to predict them consistently, that model may be used to evaluate the effect of a countermeasure work directly, bypassing the geomechanical uncertainty. In this paper, an example application of this approach is described. The displacements of a landslide located in North East Italy are connected with the water discharge of the small stream the crosses the landslide body. A countermeasure work that intercepts the discharge of the torrent is expected to reduce the landslide displacements of approximately 70%, with lower costs of construction and smaller impacts on the environment and landscape with respect of other types of structural mitigation works such as slope reprofiling and large retaining walls. [ABSTRACT FROM AUTHOR]

During recent years, the availability of innovative monitoring instrumentation has been a fundamental component in the development of efficient and reliable early warning systems (EWS). In fact, the potential to achieve high sampling frequencies, together with automatic data transmission and elaboration are key features for a near-real time approach. This paper presents a case study located in Central Italy, where the realization of an important state route required a series of preliminary surveys. The monitoring system installed on site included manual inclinometers, automatic modular underground monitoring system (MUMS) inclinometers, piezometers, and geognostic surveys. In particular, data recorded by innovative instrumentation allowed for the detection of major slope displacements that ultimately led to the landslide collapse. The implementation of advanced tools, featuring remote and automatic procedures for data sampling and elaboration, played a key role in the critical event identification and prediction. In fact, thanks to displacement data recorded by the MUMS inclinometer, it was possible to forecast the slope failure that was later confirmed during the following site inspection. Additionally, a numerical analysis was performed to better understand the mechanical behavior of the slope, back-analyze the monitored event, and to assess the stability conditions of the area of interest. [ABSTRACT FROM AUTHOR]

The identification of the triggering mechanism of rainfall-induced, shallow landslides requires a complete understanding of the hydro-mechanical response of soil, which can be represented through the trends of the degree of soil saturation. In this paper, multiple annual cycles of soil saturation obtained through field monitoring were used to validate an empirical model based on climate data. Both field measurements and model outputs were used to conduct simplified slope stability analysis to evaluate the model chain capability in predicting the temporal occurrence of shallow failures. Field data were collected on a testsite slope located in Oltrepò Pavese (Northern Italy), where a shallow landslide occurred during the monitoring period. The experimental trends of the degree of saturation at various depths in the soil profile were compared with the calculated values and showed good agreement. Landslide triggering is reached when the soil is completely saturated. Both measured and modeled trends of soil saturation correctly identified the triggering time of the shallow landslide and the depth of the sliding surface, 1.0 m below the ground surface, in the test slope. The obtained results indicated the possibility of extending this approach for theassessment of the initiation time and the depth of shallow landslides, particularly for preliminary susceptibility evaluations, based on widely available climate data. [ABSTRACT FROM AUTHOR]