We present in detail the preliminary results of a 3-D high-resolution seismic dataset acquired at Pantano di San Gregorio Magno (SA) across a surface scarp caused by the Ms 6.9, 1980 Irpinia earthquake, i.e., the 4th largest Italian earthquake of last century (Pantosti & Valensise, 1990). Some previous successful attempts of 2-D seismic imaging performed by Bruno et al. (2010) in the same area, clearly demonstrate that the near-surface throw of the Irpinia Fault in this area is modest and, therefore, subsurface constraints may be complementary with paleoseismology and classical analysis of short-term morpho-tectonic indicators (e.g., Pantosti et al., 1993; Pantosti &Valensise, 1990) for active fault detection and characterization. The seismic acquisition, made in collaboration with INGV and CNR, is the key part of the scientific project TESIRA (TEst Site IRpinia fAult), funded in 2021 by the University of Naples "Federico II". The project aims at acquiring multidisciplinary geophysical data and to achieve, through the integration of this multivariate dataset, an accurate 3-D imaging of the shallow structure of the fault zone and to understand the link between the shallow faulting and the petrophysical changes, which affect rock permeability and surface degassing. A microgravimetric and a 3-D Electrical Resistivity survey have been already acquired between September 2021 and January 2022. The gravity measurements were carried out using a Scintrex CG-5 Autograv gravimeter, with a resolution of 1 ?Gal. 3-D electric data were acquired using 216 nodes, with both Wenner-Schlumberger and Dipole-Dipole configuration. The surveyed area is 240x230 m2. The 3-D seismic data were acquired in July 2022, using two overlapping arrays with a dense geophone distribution: 5 m inline spacing and 10 m cross-line spacing. The first array being made of 12 lines for a total of 504 receivers, the second array consisting of 11 lines, with 525 receivers. The two arrays overlap in the central part (5 profiles). This device setup investigated at high resolution an area of about four hectares, with a total of 18 NNE-SSW, profiles, and 789 geophone positions and a total number of 1,115 vibrating points acquired with a high-resolution vibratory source. The preliminary results will consist of a 3-D tomography illuminating the first 50 m of the investigated area and a preliminary stack. Trace editing, in particular first arrival picking, is particularly challenging, due to the larger numbers of waveforms to be picked (more than 550,000) and the use of a vibratory source which generates artificial events before the first arrivals. To facilitate the picking, we use and discuss the advantages and the limits of a machine learning algorithm (i.e., neural networks) for automatic event picking.

The central-eastern sector of the Phlegraean Fields caldera, southern Italy, is one of the most intensely studied and monitored volcanic active area of the word. This area reveals typical characters of a high- enthalpy geothermal systems. However, recently the presence of two different geothermal reservoirs has been outlined: one located in the central sector dominated by highly active vapours generated by episodic arrival of CO2-rich magmatic fluids and the other one located in the eastern sector (Agnano zone) characterized by a shallow (400-500 m b.s.l.) still hot reservoir, heated by the upward circulation of deep no magmatic hot vapor. In this study we present preliminary results deriving from the integration of different geophysical surveys carried out in the Agnano plain area, in the frame of the GEOGRID research project. We acquired high-resolution gravity data along two parallel profiles and we investigated the depth, shape and density contrast of the subsurface structures by the CompactDEXP (CDEXP) method, a multiscale iterative imaging technique based on the DEXP method. The resulting density models, together with DC resistivity and stratigraphic data, outlines the presence of a complex morphology of the Agnano subsoil characterized by a horst-graben structure. The importance of the structural lines identified by geophysical data, is also confirmed by the alignment of correlate outcropping thermal waters.

