Patrizia Capizzi

Geophysical methods (in particular ERT technique) constitute an excellent tool for the detection of buried cavities. However the integration approach of e different geophysical methods could minimize the ambiguity of geophysical interpretation of the buried cavity. The technique of electrical tomography has been joined to the technique of seismic refraction tomography in order to obtain more robust interpretations. Many tests have been carried out using synthetic data and experimental ones. It was finally used a statistical approach based on cluster analysis of the P-wave velocity, the density of the seismic rays and the electrical resistivity of the synthetic and experimental models. Distribution maps of the cluster in multi-space were built, allowing to better define and interpret the anomalies of the subsoil

Recently, the use of microtremor techniques for subsoil investigation has increased significantly. The HVSR (Horizontal to Vertical Spectral Ratio) technique allows, in many cases, to obtain a seismo-stratigraphic reconstruction of the subsoil and to identify areas with similar seismic behavior. However, the stratigraphic interpretation of the HVSR peaks still remains a subjective choice and linked to a priori information. A non-hierarchical centroid-based algorithm was modified to group HVSR peaks of different measurements that can be attributed to the same generating seismic discontinuity. Some tests performed have shown that the proposed algorithm produces valid results even in the absence of a priori information to evaluate the choice of the optimal grouping. The results obtained for HVSR measurements acquired in the city of Modica (Italy) are presented. The cluster analysis of these data and the information on the lithologies outcropping in the area made it possible to reconstr...

The church of S. Mary of the Admiral in Palermo, known as “La Martorana” and very famous for its Byzantine mosaics, has been a World Heritage site since 2015. The mosaic system of the church includes several groups of figures and scenes from the life of the Virgin Mary. From the western part of the ancient church only two mosaics survive, detached from their original position, and are now located in two internal chapels. On the occasion of several restoration works, these two mosaic panels were investigated with non-invasive techniques, in order to provide diagnostic support to the restoration and consolidation interventions. The investigations were aimed at detecting any air pockets that could cause the detachment of the tesserae or of possible differences between cement mortars under the tesserae. For this purpose, the integrated use of two non-invasive techniques namely infrared thermography (IRT) and ground penetrating radar (GPR) was considered. The joint analysis of IRT and GP...

Misterbianco is located on the southern flank of Mt. Etna (Unesco site), in eastern Sicily (Italy). This site, also known as Monasterium Album, has a long and tormented history linked with volcanic activity of Mt. Etna and regional seismicity. This site received much attention in the 2000s when excavation works brought to light a 14th century church remains below the thick layer of the 1669 lava. This study documents the first diagnostic multidisciplinary survey performed at this site 350 years after the eruption: the investigations were performed by using techniques such as ground-penetrating radar, infrared thermography, a terrestrial laser scanner and a drone survey to analyze the site’s topography, to adequately map the hidden structures inside the building and to identify fractures and deformations in the church. Starting from the site history, we present the results of the multidisciplinary approach aimed at reconstructing the historical events that led to the damage in the ch...

near surface seismostratigraphic modeLLing of the bandita pLain in paLermo town (itaLy) from integrated anaLysis of hvsr and stratigraphic data R. Martorana1, M. Agate1, P. Capizzi1, F. Cavera1, A. D’Alessandro2 1 Dipartimento di Scienze della Terra e del Mare (DiSTeM), Università degli Studi di Palermo, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia, Centro Nazionale Terremoti, Roma, Italy

MULTIVARIATE MODELLING OF GEOPHYSICAL TOMOGRAPHIC DATA TO IDENTIFY A TECTONIZED AREA P. Capizzi1,2, A. Carollo1, M. Gasparo Morticelli1, R. Martorana1,3, A. Sulli1,3 1 Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare (DiSTeM), Palermo, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italy 3 Istituto Nazionale di Geofisica e Vulcanologia, Centro Nazionale Terremoti, Roma, Italy

An application of HVSR inversion is presented in order to verify the effectiveness of this technique for purposes of reconstruction of the buried geological setting where stratigraphic constraints are available. Specifically, the reconstruction of the stratigraphy in the studied area has been obtained by a seismic-stratigraphic three-dimensional modeling. This allowed for geophysical and geognostic data derived from surveys carried out during this study, as well as previously by the municipality of Palermo.

