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De Natale, Giuseppe
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Preferred name
De Natale, Giuseppe
Email
giuseppe.denatale@ingv.it
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staff
ORCID
Scopus Author ID
7006560861
Researcher ID
M-6763-2016
102 results
Now showing 1 - 10 of 102
- PublicationRestrictedFluid injection in Enhanced Geothermal Systems: a study on the detectability of self-potential effects and on their correlation with induced seismicity(2017)
; ; ; ; ; ; ; ; ; ; ; We present a numerical modeling aimed at investigating nature and role of the self-potential (SP) anoma- lies induced by water injection in boreholes at the Soultz-sous-Forêts (SsF) hot dry rock enhanced geothermal field. The overpressure due to the fluid stimulation is considered as source of the streaming potential effects in rocks, responsible on their turn of the SP anomalies observed at the ground surface. The numerical simulations have been realized by a combined application of the TOUGH2 and Comsol Mul- tiphysics codes, which had already been successfully used to predict Coulomb stress changes in rocks induced by a fluid injection cycle. Two synthetic cases are investigated. At first, a simulated injection cycle in a single borehole has been modeled, consisting in the reconstruction of the overpressure and SP temporal and spatial evolutions induced by the hydraulic stimulation of the rock. The main result is that the front of the SP anomaly follows the overpressure front, with the time delay between the two fronts decreasing at increasing distance from the well. The second case takes into consideration a real injection experiment performed in 2003 at SsF, which has allowed to examine the induced seismicity. The simulated SP response to this real injection cycle shows that the SP temporal evolution is essentially a post-seismic effect. The conclusion from the simulations is that SP measurements can be used to localize the main features of the fluid flow into the reservoir.246 27 - PublicationOpen AccessContinuous in situ measurements of volcanic gases with a diode-laser-based spectrometer: CO2 and H2O concentration and soil degassing at Vulcano (Aeolian islands: Italy)(2007)
; ; ; ; ; ; ;De Rosa, M.; CNR, Istituto Nazionale di Ottica Applicata, Sezione di Napoli, I-80078 Pozzuoli (NA), Italy ;Gagliardi, G.; CNR, Istituto Nazionale di Ottica Applicata, Sezione di Napoli, I-80078 Pozzuoli (NA), Italy ;Rocco, A.; CNR, Istituto Nazionale di Ottica Applicata, Sezione di Napoli, I-80078 Pozzuoli (NA), Italy ;Somma, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Natale, P.; CNR, Istituto Nazionale di Ottica Applicata, Sezione di Napoli, I-80078 Pozzuoli (NA), Italy ;De Natale, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; We report on a continuous-measurement campaign carried out in Vulcano (Aeolian islands, Sicily), devoted to the simultaneous monitoring of CO2 and H2O concentrations. The measurements were performed with an absorption spectrometer based on a semiconductor laser source emitting around a 2-μm wavelength. The emitted radiation was selectively absorbed by two molecular ro-vibrational transitions specific of the investigated species. Data for CO2 and H2O concentrations, and CO2soil diffusive flux using an accumulation chamber configuration, were collected at several interesting sampling points on the island (Porto Levante beach- PLB, Fossa Grande Crater - FOG- and Valley of Palizzi, PAL). CO2/H2O values, measured on the ground, are very similar (around 0.019 (± 0.006)) and comparable to the previous discrete detected values of 0.213 (Fumarole F5 -La Fossa crater rim) and 0.012 (Fumarole VFS - Baia Levante beach) obtained during the 1977-1993 heating phase of the crater fumaroles. In this work much more homogeneous values are found in different points of the three sites investigated. The field work, although carried out in a limited time window (25th-28th August 2004), pointed out the new apparatus is suitable for continuous gas monitoring of the two species and their ratios, which are important geochemical indicators of volcanic activity, for which other reliable continuous monitoring systems are not yet available.222 349 - PublicationRestrictedSecondary hydrothermal minerals in buried rocks at the campi flegrei caldera, Italy: a possible tool to understand the rock-physics and to assess the state of the volcanic system(2011-12-13)
; ; ; ; ; ; ;Mormone, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Tramelli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Di Vito, M. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Piochi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Troise, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Natale, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; The distribution of the alteration assemblages and the related physico-chemical changes induced in the rocks with depth, may provide useful information on the state of the system. Drillholes are the only way to define hydrothermal alteration depth-profiles in variable geological contexts. Deep drillings exploiting programs were conducted since the 1970’s by the Agip-Enel Joint Venture in the Quaternary Campi Flegrei caldera (southern Italy), where a geothermal system has been active since at least historical times. New macroscopic and microscopic investigations were performed on selected samples made available by Agip in order to: 1) define the precursor lithology, 2) describe the relationships among texture, mineralogy and depth of the studied core samples and 3) examine the character of the secondary minerals