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Currenti, Gilda
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Currenti, Gilda
Email
gilda.currenti@ingv.it
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staff
ORCID
Scopus Author ID
6506592199
Researcher ID
I-3136-2017
92 results
Now showing 1 - 10 of 92
- PublicationOpen AccessEffects of hydrothermal unrest on stress and deformation: insights from numerical modeling and application to Vulcano Island (Italy)(2017)
; ; ; ; ; ; ;A numerical approach is proposed to evaluate stress and deformation fields induced by hydrothermal fluid circulation and its influence on volcano-flank stability. The numerical computations have been focused on a conceptual model of Vulcano Island, where geophysical, geochemical, and seismic signals have experienced several episodes of remarkable changes likely linked to the hydrothermal activity. We design a range of numerical models of hydrothermal unrest and computed the associated deformation and stress field arising from rock-fluid interaction processes related to the thermoporoelastic response of the medium. The effects of model parameters on deformation and flank stability are explored considering different multilayered crustal structures constrained by seismic tomography and stratigraphy investigations. Our findings highlight the significant role of model parameters on the response of the hydrothermal system and, consequently, on the amplitudes and the timescale of stress and strain fields. Even if no claim is made that the model strictly applies to the crisis episodes at Vulcano, the numerical results are in general agreement with the pattern of monitoring observations, characterized by an enhancing of gas emission and seismic activity without significant ground deformation.The conceptual model points to a pressurization and heating of the shallow hydrothermal system (1–0.25 km bsl) fed by fluid of magmatic origin. However, for the assumed values of model material and source parameters (rate of injection, fluid composition, and temperature), the pressure and temperature changes do not affect significantly the flank stability, which is mainly controlled by the gravitational force.494 39 - PublicationRestrictedMagnetic features of the magmatic intrusion that occurred in the 2007 eruption at Stromboli Island (Italy)(2011)
; ; ; ; ; ; ;Napoli, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Di Stefano, A.; Dip. Ing. Elettrica, Elettronica e dei Sistemi Università di Catania, ;Greco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Boschi, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; ; ; ; ; Significant changes in the local magnetic field marked the resumption of eruptive activity at Stromboli volcano on February 27, 2007. After differential magnetic fields were obtained by filtering out external noise using adaptive filters and seasonal thermal noise using temperature data, we identified step-like changes of 1–4 nT coincident with the opening of eruptive fissures in the upper part of the Sciara del Fuoco. The magnetic variations detected at two stations are closely related to the propagation of a shallow NE–SW magmatic intrusion extending beyond the summit craters area. These observations are consistent with those calculated using piezomagnetic models in which stress-induced changes in rock magnetization are produced by the magmatic intrusion. No significant magnetic changes were observed when the first fractures opened along the NE crater rim. Indeed, the stressinduced magnetization caused by this magmatic activity is expected to be too low because of the structural weakness and/or thermal state of the summit area. The continuous long-term decay characterizing the post-eruptive magnetic pattern can be related to a time-dependent relaxation process. A Maxwell rheology was assumed and the temporal evolution of the piezomagnetic field was evaluated. This allowed us to estimate the rheological properties of the medium; in particular, an average viscosity ranging between 1016 and 1017 Pa⋅s was a relaxation time τ of about 38 days.233 19 - PublicationRestrictedScaling characteristics of local geomagnetic field and seismicity at Etna volcano and their dynamics in relation to the eruptive activity(2005-06-30)
; ; ; ; ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Lapenna, V.; Istituto di Metodologie per l'Analisi Ambientale, Consiglio Nazionale delle Ricerche,Tito (PZ), Potenza, Italy ;Telesca, L.; Istituto di Metodologie per l'Analisi Ambientale, Consiglio Nazionale delle Ricerche,Tito (PZ), Potenza, Italy; ; ; The evolution of scaling characteristics of the local geomagnetic field and of the seismicity at Etna volcano is studied in relation to the strong eruptive activity occurred here from 2000 to 2002. Scaling laws are found in the hourly time variability of magnetic data and in the seismicity pattern. The scaling exponents suggest the presence of persistent temporal fluctuations. Clear links between the dynamics of the measured data and the eruptive volcanic episodes are revealed. Fractal dimensions of seismicity seem to be always correlated to the beginning of main eruptive events, while strong alterations of the dynamics of the local magnetic field take place only when the eruptive fractures opened very close to the magnetic sites.148 82 - PublicationRestrictedThe borehole dilatometers network of Mt. Etna : a powerful tool to detect and infer volcano dynamics(2016)