An integrated research on the hinge zone between northern Sicily and its Tyrrhenian off-shore has been carried out, by means of structural, seismological and statistical analyses. The main structural features of the area are represented by both NWSE to W\u2013E striking right-lateral and N\u2013S to NE-SW striking leftlateral fault systems, responsible of uplifting (restraining) and subsiding (releasing) zones. Within this hinge zone the seismicity is mainly located between 10 and 20 km of depth and clustered according to the orientation of the outcropping fault systems. The brittle strain partitioning related to a right-lateral simple shear zone has been reconstructed in the onshore sector, while in the offshore the structural setting has been inferred from morpho-bathymetric and geological maps of the southern Tyrrhenian basin. Moreover, in this latter zone, a new seismological study has been carried out on a part of 2002 seismic sequence (more than 600 events), using a database obtained by merging the CSI 1.1 catalogue of INGV and new data recorded by 7 three-components stations of a temporary network installed by INGV. These seismic events, occurred between September and December 2002, have been relocated using an eight layered velocity model optimized for the southern Tyrrhenian. The focal mechanisms of 40 events have been determined. The Coulomb stress changes related to the main event have been also calculated. The general geometric characters of the whole set of investigated parameters well fit the simple shear deformational style reconstructed of the onshore study zone. Moreover, both focal mechanisms and principal stress components of about 100 events of 1992-1993 Pollina seismic swarm (Eastern Madonie Mts.) has been also carried out. The main focal mechanisms typologies and stress axis trends show a good agreement with the seismogenic volume anisotropy required by the seismotectonic model. This model is also supported by the high resolution tomographic results of the more shallow structures in the Pollina area, and by the study of two recent minor seismic sequences affecting the northern Sicilian sector (2010-2012) in the Caprileone area (Messina) and in the Isola delle Femmine offshore (west of Palermo). In this last sector high resolution morphobatimetric (multibeam) data highlight the presence of very young morphological features related to the ENE-WSW and NNW-SSE trending structural systems, probably responsible of the recent events

Multidisciplinary geophysical investigations have been carried out in a small area of the Greek archaeological site of Kamarina, in southern Sicily, in order to support some hypotheses, derived from historical and archaeological bases. After an aerial photographic and thermographic survey, a small area near to the Agora has been considered for magnetometric and GPR investigations. Obtained results show a good correlation and allow to highlight some structures oriented in agreement with the uncovered remains. The use of integrated geophysical techniques allowed a more robust interpretation of the detected anomalies in order to better address the choices for new excavations

635 gPR AND MAgNETIC SuRvEy AT ThE KAMARINA ARChAEOLOgICAL SITE (SICILy, ITALy) SuPPORTED by AERIAL PhOTOgRAPhIC AND ThERMOgRAPhIC DATA R. Martorana1,2, P. Capizzi1, A. D’Alessandro2, A. Pisciotta3, S. Scudero2 1 Dip. di Scienze della Terra e del Mare, Università degli Studi di Palermo, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia, Centro Nazionale Terremoti, Italy 3 Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Italy

3D Ultrasonic Tomography for non-destructive test and for diagnostic study works of art is a rather established methodology. This method allow us to locate, within the volume of work of art, areas of structural non homogeneities, areas of decay, fracture or damaged. This work wants to present some tests carried out to optimize these parameters in order to obtain a better anomaly image resolution for the case history presented. The optimization of these parameters allows locating structural non homogeneity areas, fractures or damages, within the volume, according to shape and type of the investigated anomalies

Introduction. The use of HVSR technique allows in many cases (Bonnefoy-Claudet et al., 2006) to obtain detailed reconstruction of the roof of the seismic bedrock (Di Stefano et al., 2014) and to identify areas with similar seismic behaviour. Theoretical considerations (Nakamura, 1989) and experimental tests showed that amplification of horizontal motions between bottom and top of a sedimentary cover is well related to the ratio between the spectra of the horizontal and vertical components of the ground velocity (Nakamura, 2000). This ratio is a measure of ellipticity of Rayleigh wave polarization, overlooking Love and body waves contribution. Assuming that subsoil can be represented as a stack of homogeneous horizontal layers and imposing some geometric and/or physical constraints it is possible to estimate the parameters of the shear wave velocity model (Fäh et al., 2003; Parolai et al., 2000). The integration of data related to HVSR and active techniques based on the analysis of s...