In coastal alluvial plains, the variability of sedimentary inputs, tectonic and eustatism causes a complex subsurface geology which influences the position of fresh/saltwater interface. Furthermore, in these areas densely populated, the over-pumping of freshwater, coupled with the climate change events, promotes the landward migration of freshwater/saltwater boundary. This research illustrates the ability of geophysical tools to recognize the presence of salt/brackish water at Volturno Coastal Plain, Southern Italy. This area is characterized by a peculiar geological setting, due to the proximity at Somma-Vesuvio and Campi Flegrei volcanic areas, which profoundly influences the circulation of groundwater. The subsurface is mainly characterized by: (i) two denser layers located at - 10 m and - 20 m depth which in part prevents the vertical migration of groundwater, (ii) facies heteropy that facilitates the hydraulic connection between the different geological bodies, (iii) a discontinuous Campanian Ignimbrite deposits which favor the hydraulic connection between deeper and shallower aquifers. In this geological framework, 2D-ERT and 3D-ERT integrated with Downhole, Multichannel Analysis of Surface Waves and boreholes made possible to recognize the presence of two main zones with salt and brackish waters, respectively. The first zone, characterized by very low resistivity (<= 1 ?m) typical of salt water, stretches 1.5 km inland from the coast. The second zone, with a resistivity between 2 and 5 ?m typical of brackish water, continues for other 3 km inland. This knowledge is useful for the engagement of all stakeholders (farmers, ranchers and policy makers) in the sustainable use of fresh water and for making water management plan operational tools.

The development of geophysical exploration and techniques have proven to be of great help in identifying and classifying buried surfaces and for planning future excavation strategies. The purpose of this work is to detect the presence of buried structures (walls, floors, etc.) in unexplored areas of the Villa of St. Pietro ad Muricentum (Montebuono, Italy) and the Villa of Collesecco (Cottanello, Italy). Both areas were investigated with the Ground Penetrating Radar (GPR). The preliminary results show anomalies a few meters deep attributable to buried archaeological structures. These anomalies seem to be attributable, due to their shape and dimensions, to the presence of wall structures. Moreover, the maps obtained from the planimetric representation (time slices) of the Georadar reflections made it possible to follow the development, as the depth increased, of these structures and to reconstruct their reciprocal geometric correlation. This provides an overall view of the structures under investigation and provide useful guidance to archaeologists for the planning of excavation investigations.

In the search for bodies of archaeological interest at shallow depths, geophysical methods can provide useful indications. The aim of the present work, carried out in collaboration with the Archaeological Park of Cerveteri and Tarquinia, was to detect the presence of tombs/graves and/or buried structures in an unexplored area of Banditaccia Necropolis (Cerveteri and Tarquinia Archaeological Park), one of the largest ancient necropolis in the entire Mediterranean area. In the investigated area, two different non-destructive geophysical techniques have been employed: Ground-Penetrating Radar and gradiometry. The results made it possible to identify anomalies referable to probable structures of archaeological interest buried at a depth of several meters and probably attributable to tombs/graves. These geophysical results will preparatory to set up an archaeological excavation.

Aqua Virgo is the oldest Roman aqueduct still functioning in the city of Rome. It has never stopped working and still today it supplies some of the most famous fountains of the capital. The aqueduct was inaugurated in 19 B.C. and presents an almost entirely subterranean route. Geophysical measurements were undertaken with the aims to acquire further data about the water intake system of Aqua Virgo in Salone. The ancient aqueduct did not catch the water only from one single source but from a complex of springs and feeder channels located in the area. This project intents to bring light on the possible connections between the main underground specus of Aqua Virgo and its tributary channels, many of which are still unknown. The objectives are detecting and localising the underground feeder channels referring to the existing cartography of the area and to the airshafts visible on the surface. Once the conduits have been recorded using geophysical prospections, the further aim is to understand their dimensions, their constructive features, and their depth from the surface.

Nell'ambito delle attività di ricerca del progetto "TESIRA", in cui partecipano il Dipartimento di Scienze della Terra dell'Ambiente e delle Risorse (DISTAR) dell'Università degli Studi di Napoli "Federico II" (Responsabile scientifico: Prof. Pier Paolo Bruno), l'Istituto di Scienze del Patrimonio Culturale del Consiglio Nazionale delle Ricerche CNR - ISPC e l'Istituto Nazionale di Geofisica e Vulcanologia sede di Roma (INGV), il gruppo di geofisica di Napoli dell'ISPC, coordinato dal dott. Vincenzo Di Fiore, ha condotto nell'area test del comune di San Gregorio Magno (SA) un'indagine di tomografia geoelettrica 3D, per l'individuazione e la ricostruzione tridimensionale delle strutture presenti nel sottosuolo connesse con la faglia di SGM. In particolare, nell'area è presente una faglia attiva (Irpinia, 1980) con una lunghezza di circa 4 km e con uno spessore dello strato sismogenetico di 8-10 km (INGV, 1999). Ricordiamo che il terremoto dell'Irpinia del 1980 aveva magnitudo Ricther di 6.9 e provocò 3000 vittime.