; ; ; ; ; ;Bonaccorso, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Linde, A.; Terrestrial Magnetism, Carnegie Institution, Washington, District of Columbia, USA ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Sacks, S.; Terrestrial Magnetism, Carnegie Institution, Washington, District of Columbia, USA ;Sicali, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ;; ;A network of four borehole dilatometers has been installed on Etna in two successive phases (2010–2011 and 2014). The borehole dilatometers are installed in holes drilled at depths usually greater than 100 m, and they measure the volumetric strain of the surrounding rock with a nominal precision up to 10^-11 in a wide frequency range (10^-7–25 Hz). Here we describe the characteristics of the network and the results of the in situ calibrations obtained after the installations by different methods. We illustrate short-term strain changes recorded during several lava fountains erupted by Etna during 2011–2013, and we also show signal changes recorded at all four stations during the lava fountain on 28 December 2014. Analytical and numerical computations constrained the eruptions source depth and also its volume change that is related to the magma volume emitted. Finally, we show the potential of the signal in the medium term to reveal strain changes related to different phases of the volcanic activity.494 10 - PublicationOpen AccessImaging the Salinelle Mud Volcanoes (Sicily, Italy) using integrated geophysical and geochemical surveys(2020)
; ; ; ; ; ; ; ; ; Geochemical and geophysical prospecting methods (including measurements of soil heat flux and soil CO2 flux, gravimetry, self-potential and geomagnetism) are used to produce an integrated data set aimed at imaging the migration of fluids in the sub-surface at the Salinelle mud volcanoes, located on the lower southwestern flank of Mt Etna (Sicily, Italy). This area was affected by magmatic eruptions from local volcanic centers between about 48 and 27 ka. Today, only pseudo-volcanic phenomena due to over-pressured multiphase pore fluids there occur. Carbon dioxide of magmatic origin, mixed with biogenic hydrocarbons, warm hypersaline waters and mud, are constantly released at the surface through the main conduits of mud volcanoes, whose activity is characterized by alternation of mild gas bubbling periods and strong paroxysmal phases. The latter produce violent gas eruptions that eject warm water (T ≈ 50° C) to a height up to about 1 m. Surface distribution of the geophysical and geochemical parameters have been investigated to detect the main pathways through which fluids move toward the shallow crust. Integration of geochemical, geophysical and geological maps allowed for the tracing of the fluid flow in the shallowest (a few tens of meters below the surface) part of the local hydrothermal system. Our results showed that the rising of fluids from a deep reservoir is controlled by the main structural and geological features of the area and their temporal and spatial evolution depends on pressure conditions inside the hydrothermal system.1063 55 - PublicationOpen AccessABSOLUTE AND RELATIVE GRAVITY MEASUREMENTS AT ETNA VOLCANO (ITALY)(2010-06-22)
; ; ; ; ; ; ; ; ; ; ; ;Greco, Filippo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Currenti, Gilda; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;D'Agostino, Giancarlo; Istituto Nazionale di Ricerca Metrologica, INRiM, Torino, Italy, ;Del Negro, Ciro; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Di Stefano, Agnese; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Germak, Alessandro; Istituto Nazionale di Ricerca Metrologica, INRiM, Torino, Italy, ;Napoli, Rosalba; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Origlia, Claudio; Istituto Nazionale di Ricerca Metrologica, INRiM, Torino, Italy, ;Pistorio, Antonio; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Scandura, Danila; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Sicali, Antonino; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; ; ; ; ; ; ; ; ;Peshekhonov, Vladimir G.; Academician of the RASEmploying both absolute and relative gravimeters, we carried out three hybrid microgravity surveys at Etna volcano between 2007 and 2009. The repeated measurements highlighted the spatio-time evolution of the gravity field associated with the volcanic unrest. We detected a gravity increase attained an amplitude of about 80 µGal on the summit area of the volcano between July 2008 and July 2009. The observed gravity increase could reflect mass accumulations into shallow magma storage system of the volcano located at 1÷2 km below sea level. We present here data and the advantages in using the combined approach of relative and absolute measurements performed at Etna volcano.279 312 - PublicationRestrictedA second order finite-difference ghost-point method for elasticity problems on unbounded domains with applications to volcanology(2014)