A systematic comparison is presented between some 2D resistivity models and their images by the inversion of synthetic datasets relating to three different arrays, suitable for multichannel data acquisitions (dipole-dipole (DD), Wenner-Schlumberger (WS) and multiple gradient (MG)). The goal is to study how the measurement errors affects the resolution of the tomographic models and the ability to retrieve correct information on buried targets. We considered different data acquisition patterns, gradually increasing the complexity of the combinations of potential spacing and dipolar distance. To this end we increased the number of current dipoles to obtain approximately the same amount of measures, increasing the investigation time. Results from noise-free and noisy data are discussed and compared with those from field data. The results show that: the quality of the inversion models, for a fixed noise level, depends significantly on the data acquisition pattern; the information recovery and the resolution, being equal the number of measurements, is overall better for WS and worse for DD; the decrease of sensitivity with depth is lower for particular acquisition patterns that allow to better resolve deeper targets; the MG array can be preferred because it provides comparable results, using a smaller number of current electrodes.

Abstract In the last few years, the geophysical methods of seismic refraction tomography (SRT) and electrical resistivity tomography (ERT) are among the most used geophysical techniques for the reconstruction of subsoil geometries, for the investigation of underground cavities and also for the archaeological prospecting. However, the main disadvantage of each geophysical method is the difficulty of final interpretation of the data. In order to eliminate artifacts and generally improve the reliability and accuracy of geophysical interpretation, it is useful to perform a joint approach of different geophysical methods, also introducing the a priori information. In this work, it is shown the integrated study of seismic refraction tomography and electrical resistivity tomography techniques, the two geophysical methods are tested on both synthetic and real data and the integration of data is useful in detecting buried cavities and also evaluate their geometric characteristics. Likelihood parameters has been defined and tested, in order to help recognizing voids from other lithological structures. Finally, a statistical approach based on cluster analysis of the P-wave velocity, the density of the seismic rays and the electrical resistivity of the synthetic and experimental models was used. Multi-space cluster distribution maps were built, allowing to better define and interpret the anomalies of the subsoil.

In recent years, a detailed archeoseismological investigation has been carried out in the necropolis of Abakainon in order to identify traces of an ancient earthquake. Although the identification of seismic damage was undoubtedly attributed to the 1st century AD earthquake, it was hypothesised that the level of damaging observed in the necropolis, as well as the counter slope tilting of the tomb basements may have also caused by a seismo-induced landslide, which produced locally an amplification of the seismic shaking. In order to identify the landslide, on which the Greek site lies, detailed geomorphological and geophysical surveys have been carried out. The research was directed to the acquisition of deep geological data for the reconstruction of slope process and the thickness of mobilised materials. The applied geophysical techniques included Seismic Refraction Tomography (SRT), Electrical Resistivity Tomography (ERT), microtremor analysis (HVSR). The surveys were performed in order to delineate the sliding surface and to assess approximatively the thickness of mobilised materials. The results coming from geomorphological data combined with and geophysical surveys confirm the presence of different overlapped landslides in the studied area.

The georadar method was used to try to find some anthropic structures in a large square inside the Carabinieri barracks in the former military complex of San Giacomo degli Spagnoli in Palermo (Italy). These investigations are part of a broader context of a study of the entire area. The purpose of the investigations is to try to understand if under the ground there are the remains of an ancient horse passage that connected the Royal Palace of Palermo with the sea gate of the city. Furthermore, in the Middle Ages, on the site of the present square, there were most likely two churches, which no longer exist, as evidenced by numerous historical testimonies. One of the two, San Giacomo la Mazara, is known to have was placed right in front of the church of San Paolo, the subject of previous investigations. The investigations carried out on the main square of the military district allowed us to reconstruct a 3D georadar model in which numerous anomalies are highlighted. Some superficial an...

The selection of the elementary analysis windows in continuous noise recordings for optimal estimation of the mean horizontal‐to‐vertical spectral ratio (HVSR) curve is generally performed by visual inspection of HVSR curves considered as functions of time. Starting from full‐length records, HVSR curves are determined in consecutive time windows of appropriate lengths. Time windows with HVSR curves that are anomalous on the basis of a simple visual inspection are generally ignored in the computation of the average HVSR curve. It is often very difficult to optimize the selection of time windows to be used for the calculation of the HVSR curve representative of a site. The use of nonobjective selection criteria produces results which depend on personal opinions of the operator and for which reliability cannot be assessed with quantitative parameters. We implemented an automatic procedure, based on cluster analysis, for the determination of the optimal window subset for the computation of the average HVSR curve. The procedure is based on the application of the agglomerative hierarchical clustering, using a measure of proximity of the standard correlation between HVSR curves and, as a rule for merging clusters, the average linking criterion. The procedure has been applied to 814 measures of seismic noise, carried out for the first‐level microzonation of 20 municipalities of Eastern Sicily characterized by high seismic hazard. A critical comparison of the results obtained by the clustering procedure implemented with those previously obtained by processing the same recordings with a technique based on the visual comparison of the spectral ratios of all the analysis windows has shown that the automatic clustering procedure seems to be capable of achieving a better partitioning of a set of HVSR curves and thus provides effective help in the process of distinguishing between peaks mainly linked to the site effects and others mainly related to the source effects.