and their distribution with depth and temperature. The new data are integrated with physical properties and elastic parameters of cored rocks, as well as structural information and field data, all available from the physical, seismological, geodetical and volcanological literature. The depth-related multi-parameters profiles provide evidence on the different behavior of the buried rocks beneath the Licola 1, Mofete and San Vito 1 areas, sited in three structurally different sectors of the caldera. The features of the hydrothermally altered rocks are a key to interpret the heterogeneities of the Campi Flegrei substratum, as deduced by velocity, attenuation and scattering P- and S- waves tomography. The time and space distribution of both the eruptive vents and the extruded magma volumes are consistent with the results of our analysis. Therefore, we interpret the observed Campi Flegrei geothermal system as a response to the distribution of volcanic activity in two structurally distinct sectors of the caldera. The central-eastern sector, where the San Vito 1 well was drilled, represents the preferential pathways for both gas escape and magma ascent at least since 8 kyrs, in contrast with the other sites of the caldera where eruptions occurred with minor frequency and magnitude.383 75 - PublicationOpen AccessUnderstanding volcanic hazard at the most populated caldera in the world: Campi Flegrei, Southern Italy(2017-04-16)
; ; ; ; ; ; ; ;; Naples and its hinterland in Southern Italy are one of the most urbanized areas in the worldunder threat from volcanic activity. The region lies within range of three active volcanic centers: Vesuvius,Campi Flegrei, and Ischia. The Campi Flegrei caldera, in particular, has been in unrest for six decades. Theunrest followed four centuries of quiescence and has heightened concern about an increased potential foreruption. Innovative modeling and scientific drilling are being used to investigate Campi Flegrei, and theresults highlight key directions for better understanding the mechanisms of caldera formation and the rolesof magma intrusion and geothermal activity in determining the volcano’s behavior. They also provide aframework for evaluating and mitigating the risk from this caldera and other large ones worldwide388 39 - PublicationRestrictedEvidence for a peculiar style of ground deformation inferred at Vesuvius volcano(2002-05-03)
; ; ; ; ; ; ; ; ; ;; ; ;; ; ; ; We present results obtained via an innovative spacebome SAR interferometry algorithm showing that the Somma-Vesuvius volcanic complex, despite of its quiescent stage, is subject lo a particular deformation process. This is characterized by a rather continuous subsidence, revealed by ERS satellite data and levelling surveys, between 1992 and 2000. These deformations are mainly localized in two zones involving the Vesuvius cone and a narrow annular area that, although not fully continuously, extends around the base of the Somma edifice. We propose an interpretation of subsidence at both sites involving joint effects of gravitational sliding and extensional tectonic stress occurring at the contact between different lithological units. Some simple elastic models show how such localized subsidence can be generated. These results shed new light on the Vesuvius dynamics and, more generally, on the link between gravitational effects of volcano loading and seismic-deformative processes, which is a subject of intense scientific debate.154 2 - PublicationRestrictedGeothermal Investigations of Active Volcanoes: The Example of Ischia Island and Campi Flegrei Caldera (Southern Italy)(2015)
; ; ; ; ; ; ; ; ; ; ; The active volcanic zone of Ischia Island and Campi Flegrei caldera (Campania) have been the site of many geothermal investigations, since the early 20th century. These areas are characterized by very high geothermal gradient and heat flow as consequence of upward migration of magmatic sources coupled with vigorous hydrothermal circulation. After the increment of installed geothermal power in Larderello (Tuscany), the extensive geothermal exploration of Campania was not followed by exploitation projects. In recent time, the attention on the possibility to exploit electric energy has been drawn by the new Italian regulation for exploitation leases. The larger geothermal potential of Campi Flegrei caldera and Ischia Island, located west to the Bay of Naples, makes these areas as possible sites of new geothermal plants installation. We present here the results of recent geothermal researches of Campi Flegrei caldera and Ischia Island, which integrate and improve the information obtained during the exploration performed by SAFEN and AGIP-ENEL companies from the earlier 1940 to 1985. These data are useful to characterize the geothermal reservoirs of this active volcanoes and also to increase the knowledge of volcanic processes and related risk.120 9 - PublicationOpen AccessA detailed analysis of some local earthquakes at Somma-Vesuvius(1999-06)