Con riferimento al progetto HHU-AQ.VIRG.S. con responsabile la Dott.ssa Maria Elisa Amadasi (call E-RIHS di accesso a MOLAB del 02/12/2021 chiusa il 28/02/2022 e con notifica per l'accesso alla user del 06/06/2022) si riportano di seguito i risultati ottenuti dall'indagine geofisica. Le indagini sono state realizzate mediante metodologie non distruttive con apparecchiature in dotazione al Laboratorio di Geofisica Applicata ai Beni Archeologici e Monumentali della sede del CNR-ISPC di Napoli. Allo scopo di individuare strutture di interesse archeologico eventualmente presenti all'interno dell'area indagata, è stata impiegata la metodologia di indagine geofisica denominata georadar. E' stato inoltre utilizzato una stazione GPS (differenziale) per la georeferenzazione dei risultati. E' stato impiegato il georesistivimetro Syscal Pro con 10 canali attivi e 96 elettrodi e dispositivo Wenner-Schlumberger. Le indagini geofisiche sono state effettuate in data 18/04/2023, sotto il coordinamento del Dott. Vincenzo Di Fiore. Le indagini sul campo sono state realizzate dal Dott. Michele Punzo. Le elaborazioni dei dati geofisici sono a cura del Dr. Vincenzo Di Fiore e la Dott.ssa Daniela Tarallo.

The scientific project TESIRA (TEst Site IRpinia fAult), funded in 2021 by the University of Naples "Federico II", aims at acquiring multidisciplinary geophysical data above an active fault in an intramontane basin of the Southern Apennines and to achieve, through the integration of this multivariate dataset, an accurate 3D geophysical imaging of the shallow structure of the fault zone in order to understand the link between shallow faulting and petrophysical changes, which affect rock permeability and surface degassing. The target structure is the southern branch of the Irpinia Fault, one of the structures with highest seismogenic potential in the Mediterranean region, causing the 4th Italian earthquake of last century (1980, Ms=6.9, Pantosti & Valensise, 1990) and generating a modest surface throw at Pantano San Gregorio Magno (Salerno). A microgravimetric survey and a 3D and 2D Electrical Resistivity measurements survey were acquired between September 2021 and January 2022. 3D seismic data were acquired in July 2022, using two overlapping arrays with a dense geophone distribution covering an area of about four hectares, with a detail of 2.5x2.5m. Moreover, four 2D seismic profiles intersect the 3D volume. An aeromagnetic survey, an extension of the gravimetric survey and a sampling of the CO2 surface degassing will be completed within this year. We will show the preliminary results of the individual surveys. Later, the different geophysical and geochemical measurements will be integrated using cooperative inversion and machine learning techniques. We hope that this multidisciplinary approach will provide a more comprehensive understanding of the interaction between surface faulting and basin development in this key area of the Southern Apennines.

This paper evaluates the amplification factors at different locations of a tuff cliff subjected to seismic loading. We present a 1D and 2D modelling of a cliff located in the Sorrento Peninsula, a major Quaternary morpho-structural unit of the western flank of Southern Apennines. The geometry of our model is represented by a tuff cliff of 30 m height, with sand deposits at its base, covered by a 7-m-thick volcanoclastic layer. The geotechnical and geophysical parameters used for the analysis have been estimated via field measurements and laboratory tests. We selected seven scaled seismic events as input motions for the analysis, and the linear equivalent assumption was used in both 1D and 2D modelling. The general trend showed that in the cliff edge area, the amplification factor reaches a maximum value of 10 with a period of 0.11 s, while in other areas, its value decreases down to 2.90 seaside and 4.0 landside. The comparison of the 1D and 2D modelling highlights the importance of the topographic effects connected with a cliff. The average amplification factors (AF) for the 1D and the 2D models, have been computed within different time ranges, consistent with the ones adopted in the Italian microzonation studies (0.1-0.5 s, 0.4-0.8 s, 0.7-1.1 s).