The conservation, the exploration and the management of artistic and cultural heritage are of paramount importance for Italy. Many efforts are daily made to conserve, explore and manage the art crafts, the historical buildings, the museums, the archaeological sites and all the " objects " that

Detection of the Earth’s magnetic field anomalies is the basis of many types of studies in the field of earth sciences and archaeology. These surveys require different ways to carry out the measures but they have in common that they can be very tiring or expensive. There are now several lightweight commercially available magnetic sensors that allow light-UAVs to be equipped to perform airborne measurements for a wide range of scenarios. In this work, the realization and functioning of an airborne magnetometer prototype were presented and discussed. Tests and measures for the validation of the experimental setup for some applications were reported. The flight sessions, appropriately programmed for different types of measurements, made it possible to evaluate the performance of this detection methodology, highlighting the advantages and drawbacks or limitations and future developments. From the results obtained it was possible to verify that the measurement system is capable of carryi...

Archaeoseismology can provide a useful chronological tool for constraining earthquakes and documenting significant evidence that would otherwise be lost. In this paper, we report a case of surface faulting on ancient man-made structures belonging to the archaeological site of Santa Venera al Pozzo situated along the eastern flank of Mt. Etna volcano in eastern Sicily (southern Italy), which is affected by well-developed tectonic faults. Geological surveys highlight a set of fractures affecting the archaeological ruins, suggesting the occurrence of a capable fault zone across the area. An integrated geophysical survey was carried out in order to identify the main subsurface tectonic discontinuity ascribable to the fault zone. The information derived from different geophysical techniques, such as electrical resistivity tomography, seismic refraction tomography, ground-penetrating radar, and magnetic surveys allowed us to infer that the fractures observed at the surface could have been produced by coseismic rupture. They are conceivably linked to a strong earthquake that probably occurred in the Roman period, around mid-end of the third-century AD; time constraints are inferred through the dating of buildings of the archaeological site.

Kamarina, located in southern Sicily (Italy), was an important Greek colony since its foundation in the sixth century BC. Archaeological excavations, carried out since the twentieth century, uncovered only limited portions of the site so far. Despite the importance of the Greek colony, the presence of remarkable buildings that archaeologists expected to bring to light has not found fully correspondence in the archaeological excavations. Consequently, the integrated geophysical prospection carried out in the study area is aimed to support and address the future archaeological investigations. After the photographic and thermographic survey obtained by an unmanned aerial vehicle, we performed a systematic survey through ground magnetic and GPR methods over an area of 6200 m 2. The acquisition procedures have been optimized in order to get the best results combining high resolution and elevated speed of acquisition. The results derived from the three geophysical techniques have been conveniently combined by means of a cluster analysis, allowing us to clearly identify a series of buried archaeological features. Because of their geometrical characteristics, often in good agreement with the spatial arrangement of the archaeological remains at the surface , these buried archaeological features can be interpreted as roads, walls, or buildings foundations in which the various construction phases of the city can be clearly recognized. The integrated approach has proven to be essential for a robust interpretation of the archae-ogeophysical investigation. Keywords Archaeogeophysics · Ground magnetic survey · GPR · UAV thermography · Cluster analysis · Kamarina · Sicily

Structural analysis of marble statues, carried out by non-invasive and in situ methods, is crucial to define the state of conservation of the artworks and to identify the deterioration phenomena that can affect them. In this work, we combined in situ non-destructive techniques, ultrasonic tomography (US), ultraviolet-induced visible fluorescence (UV-IF) and X-ray fluorescence (XRF) to study the bass-relief 'Madonna con Bambino' (Gorizia, Italy). The US revealed the presence of some metallic pivots, associated with areas of high sound velocity; moreover, a more degraded area has been identified in the lower part of the bass-relief. The acquired UV-IF image confirmed the presence of surface degradation, allowing a preliminary evaluation of the extension of a fracture, from surface to bulk. In addition, the different materials (both original and/or integrations) that compose the studied surface have been identified. The XRF has contributed to define the nature of the inorganic materials applied during undocumented previous restoration works on the surface as filler for lacunae.