; ; ; ; ; ; ;Capuano, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Coppa, U.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Natale, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Di Sena, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Godano, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Troise, C.; Dipartimento di Geofisica e Vulcanologia, Università di Napoli "Federico II", Napoli, Italy; ; ; ; ; In this paper, we analyze local earthquakes which occurred at Somma-Vesuvius during two episodes of intense seismic swarms, in 1989 and 1995 respectively. For the selected earthquakes we have computed accurate hypocentral locations, focal mechanisms and spectral parameters. We have also studied the ground acceleration produced by the largest events of the sequences (ML 3.0), at various digital stations installed in the area during the periods of higher seismic activity. The main result is that seismicity during the two swarm episodes presents similar features in both locations and focal mechanisms. Strong site dependent effects are evidenced in the seismic radiation and strong amplifications in the frequency band 10-15 Hz are evident at stations located on the younger Vesuvius structure, with respect to one located on the ancient Somma structure. Furthermore, seismic stations show peak accelerations for the same events of more than one order of magnitude apart.197 360 - PublicationOpen AccessMonitoraggio della sismicità locale nel Cilento nel periodo febbraio-ottobre 2014(2015-05)
; ; ; ; ; ; ; ; ; ; ;La Rocca, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Galluzzo, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Gaudiosi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Nappi, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Margheriti, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Moretti, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Criscuoli, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Giovani, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;De Lucia, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Natale, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; ; ; ; ; Alcune stazioni sismiche temporanee sono state installate nel Cilento da febbraio a ottobre 2014 per monitorare la sismicità locale nella zona di Roccadaspide e Comuni limitrofi, dove due terremoti di magnitudo Mw=3.6 e Mw=3.7 sono avvenuti il 22 gennaio 2014. In seguito alle segnalazioni di boati e tremori riportate da cittadini che abitano nella zona, diffuse anche attraverso gli organi di stampa e le televisioni locali, è stato effettuato un sopralluogo ed è iniziato il monitoraggio dell'area. I dati acquisiti hanno mostrato una sequenza di microterremoti che verosimilmente è stata innescata dai due eventi avvenuti il 22 gennaio. Sono stati individuati oltre 750 terremoti molto piccoli (M<2) di cui oltre 60 sono stati localizzati. Il 95% delle sorgenti localizzate ricade in un'area di circa 10 km2 e la profondità è inferiore a 3 km. Per circa 15 terremoti registrati da almeno 5 stazioni è stato possibile calcolare anche il meccanismo focale. I risultati indicano una dinamica distensiva nell'area epicentrale, tuttavia il quadro complessivo risulta piuttosto complesso, con meccanismi molto diversi per terremoti localizzati molto vicino tra loro.901 153 - PublicationOpen AccessThe role of stress-dependent permeability in enhanced geothermal systems modelling(2014-07-02)
; ; ; ; ; ; ; We present a procedure for testing the interpretation of the induced seismicity. The procedure is based on Coulomb stress changes induced by deep fluid injection during well stimulation, providing a way to estimate how the potential for seismic failure in different volumes of a geothermal reservoir might change due to the water injection. It was successfully applied to reproduce the observations collected during and after the complex stimulation cycle of the GPK2 and GPK3 wells at the Soultz sous Foret Enhanced Geothermal System EGS site (Alsace, France). In this paper, a conceptual model that links the induced stress tensor and the permeability modifications is considered, with the aim to estimate the permeability change induced during the water injection. In this way, we can adapt the medium behaviour to mechanical changes, in order to better evaluate the effectiveness of the stimulation process for the enhancement of the reservoir permeability, while also refining the reconstruction of the Coulomb stress change patterns. Numerical tests have been developed that consider a physical medium comparable with the granitic basement of the Soultz EGS site, and a geometry of the system that is compatible with that of the GPK2-GPK3 wells. In such a way, the forecasting of the areas of higher likelihood for induced seismicity results in a good agreement between Coulomb stress change patterns and induced seismicity.89 37 - PublicationOpen AccessSmart working e Ricerca: il punto di vista dei Ricercatori e Tecnologi dell’INGV(2021-05-19)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Obiettivi: Le finalità di questo articolo sono quelle di sottolineare le specificità della Ricerca rispetto alla amministrazione. Metodologia: è stata svolta un’analisi qualitativa giuridico-normativa e una indagine online quantitativa a 585 ricercatori e tecnologi dell’INGV sullo smart working. Risultati: nell’articolo vengono richiamate le norme che affermano come le attività di ricerca e le attività gestionali debbono avere una valutazione diversa. Inoltre, il CCNL della sezione Ricercatori e Tecnologi già rende “smart” e “agile” il lavoro di ricerca senza ricadere nella legge sullo smart working. Le risposte all’indagine mostrano una forte coesione nel rivendicare i principi di autonomia e libertà della ricerca. Limiti e implicazioni: negli EPR si fa Ricerca e la Ricerca ha bisogno di flessibilità e specificità organizzativa rispetto ad una P.A. prevalentemente amministrativa e lo smart working mal si adatta al mondo della Ricerca. Originalità: il percorso bottom-up di rivendicazione dei diritti della ricerca, attraverso interviste online, è originale e innovativo per evidenziare l’analisi delle criticità del lavoro agile che non deve essere applicato senza considerare il modello rispondente alle proprie esigenze e caratteristiche.768 88