Papers by Giovanna Berrino
Journal of Volcanology and Geothermal Research, 2016
Understanding the dynamics of volcanic-hydrothermal systems is a key factor for discriminating be... more Understanding the dynamics of volcanic-hydrothermal systems is a key factor for discriminating between magmatic and hydrothermal nature of the sources responsible for the unrest phenomena observed in active volcanic areas. Numerous studies of geophysical data monitoring in volcano-geothermal districts has indeed proven that close relationships exist between the volcanic and hydrothermal fluid circulation and the anomalous geophysical signals observed at the ground surface. In this paper, a simultaneous analysis that integrates resistivity and gravity data is suggested as a useful tool to infer a consistent conceptual model of hydrothermal volcanic systems and their evolution. An application of the proposed analysis to repeated resistivity and gravity measurements performed on Vulcano Island (Aeolian Archipelago, Sicily, southern Italy) is presented with the aim of gaining information on the dynamics of the volcanic-hydrothermal system. The examined period ranges from December 1993 to September 1996, when significant changes in chemical properties, temperatures and emission rates of La Fossa crater fumaroles were observed, all indicating an increase in the flux of hot deep magmatic gases. The results of our analysis, which refers to a profile located at the foot of the northwest flank of La Fossa cone, suggest that underground cyclic water-to-vapour transformations govern the shallow hydrothermal system dynamics, generally described by a negative correlation between the monitored resistivity and gravity data. The occurrence of positive correlations between the two analysed parameters could be ascribed to volcanic dynamics, which would mask the normal hydrological and hydrothermal system behaviour.
The interpretation of the results of seismic velocity, attenuation and gravity inversion are usua... more The interpretation of the results of seismic velocity, attenuation and gravity inversion are usually based on the qualitative observation and comparison of the different tomographic images. A promising tool to jointly interpret tomographic models based on different parameters resides in the application of statistical classification methods, such as the k-means clustering method, which minimizes the logic distance among each group
Contributions to Geophysics and Geodesy, 2021
We analyse spatiotemporal gravity changes observed on the Ischia island (Italy) accompanying the ... more We analyse spatiotemporal gravity changes observed on the Ischia island (Italy) accompanying the destructive earthquake of 21 August 2017. The 29 May 2016 to 22 September 2017 time-lapse gravity changes observed at 18 benchmarks of the Ischia gravimetric network are first corrected for the gravitational effect of the surface deformation using the deformation-induced topographic effect (DITE) correction. The co-seismic DITE is computed by Newtonian volumetric integration using the Toposk software, a high-resolution LiDAR DEM and the co-seismic vertical displacement field derived from Sentinel-1 InSAR data. We compare numerically the DITE field with its commonly used Bouguer approximation over the island of Ischia with the outcome that the Bouguer approximation of DITE is adequate and accurate in this case. The residual gravity changes are then computed at gravity benchmarks by correcting the observed gravity changes for the planar Bouguer effect of the elevation changes at benchmarks...
Contributions to Geophysics and Geodesy, 2022
Bollettino Di Geofisica Teorica Ed Applicata, 1999
Gravity studies aimed at detecting volcanic inputs, precursors to a preeruptive state are in proc... more Gravity studies aimed at detecting volcanic inputs, precursors to a preeruptive state are in process on active Italian volcanoes. To achieve this goal high precision absolute and relative gravity measurements are carried out to identify time variations of the gravity field caused by the ascent of magmatic masses. Since 1980, gravity surveys have been carried out at Mt. Etna, the Aeolian Islands, Pantelleria, Ischia, Mt. Vesuvius and the Campi Flegrei. Absolute measurements of gravity acceleration date back to 1986 and are carried out on selected stations of the relative networks. The absolute stations work as a reference for the relative networks. Moreover, by periodically surveying them, they provide the long-term components for the temporal trend of gravity changes. Intercalibrated LaCoste & Romberg, model D, gravity meters are employed for relative gravity measurements. Absolute measurements of g are carried out by means of the ballistic Absolute Gravimeter (symmetrical rise and ...
Remote Sensing, 2021
In this study we present and discuss gravity and ground deformation variations, at different time... more In this study we present and discuss gravity and ground deformation variations, at different time scales, observed in a wide mesh absolute gravity and GNSS network set up in central Italy. The network was installed in the area affected by the 2009 (L’Aquila; Mw 6.1) and 2016 (Amatrice-Norcia; Mw 6.0 and 6.5) seismic activity, in order to verify if gravity and ground deformation variations could be related to seismic effects. The new network includes 5 stations distributed between the Lazio, Umbria, and Abruzzo regions. From 2018 to 2020 three campaigns were carried out using the transportable Micro-g LaCoste FG5#238 and the portable Micro-g LaCoste A10#39 absolute gravimeters and completed with two simultaneous GNSS measurements. Topographic instruments, measurement and analysis techniques enabling accurate measurements in the positioning of the stations and to control their variations over time were applied. The high reliability and accuracy of the absolute gravity data gathered, a...
