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Scandura, Danila
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Scandura, Danila
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danila.scandura@ingv.it
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- PublicationOpen AccessProbability hazard map for future vent opening at Etna volcano (Sicily, Italy).(2014-12-15)
; ; ; ; ; ; ; ; ;Placido, Montalto; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Alfonso, Brancato; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Flavio, Cannavò; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Mauro, Coltelli; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Mario, Mattia; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Domenico, Patanè; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cristina, Proietti; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Danila, Scandura; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; ; ; The frequent flank eruptions occurrence at Mt. Etna lead to a high volcanic hazard that, linked to a population of nearly one million people dwell on its flanks, poses a high volcanic risk. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management), we developed a near real-time computer-assisted analysis and probabilistic evaluations that provide the identification of the areas prone to the highest vent opening hazard. The use of a code such BET_EF (Bayesian Event Tree_Eruption Forecasting) provide us a long-term hazard map mainly based on the past behaviour of the Etna volcano. The near real-time additional seismic and ground deformation data allow the long-term hazard map switches into a short-term future vent opening one. The short-term future vent opening was computed starting from the evaluation of deformation field over Etna surface. Analytical inversion of deformation and seismic data is performed to find the parameters of a magmatic source in an elastic, isotropic and homogeneous half-space and forward model is performed to compute the displacement field over Etna surface. We modelled the final intrusion of the Mount Etna May 2008 eruption that was accompanied by a violent seismic swarm and marked by ground deformation recorded at GPS stations. Results suggest a good accordance between the higher probability area and the real vent occurrence.260 44 - PublicationOpen AccessProcedura near real-time per la valutazione dell’hazard da eruzioni laterali all’Etna (Sicilia, Italia)(2017)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; L’Etna è uno stratovulcano composito situato lungo la costa ionica della Sicilia. Le frequenti eruzioni laterali (soprattutto lungo i Rift NE, S e O) fanno sì che ad esso sia associata una elevata pericolosità vulcanica. Se valutiamo anche l’elevato tasso di urbanizzazione dei suoi fianchi risulta evidente il notevole valore esposto al pericolo. Nel quadro del progetto PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management), abbiamo sviluppato un’analisi in tempo quasi reale e completamente automatizzata volta alla valutazione delle aree soggette alla più alta probabilità di apertura di bocche effusive (vent) e il corrispondente hazard relativo all’accadimento di eruzioni effusive. L’algoritmo bayesiano BET_EF (Bayesian Event Tree_Eruption Forecasting), basato sull’albero degli eventi, è, nel nostro approccio, utilizzato inizialmente per la valutazione di una mappa di pericolosità a lungo termine sulla base dell’attività effusiva degli ultimi 4000 anni. L’analisi e l’inversione dei parametri monitorati in tempo reale, quali, ad esempio, dati sismici e sorgenti di tremore vulcanico, permette di valutare la funzione di densità di probabilità (PDF) a breve termine. Un’ulteriore applicazione dell’algoritmo BET_EF fornisce uno scenario, in termini di mappa di pericolosità, a breve termine per le simulazioni delle colate laviche. L’output della seconda applicazione del BET_EF costituisce l’input per simulare una serie di colate laviche e valutare il relativo hazard, definito in termini di impatto sul territorio. Allo scopo di testare limiti e utilità del nostro approccio integrato, abbiamo utilizzato, come test case, la fase intrusiva iniziale dell’eruzione laterale accaduta all’Etna nel maggio 2008. La previsione di apertura di vent evidenzia la zona con maggiore probabilità e, dall’analisi dei risultati, si nota un buon accordo tra l’area a probabilità più alta e la posizione effettiva del vent. È stata eseguita una serie di 200 simulazioni di colate per valutare le aree soggette a più alta probabilità di invasione lavica. Infine, è stata valutata la densità dei flussi simulati e i valori più alti sono risultati in accordo con l’area effettivamente coperta dal campo lavico dell’eruzione considerata.874 44 - PublicationOpen AccessDome-like behaviour at Mt. Etna: The case of the 28 December 2014 South East Crater paroxysm(2017-07-13)
; ; ; ; ; ; ; ;; ; ; ; ; On the 28 December 2014, a violent and short paroxysmal eruption occurred at the South East Crater (SEC) of Mount Etna that led to the formation of huge niches on the SW and NE flanks of the SEC edifice from which a volume of ~3 × 106 m3of lava was erupted. Two basaltic lava flows discharged at a rate of ~370 m3/s, reaching a maximum distance of ~5 km. The seismicity during the event was scarce and the eruption was not preceded by any notable ground deformation, which instead was dramatic during and immediately after the event. The SO2flux associated with the eruption was relatively low and even decreased few days before. Observations suggest that the paroxysm was not related to the ascent of volatile-rich fresh magma from a deep reservoir (dyke intrusion), but instead to a collapse of a portion of SEC, similar to what happens on exogenous andesitic domes. The sudden and fast discharge eventually triggered a depressurization in the shallow volcano plumbing system that drew up fresh magma from depth. Integration of data and observations has allowed to formulate a novel interpretation of mechanism leading volcanic activity at Mt. Etna and on basaltic volcanoes worldwide.698 158 - PublicationOpen AccessInflation Leading to a Slow Slip Event and Volcanic Unrest at Mount Etna in 2016: Insights From CGPS Data(2017-11-15)