Con riferimento al progetto HHU-AQ.VIRG.S. con responsabile la Dott.ssa Maria Elisa Amadasi (call E-RIHS di accesso a MOLAB del 02/12/2021 chiusa il 28/02/2022 e con notifica per l'accessa alla user del 06/06/2022) si riportano di seguito i risultati ottenuti dall'indagine geofisica. Le indagini sono state realizzate mediante metodologie non distruttive con apparecchiature in dotazione al Laboratorio di Geofisica Applicata ai Beni Archeologici e Monumentali della sede del CNR-ISPC di Napoli. Allo scopo di individuare strutture di interesse archeologico eventualmente presenti all'interno dell'area indagata, è stata impiegata la metodologia di indagine geofisica denominata georadar. E' stato inoltre utilizzato una stazione GPS (differenziale) per la georeferenzazione dei risultati. E' stato impiegato il GPR Impulsato Sir 3000 dotato di antenna da 270MHz. Le indagini geofisiche sono state effettuate in data 06/09/2022, sotto il coordinamento del Dott. Vincenzo Di Fiore. Le indagini sul campo sono state realizzate dal Dr Vincenzo Di Fiore, dalla Dott.ssa Daniela Tarallo, dal Dott. Michele Punzo. Le elaborazioni dei dati geofisici sono a cura del Dr. Giovanni Leucci.

With reference to the "Diagnostics for Conservation at Müstair Monastery" project (DIACOMM, mol_1) with Dr. Patrick Cassitti in charge (IPERION HS 2nd call for access to MOLAB of 01/02/2021 closed on 30/06/2021 and with notification for access to the user of 10/09/2021) are reported by followed the results obtained from the geophysical survey. To study the state the state of conservation of the fresco inside the monastery of San Giovanni in Mustair, geophysical surveys with ground-penetrating radar (GPR) were undertaken in September 2022. The surveyed area is shown in Fig. 1. The GPR data weed using the Sir 3000 georadar system (GSSI) with the 2GHz, and 900MHz antennae along grids with parallel profiles set 0.1 m apart for the 2GHz and 0.25m apart for 900MHz. Data were acquired by the Laboratory of Geophysics of the Institute of Heritage Science (National Research Council) team. The team was composed by Dr Vincenzo Di Fiore (ISPC Napoli), Dr Ivan Ferrari (ISPC Lecce), Dr Daniela Tarallo (ISPC Napoli), and Dr Michele Punzo (ISPC Napoli). The measurements were carried out on the 13 and 14 September 2022.

Il Real Sito di Carditello, situato nella provincia di Caserta in Campania, è il principale sito di sperimentazione del progetto di ricerca IDEHA (Innovation for Data Elaboration in Heritage Areas, PON Ricerca & Innovazione 2014-2020). Sono state realizzate acquisizioni geofisiche a scopo diagnostico sulle strutture della palazzina reale presso la Tenuta di Carditello. In particolare, è stato eseguito un rilievo GPR (Ground Penetrating Radar) utilizzando un'antenna ad alta frequenza (900 MHz) lungo le murature perimetrali della facciata principale, dell'androne e sui solai in alcune stanze al piano terra, primo piano e sottotetto. E' stato eseguito inoltre, un rilievo GPR con antenna a media frequenza (270 MHz) su alcune parti del perimetro della facciata esterna. Ad integrazione delle indagini GPR è stato eseguito un rilievo di tomografia di resistività elettrica (ERT) in configurazione 3D su parte della facciata esterna dell'edificio.

Nell'ambito del Progetto GEOGRID sono sate relizzate delle indagini geofisiche nella conca di Agnano in particolare nell'ippodromo di Agnano. Sul sito in esame, dove sono già state precedentemente eseguite indagini di tipo geoelettrico, di sismica attiva e di gravimetria, sono state eseguite misure di rumore ambientale, quest'ultime oggetto di tale rapporto, mediante geofoni triassiali da 4.5 Hz. I sensori sono stati posizionati sul terreno secondo tre stendimenti lineari, al fine di ottenere nuovi elementi sull'assetto stratigrafico e strutturale dell'area in esame.

To characterize the shallow subsurface of the Holy Church of Resurrection in Jerusalem, geophysical surveys with ground-penetrating radar (GPR) were undertaken at the end of October 2021. The GPR data were acquired using the Sir 3000 georadar system (GSSI) with the 270MHz, and 900MHz antennae along grids with parallel profiles set 0.4 m apart for the 270MHz and 0.2m apart for 900MHz. Data were acquired by the Laboratory of Geophysics of the Institute of Heritage Science (National Research Council) team. The team was composed by Dr Vincenzo Di Fiore (ISPC Napoli), Dr Ivan Ferrari (ISPC Lecce) and Dr Michele Punzo (ISPC Napoli). The measurements were carried out on the 22, 23 and 24 October 2021