Rendiconti Lincei. Scienze Fisiche e Naturali, 2020
Relative and absolute gravimetric measurements are carried out for metrological, geodetic and geo... more Relative and absolute gravimetric measurements are carried out for metrological, geodetic and geophysical (structural and dynamic) studies. Gravimetry is largely used in Italy since long time for vast set of studies. Both relative and absolute measurements are carried out in several fields of geodesy, geophysics and geodynamic with different approaches. After a brief historical excursus, the paper presents the state of the art of “Modern” gravimetry in Italy in its various applications, together the main available results and products, with particular attention to: Development of modern gravimetry in Italy: from relative to absolute measurements. Italian reference gravity networks: state of the art The Italian gravimetric map: its evolution over time, data, the present-day status and related products. Dynamic gravimetry: examples of applications in geodynamical areas. Finally, suggestions for future perspectives for gravimetry in Italy are outlined.
Advances in Geosciences, 2020
Since 1981, relative gravity measurements have routinely carried out at the Campi Flegrei caldera... more Since 1981, relative gravity measurements have routinely carried out at the Campi Flegrei caldera, a densely populated area. The gravity network also includes two absolute stations periodically measured with a laboratory absolute gravimeter, which does not permit field measurements. At the end of 2014, the Osservatorio Vesuviano, Section of Napoli of the Istituto Nazionale di Geofisica e Vulcanologia (INGV-OV), acquired a portable absolute gravimeter that allows field operations on outdoor sites. Therefore, in 2015 a dense absolute gravity network was established in Campi Flegrei. This will permit an advanced approach for volcano monitoring. The net consists of 36 stations, 34 of which located inside the caldera and placed upon or very close to gravity stations belonging to the relative network. Five surveys were carried out on June 2015, on February and November 2017, on October 2018 and on October 2019. The comparison with height changes suggests that significant g are partly due to the uplift occurred over the same time intervals and mostly to shallow processes associated to the dynamic of the local hydrothermal system. The comparison with the gradients observed during the last large uplift (1982-1984) and the following subsidence (1985-2003) confirms this observation. These results suggest that the present activity may be due to a transient or pulsating phenomenon as the alternating recharge/discharge of fluids in the surface hydrothermal system. Gravity changes detected by absolute measurements are in good agreement with those obtained by relative ones, and confirms the feasibility of this methodology for volcano monitoring. Finally, they also encourage replacing the relative networks with absolute ones, with all the consequent advantages.
Scientific reports, Jan 16, 2017
Existing 3-D density models of the Somma-Vesuvius volcanic complex (SVVC), Italy, largely disagre... more Existing 3-D density models of the Somma-Vesuvius volcanic complex (SVVC), Italy, largely disagree. Despite the scientific and socioeconomic importance of Vesuvius, there is no reliable 3-D density model of the SVVC. A considerable uncertainty prevails concerning the presence (or absence) of a dense body underlying the Vesuvius crater (1944 eruption) that is implied from extensive seismic investigations. We have acquired relative gravity measurements at 297 stations, including measurements in difficult-to-access areas (e.g., the first-ever measurements in the crater). In agreement with seismic investigations, the simultaneous inversion of these and historic data resolves a high-density body that extends from the surface of the Vesuvius crater down to depths that exceed 2 km. A 1.5-km radius horseshoe-shaped dense feature (open in the southwestern sector) enforces the existing model of groundwater circulation within the SVVC. Based on its volcano-tectonic evolution, we interpret volc...
dotto della matrice diagonale di covarianza Cp non sempre bastano a stabilizzare l’operazione di ... more dotto della matrice diagonale di covarianza Cp non sempre bastano a stabilizzare l’operazione di inversione. In questi casi la stabilita viene garantita tramite un approccio d’inversione ai valori singolari troncati (TSVD o pseudo-inversa di Moore-Penrose). Al fine ridurre il tempo computazionale per il calcolo della pseudo-inversa e migliorarne la stabilita, la stima dello spettro di Fourier viene effettuata su porzioni limitate di dato utilizzando delle finestre spaziali scorrevoli. Le Figure. 1c-d e 2c-d mostrano i risultati della regolarizzazione di Fourier, utilizzando sia l’informazione a priori che l’approccio TSVD, applicata ad un dato reale marino (singolo common-shot). dove l’andamento dei cavi devia sensibilmente rispetto alla geometria nominale: a corti offset sorgente-ricevitore (Fig.1a) e per offset sorgente-ricevitore superiori a 6500 m (Fig. 2a). In entrambe le finestre il dato regolarizzato mostra una buona continuita di ampiezza e fase. I risultati ottenuti rappres...
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Papers by Giovanna Berrino