; ; ; ; ;Coco, A.; Bristol University ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Russo, G.; Università di Catania; ; ; We propose a novel nite-di erence approach for the numerical solution of linear elasticity problems in arbitrary unbounded domains. The method is an extension of a recently proposed ghost-point method for the Poisson equation on bounded domains with arbitrary boundary conditions (Coco, Russo, JCP, 2013) to the case of the Cauchy-Navier equations on unbounded domains. The technique is based on a smooth coordinate transformation, which maps an unbounded domain into a unit square. Arbitrary geometries are de ned by suitable level-set functions. The equations are discretized by classical ninepoint stencil on interior points, while boundary conditions and high order reconstructions are used to de ne the eld variable at ghost-point, which are grid nodes external to the domain with a neighbor inside the domain. The approach is then adopted to solve elasticity problems applied to volcanology for computing the displacement caused by an underground pressure source. The method is suitable to treat problems in which the geometry of the source often changes (explore the e ects of di erent scenarios, or solve inverse problems in which the geometry itself is part of the unknown), since it does not require complex re-meshing when the geometry is modi ed. Several numerical tests are performed, which asses the e ectiveness of the present approach. Keywords: Linear Elasticity, Cauchy-Navier equations, ground deformation, unbounded domain, coordinate transformation method, Cartesian grid, Ghost points, Level-set methods245 46 - PublicationRestrictedModelling of ground deformation and gravity fields using finite element method: an application to Etna volcano(2007)
; ; ; ;INGV - Sezione Catania ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Ganci, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; Elastic finite element models are applied to investigate the effects of topography and medium heterogeneities on the surface deformation and the gravity field produced by volcanic pressure sources. Changes in the gravity field cannot be interpreted only in terms of gain of mass disregarding the ground deformation of the rocks surrounding the source. Contributions to gravity changes depend also on surface and subsurface mass redistribution driven by dilation of the volcanic source. Both ground deformation and gravity changes were firstly evaluated by solving a coupled axi-symmetric problem to estimate the effects of topography and medium heterogeneities. Numerical results show significant discrepancies in the ground deformation and gravity field compared to those predicted by analytical solutions, which disregard topography, elastic heterogeneities and density subsurface structures. With this in mind, we reviewed the expected gravity changes accompanying the 1993-1997 inflation phase on Mt Etna by setting up a fully 3D finite element model in which we used the real topography, to include the geometry, and seismic tomography, to infer the crustal heterogeneities. The inflation phase was clearly detected by different geodetic techniques (EDM, GPS, SAR and leveling data) that showed a uniform expansion of the overall volcano edifice. When the gravity data are integrated with ground deformation data and a coupled FEM modeling was solved, a mass intrusion could have occurred at depth to justify both ground deformation and gravity observations.121 21 - PublicationOpen Access4D Hybrid Microgravity Measurements: Two Case Studies of Monitoring at Mt. Etna Volcano and at a Gas Storage Reservoir in Northern Italy(2011)
; ; ; ; ; ; ;Greco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Pistorio, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Napoli, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Scandura, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; Detection of clear gravity signals associated with the renewal of the volcanic activity and the emerging need of characterizing the dynamic changes of subsurface systems have led to increased application of the microgravity method in time-lapsed monitoring, also known as 4D gravity approach. Conventionally, microgravity measurements have been carried out using relative gravimeters, which measure spatial changes with respect to a fixed reference site. Since 2007, with the aim of comparing relative microgravity measurements routinely acquired on Etna with absolute gravity observations, we performed repeated surveys using transportable absolute gravimeters.491 1752 - PublicationOpen AccessMagma Migration at Shallower Levels and Lava Fountains Sequence as Revealed by Borehole Dilatometers on Etna Volcano(2021-09-08)
; ; ; ; ; ; ; A main challenge in open conduit volcanoes is to detect and interpret the ultra-small strain (<10–6) associated with minor but critical eruptions such as the lava fountains. Two years after the flank eruption of December 2018, Etna generated a violent and spectacular eruptive sequence of lava fountains. There were 23 episodes from December 13, 2020 to March 31, 2021, 17 of which in the brief period 16 February to 31 March with an intensified occurrence rate. The high-precision borehole dilatometer network recorded significant strain changes in the forerunning phase of December 2020 accompanying the final magma migration at the shallower levels, and also during the single lava fountains and during the entire sequence. The source modeling provided further information on the shallow plumbing system. Moreover, the strain signals also gave useful information both on the explosive efficiency of the lava fountains sequence and the estimate of erupted volume. The high precision borehole dilatometers confirm to be strategic and very useful tool, also to detect and interpret ultra-small strain changes associated with explosive eruptions, such as lava fountains, in open conduit volcanoes.508 16