The Northern Sicily and its Tyrrhenian off-shore are part of the Maghrebian chain, whose the architecture is the result of a multiple-phase tectonic history from Late Oligocene-Early Miocene to Present. The main structural features, occurring from regional to outcrop scale, are represented by NW-SE to W–E striking right-lateral faults and by N–S to NE-SW striking left-lateral faults, both responsible of uplift and lowering respectively of restraining or releasing zones. With the aim to better define the seismotectonic model of this area, we carried out an integrated research, by means structural, geophysical and statistical analyses, in some key areas, placed both in the onshore and in the offshore northern Sicily sectors. On the first one the brittle strain partitioning related to a right-lateral simple shear zone has been reconstructed, on the second one the structural setting has been inferred from morpho-bathymetric and geological maps of the Southern Tyrrhenian basin.

Because of its high seismic hazard the urban area of Oliveri has been subject of first level seismic microzonation. The town develops on a large coastal plain made of mixed fluvial/marine sediments, overlapping a complexly deformed substrate. In order to identify points on the area probably suffering relevant site effects and define a preliminary <i>V</i><sub>s</sub> subsurface model for the first level of microzonation, we performed 23 HVSR measurements. A clustering technique of continuous signals has been used to optimize the calculation of the HVSR curves. 42 reliable peaks of the <i>H/V</i> spectra in the frequency range 0.6–10 Hz have been identified. A second clustering technique has been applied to the set of 42 vectors, containing Cartesian coordinates, central frequency and amplitude of each peak to identify subsets which can be attributed to continuous spatial phenomena. The algorithm has identified three main clusters that cover signif...

Geophysical project has been conceived to get information on topics connected to the following problems: − Deep failures in the southern part of the “Ambulatory of the Big Game Hunt”; − Presence of underground voids connected to the failure areas; − Reconstruction of natural and artificial (both ancient and recent) buried waterlines; − Recognition of the age and relative extension of various masonry walls and their geophysical characterization

This paper presents a new non-invasive methodology useful to univocally identify 3D rigid and elastic objects, particularly lapideous and ceramic artefacts and stones, by means of retrieving their capabilities to vibrate when stressed by artificial sources. A new instrument has been arranged to apply the methodology to large pieces in situ; it is provided with 16 piezotite sensors (Murata pads, Piezotite non-resonant type, 6CC-10-3R9-1000), while another instrument is being prepared to test the vibrations of small stones, using a triggered tweeter as source and a small laser remote sensor to measure the vibrations of the stones.

An integrated geophysical survey has been conducted at the Tarragona s Cathedral (Catalonia, NE Spain) with the aim to detect the existence of archaeological remains of the Roman s temple devoted to August. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most famous temple of Spain (12th century) evolving from Romanesque to Gothic styles. A project including electrical resistivity tomography (ERT), ground probing radar (GPR) and frequency domain electromagnetics (FDEM) has been planned over one year and conducted during a week of intensive field survey. From all the methods applied, both ERT and GPR have provided some detailed information on subsoil structures. The ERT method has been applied with different techniques and arrays, ranging from standard Wenner-Schlumberger 2D sections to full 3D electrical imaging using the MYG array. Electrical resistivity data have been recorded extensively ...

A geophysical survey carried out with several prospecting methods has allowed the evaluation of the limits of interpretation of each methodology and the optimization of the synthesis models.The overall project involves the execution of geotechnical, geophysical and geostructural measurements to investigate the causes that triggered the landslide that affects the slope on which it is founded the Cathedral of Agrigento. From the interpretation of the geophysical measurements and the integration of borehole data, a 3D model of the subsoil has been sketched for the side of the hill interested by the landslide. This allowed to detect and to map alternations of clay, silt and sand deposits such as biocalcarenite levels and blocks.

Identification of artworks is mainly based on a few characteristics which can be observed using non-invasive tools (sight, touch, simple instruments), the investigated properties being geometry, weight, colours, texture, etc. Nowa-days, technology allows reproducing all these characteristics to such an extent that even expert conservators can be de-ceived: in particular at the present time even the geometry of an artwork can be easily reproduced with the help of laser scanner analysis and with a rapid prototyping machine or a computer numerical control (CNC) milling machine. We pro-pose a new tool, the Sonic Imprint, producing a code capable of identifying a rigid artefact from its vibrational resonance frequencies beyond doubt. In fact the vibration modes of an artefact strongly depend on the spatial distributions of its den-sity and elastic parameters, as well as on its internal defects, definable in terms of abrupt changes of elastic properties in a small portion of the object. T...