This paper presents the results of a geophysical investigation aimed to illustrate the architecture of the shallow stratigraphic horizons across an area believed to be crossed by a NW-SE trending trascurrent fault called the Lamezia Terme-Catanzaro Fault. In spite of the available information on fault segments and tectonic activity associated with faulting, the local scale fault characteristics are currently poorly known and the surface displacements are difficult to detect in a such a densely populated area. A traditional integrated geophysical exploration method was proposed as an effective solution to assist in the location of structures in the subsurface where surface geological and morphological evidence is inconclusive in terms of defining the location and the potential of the local seismogenic sources, responsible for recurrent catastrophic earthquakes. Two active High Resolution (HR) seismic reflection/refraction profiles were acquired using an array of vertical geophones with a Swept Impact Seismic Source (VibSist-500) in order to obtain seismic imaging of the subsurface of the study area. Additionally, passive Microtremor Array Method (MAM), deep wells and commercial seismic profiles were used to better constrain the geological trend of deeper seismostrata. The integrated interpretation of both geophysical and geological data allowed to infer subsurface pictures of the investigated areas identifying the depth of the seismic bedrock and characterizing the buried morphology, enhancing lineaments with possible relevance to faults. Discontinuities in the main horizons in seismic sections indicate that faulting is present in a Pliocene unit and may extend to the shallow subsurface in Quaternary sediments. The results of this study can provide a basis for earthquake prevention and construction work and demonstrate the applicability of the seismic methods to explore buried hidden faults in the perspective of applications on studies of physical stratigraphy of syn-tectonic deposits.

Oggi nello studio di siti adibiti a discarica ed in particolar modo per quelli divenuti tali a seguito di azioni illecite, risulta di fondamentale importanza la comprensione preliminare dell'estensione e della morfologia dell'area interessata dall'accumulo di rifiuti così come delle interrelazioni tra gli stessi ed il territorio circostante ed, in particolare, nel rilascio di percolato e biogas. I metodi di seguito proposti, pur seguendo due approcci distinti, hanno il fine comune di consentire la necessaria consapevolezza per pianificare e gestire al meglio ogni successiva azione di indagine e caratterizzazione puntuale che altrimenti si rivelerebbe sicuramente dispendiosa e non sempre efficace. Questo articolo riporta due casi studio condotti dai partecipanti del gruppo di lavoro con l'intento di mostrare il vasto campo di applicazione delle metodologie geofisiche nel rilevamento e nell'indagine delle principali caratteristiche di una discarica di rifiuti solidi. La presenza di discariche, in cui al corpo rifiuti spesso si associano biogas e percolato, determinano importanti variazioni di alcuni parametri fisico-chimici, individuabili mediante l'utilizzo di tecniche non invasive di tipo geofisico. Lo scopo del presente lavoro è l'analisi delle potenzialità e dei limiti dell'integrazione di differenti metodi geofisici (tomografia elettrica di resistività, polarizzazione indotta, metodo magnetico e georadar) per la localizzazione di rifiuti interrati di diversa natura. Nel primo caso di studio elementi chiave di novità di questo approccio per la caratterizzazione e il monitoraggio dell'area di discarica sono la combinazione e l'integrazione di diversi approcci metodologici (geofisici e non), come l'uso parallelo e combinato di dati raccolti da satellite, aereo e in situ, che sono stati convalidati attraverso indagini geofisiche (metodi geoelettrici) e che hanno rivelato l'efficacia di questa strategia. La seconda parte di questo lavoro ha avuto lo scopo di verificare l'efficienza di antenne GPR (Ground Penetration Radar) a diversa frequenza (100 MHz - 270 MHz) e indagini magnetometriche gradiometriche in terreni di natura piroclastica dove sono stati interrati oggetti di varia natura e a diverse profondità. L'attività ha permesso di conseguire importanti informazioni sulla scelta della frequenza di utilizzo delle antenne GPR e tecniche magnetometriche in terreni piroclastici e sulla risposta che tale tecnica fornisce nell'identificazione di oggetti sepolti come fusti metallici e muretti in tufo.

