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Troiano, Antonio
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Troiano, Antonio
Email
antonio.troiano@ingv.it
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staff
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Scopus Author ID
20735759300
Researcher ID
M-3347-2014
34 results
Now showing 1 - 10 of 34
- PublicationOpen AccessMonitoring active fumaroles through time-lapse electrical resistivity tomograms: an application to the Pisciarelli fumarolic field (Campi Flegrei, Italy)Volcanoes are usually monitored through observations of many physical and chemical phenomena. In the most dangerous cases, as the one of the Campi Flegrei caldera (Italy), great amount of data are collected, both in discrete or continuously, and regularly stored. However, how to transform such mass of data in a deeper understanding of the volcano dynamics is still an open question. Dissimilar information are in fact always hard to compare, but just integrating all the available knowledge hazardous events could be prevented in a reliable way. Fluids, as water and gasses mobilized in the subsoil by the heat induced by deep magmatic sources, are widely recognized as the first engine of similar occurrences and the volcanic gas emissions represent, together with the seismic activity, one of the most considered precursors. At the same time, the electrical geophysical methods are the most applied in order to detect and characterize the fluid patterns in the subsoil. So, the integration of geoelectrical and geochemical observations should represent one of the most pursued approach in volcanoes monitoring. On the contrary, standard way to compare such data has been not yet codified. The ERT tomograms capability to individuate that parts of the subsoil where gasses cumulate is well understood in literature. However, we look for indications about its proficiency in associating the electrical resistivity changes relative to these zones, once compared to the geochemical time series, to deep related contributes, distinguishing them from the seasonal ones. The electrical signature of the fluid patterns, reconstructed through a time-lapse ERT approach, could be of relevance to better characterize the volcanic phenomena and their origins. In this paper a first test of ERT and geochemical time series integration was performed to enhance the understanding of the Pisciarelli fumarolic field evolution, now the most active area in the whole Campi Flegrei caldera.
76 31 - PublicationOpen AccessA Coulomb stress model for induced seismicity distribution due to fluid injection and withdrawal in deep boreholes(2013)
; ; ; ; ; ; ; ; ; Fluid injection in and withdrawal from wells are basic procedures in mining activities and deep resources exploitation, such as oil and gas extraction, permeability enhancement for geothermal exploitation and waste fluid disposal. All of these activities have the potential to induce seismicity, as exemplified by the 2006 Basel earthquake (ML 3.4). Despite several decades of experience, the mechanisms of induced seismicity are not known in detail, which prevents effective risk assessment and/or mitigation. In this study, we provide an interpretation of induced seismicity based on computation of Coulomb stress changes that result from fluid injection/withdrawal at depth, mainly focused on the interpretation of induced seismicity due to stimulation of a geothermal reservoir. Seismicity is, theoretically, more likely where Coulomb stress changes are larger. For modeling purposes, we simulate the thermodynamic evolution of a system after fluid injection/withdrawal. The associated changes in pressure and temperature are subsequently considered as sources of incremental stress changes, which are then converted to Coulomb stress changes on favourably oriented faults, taking into account the background regional stress. Numerical results are applied to the water injection that was performed to create the fractured reservoir at the enhanced-geothermal-system site, Soultzsous-Forets (France). Our approach describes well the observed seismicity, and provides an explanation for the different behaviors of a system when fluids are injected or withdrawn.188 88 - PublicationRestrictedThe geothermal system of Ischia Island (southern Italy): Critical review and sustainability analysis of geothermal resource for electricity generation(2014)
; ; ; ; ; ; ; ; ; ; ; In this paper we analyze the main available data related to the geothermal system of Ischia Island, starting from the first geothermal exploration in 1939. Our aim is to define a conceptual model of the geothermal reservoir, according to geological, geochemical, geophysical and stratigraphic data. In recent times, the interest on geothermal exploitation for electricity generation in Italy is rapidly increasing and the Ischia Island is one of the main targets for future geothermal exploitation. Nowadays, one of the main economic resources of the island is the tourism, mainly driven by the famous thermal springs; so, it is crucial to study the possible interaction between geothermal exploitation and thermal spring activities. To this aim, we also analyze the possible disturbance on temperature and pressure in the shallow geothermal reservoir, due to the heat withdrawal for electric production related to small power plant size (1e5 MWe). Such analysis has been performed by using numerical simulations based on a well known thermofluid-dynamical code (TOUGH2!). Obtained results show that such geothermal exploitation generates a perturbation of temperature and pressure field which, however, is confined in a small vol- ume around the well. At shallow level (0e100 m) the exploitation does not produce any appreciable disturbance, and can be made compatible with thermal spring exploitation. Moreover, such results are crucial both for the evaluation of volcanological processes in the island and for the general assessment of geothermal resource sustainability.300 5 - PublicationOpen AccessAbout the shallow resistivity structure of Vesuvius volcano(2008-02)
; ; ; ; ; ; ; ; ;Troiano, A.; Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Napoli, Italy ;Petrillo, Z.; Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Napoli, Italy ;Di Giuseppe, M. G.; Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Napoli, Italy ;Balasco, M.; Istituto di Metodologie per l’Analisi Ambientale (IMAA, CNR), Tito Scalo (Pz), Italy ;Diaferia, I.; Dipartimento di Geologia e Geofisica, Università degli Studi di Bari, Italy ;Di Fiore, B.; Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Napoli, Italy ;Siniscalchi, A.; Dipartimento di Geologia e Geofisica, Università degli Studi di Bari, Italy ;Patella, D.; Dipartimento di Fisica, Università degli Studi di Napoli «Federico II», Napoli, Italy; ; ; ; ; ; ; Magnetotelluric (MT) soundings performed in the past in the volcanic area of Mt. Vesuvius by two independent research groups showed in the same places MT apparent resistivity curves with very similar shape, but statically shifted by one order of magnitude, at least. To try to resolve this ambiguity new controlled source audio-magnetotelluric (CSAMT) measurements have been carried out in the same MT sites. The interpretation of the CSAMT dataset, combined with that of two shallow dipole-dipole geoelectrical resistivity tomographies previously carried out in the area have allowed a reliable electrical structure to be recovered down to a few km of depth, which will next be used for a best constrained re-interpretation of the deep MT soundings.449 746 - PublicationOpen AccessMultidisciplinary studies of diffuse soil CO2 flux, gas permeability, self-potential, soil temperature highlight the structural architecture of Fondi di Baia craters (Campi Flegrei caldera, Italy)(2019)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; We present in this paper the results of a geophysical and geochemical survey of self potential, diffuse soil CO2 flux, soil temperature and gas permeability carried out in the Fondi di Baia craters on the western sector of Campi Flegrei caldera, one of the most hazardous active volcano in Italy. Work was aimed at highlighting the small-scale volcano-tectonic structures of this Holocene edifice and at evaluating its state of fracturing, in order to ascertain possible volcanic hazard for future vent reopening. The central sector of Campi Flegrei (Solfatara volcano-Pisciarelli) is indeed the one most affected by ground deformation and intense hightemperature fumarolic activity, nevertheless it cannot be ruled out a future vent opening along the western collapsed margin of the caldera, where Fondi di Baia craters are located. Our results show that the Fondi di Baia craters are characterized by a medium-high release of hydrothermal fluids through fractures that mimic the main volcano-tectonic structures of this portion of the caldera. Moreover, results indicate that, in case of a future volcanic reactivation, these previous structures could as well be possible paths for magma ascent. We provide a first estimate of the total flux of CO2 from Fondi di Baia diffuse degassing structure, quantified in 10.06 ± 1.07 t*d-1.548 103 - PublicationOpen AccessMagnetotelluric imaging of the resurgent caldera on the island of Ischia (southern Italy): inferences for its structure and activity(2017)
; ; ; ; ; The island of Ischia (located in the Bay of Naples, Italy) represents a peculiar case of a well-exposed caldera that has experienced a large (>800 m) and rapid resurgence, ac- companied by volcanic activity. What drives the resurgence of calderas is a crucial issue to investigate, because this process is associated with potential eruptions and high risk to people living within and around such large active volcanic systems. To improve the knowledge of volcano-tectonic processes af- fecting the caldera of Ischia, electromagnetic imaging of the structures associated with its resurgence was performed and integrated with available geological information. A magnetotelluric (MT) survey of the island was carried out along two main profiles through the central-western sector, providing an electrical resistivity map to a depth of 3 km. These resistivity cross sections allowed us to identify the pres- ence of a very shallow magmatic intrusion, possibly a lacco- lith, at a depth of about 1 km, which was responsible for both the resurgence and the volcanic activity. Furthermore, the tec- tonic structures bordering the resurgent area and the occur- rence of a large thermal anomaly in the western sector of the caldera also provided a signature in the resistivity cross sec- tions, with the magma intrusion producing advection of hot fluids with high geothermal gradients (>150 °C km−1) in the southern and western sectors. All of these data are fundamen- tal for the assessment of the island’s volcano-tectonic dynam- ics and their associated hazards. The structure and activity of the island have been controlled by the process of resurgence associated with the arrival of new magma and the progressive intrusion of a laccolith at a shallow depth. The reactivation of such a shallow system may imply imminent eruption which would pose a major volcanic hazard.289 51 - PublicationOpen AccessA clustering approach to multiparameter geophysical data: different scale examples(2009-10-27)