Scopo del presente lavoro è verificare la risposta di antenne GPR (Ground Penetration Radar) a diversa frequenza (100 MHz - 270 MHz) in terreni di natura piroclastica dove sono stati interrati oggetti di varia natura (fusti metallici, muretti in tufo e tubi in PVC) e a diverse profondità (1m - 2m - 3m). Conoscendo la stratigrafia di massima del sottosuolo e la disposizione degli oggetti sepolti, sono stati ottenuti radargrammi 2D la cui analisi ed interpretazione hanno permesso di definire la risposta delle antenne GPR in termini di risoluzione e profondità. L'attività ha permesso di conseguire importanti informazioni sulla scelta della frequenza di utilizzo delle antenne GPR in terreni piroclastici e sulla risposta che tale tecnica fornisce nell'identificazione di oggetti sepolti come fusti metallici, muretti in tufo e tubi in PVC. Tali informazioni risultano essenziali qualora venga usata la tecnica GPR per rilevare la presenza di oggetti sepolti (metallici e non) a varie profondità.

Le metodologie e gli strumenti per la ricerca indiretta di siti contaminati hanno avuto negli ultimi anni un sostanziale sviluppo. In particolare, lo sviluppo di metodologie geofisiche, utilizzati in altri campi, permettono diraggiungere risultati molto importanti nella ricerca di discariche abusive sepolte. In questo lavoro, si descrivono tali approcci per rilevare e studiare le principali caratteristiche di siti contaminati ed in particolare da discarica occulte di rifiuti solidi. Attraverso l'integrazione di metodi geologici, geografici e geofisici, viene effettuata un'analisi multi-temporale dell'evoluzione morfologica delle aree di indagine utilizzando foto aeree e satellitari disponibili e riferite alle aree di studio. Successivamente, mediante la combinazione di indagini geofisiche da superficie del tipo geoelettrico, geomagnetico ed elettromagnetico, si arriva ad un modello geologico-geofisico del sottosuolo che ci permette di fare ipotesi più accurate. Un esempio di tale approccio è stato testato con successo per assistere la Procura di Salerno durante un'indagine specifica su una discarica illegale. Tutti i dati raccolti sul campo sono stati utilizzati sia per la ricostruzione multi-temporale della storia del sito, che per definire la geometria attuale della cava e la geologia del sito. Gli elementi chiave della novità di questo metodo sono la combinazione e l'integrazione di diversi approcci metodologici, come l'uso parallelo e combinato di dati satellitari, aerei e in situ, che sono stati validati in una vera indagine e che hanno dimostrato l'efficacia di questa strategia.

This paper attempts to provide a contribute to electric field monitoring on soil by Self-potential (SP) survey utilizing matrix determinant and eigenvalues. SP is connected to the electrical conductivity of soil that is an indirect measurement and correlates very well with several physical and chemical properties. The purpose of this method is to map the electrical potential to reveal one or several polarization mechanisms at play in the ground. In some cases, the self-potential signals are monitored with an electrodes network which provides the possibility to discriminate between various sources. Our study provides synthetic and experiment cases that carried out a semi-quantitative method to estimate the variation of the electric field vector in the soil starting from the measurement of the SP. The experimental case is referred to a site located in the Campania Region in southern Italy. SP measurements can be performed by array dipoles oriented N-S, E-W and vertical direction. In this way, we can define the contribution of the electric field in both time and spatial domain. Now, if we denote with V(t) the potential difference between two electrodes, for each dipole, we will have 3 values Vx(tn), Vy(tn) and Vz(tn) relative to the dipoles in the three directions. Assuming that the electric currents associated with the potentials are continuous or in any case at very low frequency, we can with good approximation assume that the resulting electric field associated with such currents is conservative. Remembering that in the case of a conservative field the electric field vector, we can be expressed as a gradient of the scalar potential V. The SP data were obtained using an Arduino acquisition system with internal voltmeter impedance of 10 MOhm and resolution of 0.1 mV. In order to provide reliable SP measurements, the impedance of the voltmeter needs to be substantially higher than the impedance of the soil between the electrodes because of the small bias current used to measure the voltage. The electric potentials were measured between each electrode and a reference electrode was connected by ground. The electrode consisted of 8 electrodes spaced 1m and arranged in a cross array which form 6 dipoles. The cross array was orientated in N-S and E-W direction. Because the SP depend on the electrical conductivity of the soil and therefore on the sources and the medium, any variation of the chemical-physical soil variation implies a variation of the SP. We calculated the determinant and the eigenvalues of the matrix whose columns consist of the components of the measured electric field and therefore, by such parameters it was possible to observe the variations of the electric field in the time domain.