; ; ; ; ; ; ; ;Di Giuseppe, M.G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Troiano, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Petrillo, Z.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Siniscalchi, A.; Dipartimento di Geologia e Geofisica, Università di Bari, Bari, Italy. ;Berrino, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Bruno, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Magrì, C.; Dipartimento di Geologia e Geofisica, Università di Bari, Bari, Italy.; ; ; ; ; ; ; ; ; ; ; ; ; ;Berrino, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;D'Errico, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Di Giuseppe, M.G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Petrillo, Z.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Ricciardi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Troiano, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; The correlation and integration of geophysical images obtained by several dataset of different nature, as seismic, magnetic, electric, electromagnetic and gravimetric, are usually limited to their qualitative observation and comparison229 164 - PublicationRestrictedExploitation of geothermal energy in active volcanic areas: A numerical modelling applied to high temperature Mofete geothermal field, at Campi Flegrei caldera (Southern Italy)(2016)
; ; ; ; ; ; ; ; ; ; ; ; ; The active volcanic area of Campi Flegrei represents one of the “hottest” sites of worldwide continental areas. Exploitation for geothermal energy of this volcano is of great interest, because temperatures>150 C occur at very shallow depth (0.5e1 km). Since present time, the exploitation of geothermal energy in Italy, for electric uses, has been confined to the Larderello and Mt. Amiata districts (Tuscany). With the recent introduction of new Italian regulations, which favor and incentivize inno- vative pilot power plants (5 MWe), many geothermal projects have been applied to volcanic districts of Southern Italy, providing a new important input to the development of zero-emission geothermal power plants. In this framework, we analyzed the sustainability of geothermal exploitation in the high tem- perature geothermal field of Mofete (Campi Flegrei caldera) in Southern Italy. By a review of all the available data of drillings performed at Mofete, from 1979 to 1987 by AGIP and ENEL companies, and using a numerical simulation (TOUGH2®), we evaluate the thermal and pressure perturbation of the reservoirs, and the possible induced seismicity, due to extraction and reinjection of fluids, at different depths and temperatures. The results are fundamental in planning a sustainable geothermal energy production in urbanized and high volcanic risk areas.534 8 - PublicationOpen AccessDeep Electrical Resistivity Tomography for a 3D picture of the most active sector of Campi Flegrei caldera(2019-10-22)
; ; ; ; ; ; ; ; ; The central sector of the Campi Flegrei volcano, including the Solfatara maar and Pisciarelli fumarole field, is currently the most active area of the caldera as regards seismicity and gaseous emissions and it plays a significant role in the ongoing unrest. However, a general volcano-tectonic reconstruction of the entire sector is still missing. This work aims to depict, for the first time, the architecture of the area through the application of deep Electrical Resistivity Tomography. We reconstructed a three-dimensional resistivity model for the entire sector. Results provide useful elements to understand the present state of the system and the possible evolution of the volcanic activity and shed solid bases for any attempt to develop physical-mathematical models investigating the ongoing phenomena.77 41 - PublicationOpen AccessA geophysical k-means cluster analysis of the Solfatara-Pisciarelli volcano-geothermal system, Campi Flegrei (Naples, Italy)(2018)
; ; ; ; ; ; ; ;; We present an application of the k-means cluster analysis technique to a trivariate geophysical parameter set dis- tributed over a 3 km thick and 1.2 km long section through the geothermally active Solfatara-Pisciarelli area of the Campi Flegrei caldera (Italy). The data set consists of resistivity, P-wave velocity and density parameters, ex- tracted from previously modeled univariate sections through the selected profile and mapped in a joint param- eter 3D space. Six compact and separated clusters have been identified. A subsequent linear regression statistics has allowed two distinct branches of clusters to be recognized, each represented in the joint parameter space by the equation of a plane. Each equation and its partial derivatives define the peculiar combinations among the used parameters. Once mapped back to the space domain, the final image has provided a grouping of the struc- tures in two superimposed blocks with an irregular interface located at 2 km mean depth. Based on drilling data, subsurface stratigraphy and recent seismic activity, the interface between the two blocks has been interpreted in terms of a substantial change in the rocks rheology inside the Solfatara-Pisciarelli volcano-geothermal system, namely the brittle-to-ductile transition.332 520