; ; ; ; ; ; ; ; ; Global Positioning System (CGPS) data from Mount Etna between May 2015 and September 2016 show intense inflation and a concurrent Slow Slip Event (SSE) from 11 December 2015 to 17 May 2016. In May 2016, an eruptive phase started from the summit craters, temporarily stopping the ongoing inflation. The CGPS data presented here give us the opportunity to determine (1) the source of the inflating body, (2) the strain rate parameters highlighting shear strain rate accumulating along NE Rift and S Rift, (3) the magnitude of the SSE, and (4) possible interaction between modeled sources and other flank structures through stress calculations. By analytical inversion, we find an inflating source 5.5 km under the summit (4.4 km below sea level) and flank slip in a fragmented shallow structure accommodating displacements equivalent to a magnitude Mw6.1 earthquake. These large displacements reflect a complex mechanism of rotations indicated by the inversion of CGPS data for strain rate parameters. At the scale of the volcano, these processes can be considered precursors of seismic activity in the eastern flank of the volcano but concentrated mainly on the northern boundary of the mobile eastern flank along the Pernicana Fault and in the area of the Timpe Fault System.694 47 - PublicationRestrictedProbability hazard map for future vent opening at Etna volcano (Sicily, Italy).(2014-10-29)
; ; ; ; ; ; ;Alfonso, Brancato; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Mauro, Coltelli; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Placido, Montalto; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Domenico, Patanè; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cristina, Proietti; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Danila, Scandura; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; Mount Etna is a composite stratovolcano located along the Ionian coast of eastern Sicily. The frequent occurrence of flank eruptions (at an interval of years), mostly concentrated along the NE, S and W rift zones leads to a high volcanic hazard that, linked with intense urbanization, poses a high volcanic risk. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management), we develop a near real-time computer-assisted analysis and probabilistic evaluations that provides the identification of the areas prone to the highest vent opening hazard. A longterm volcanic hazard assessment, mainly based on the past flank activity of the Mt. Etna volcano, is the basic tool for the evaluation of this risk. Then, a reliable forecast of where an impending eruption will occur is needed. The use of a code such BET_EF (Bayesian Event Tree_Eruption Forecasting) delivers a long-term hazard map, that, if additional data are provided, switches into a short-term future vent opening map. The present application is based on incoming seismic and ground deformation data. Analytic inversion of high frequencies deformation data is performed to find the key parameters of a magmatic source in an elastic, isotropic and homogeneous half-space. Seismic data allow us to set the boundary of the investigated area. The inversion is performed by using the genetic algorithms (GAs) approach, a well-known search technique widely used to solve optimization problems and categorized as global search heuristics (Goldberg, 1989). Hence the magmatic source is located, a forward model is computed to evaluate the deformation field over Mt. Etna surface. Therefore, for each cell, the displacement vector modulus is estimated and the density probability function is calculated. A higher probability value matches with the cells with larger modulus, whereas lower estimate is found where the modulus is close to zero, being the sum of the probability values normalized to one over the investigated area. We modelled the final intrusion of the May 2008 – July 2009 flank eruption at Mt. Etna, whose onset was preceded by an intense seismic swarm and marked by ground deformation recorded at GPS stations. The future vent forecast highlights the area with higher probability, increasing the difference in relative values between that zone and the rest of the volcano edifice. It is worthy notice that a good accordance is evident if the highest probability area is compared with the real vent occurrence.231 19 - 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 1755 - PublicationRestrictedElasto-plastic modeling of volcano ground deformation(2010)
; ; ; ; ; ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Bonaccorso, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Scandura, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Boschi, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; ; ; ; Elasto-plastic models for pressure sources in heterogeneous domain were constructed to describe, assess, and interpret observed deformation in volcanic regions. We used the Finite Element Method (FEM) to simulate the deformation in a 3D domain partitioned to account for the volcano topography and the heterogeneous material properties distribution. Firstly, we evaluated the extent of a heated zone surrounding the magmatic source calculating the temperature distribution by a thermo-mechanical numerical model. Secondly, we included around the pressurized magma source an elasto-plastic zone, whose dimension is related to the temperature distribution. This elasto-plastic model gave rise to deformation comparable with that obtained from elastic and viscoelastic models, but requiring a geologically satisfactory pressure. We successfully applied the method to review the ground deformation accompanying the 1993–1997 inflation period on Mt Etna. The model considerably reduces the pressure of a magma chamber to a few tens of MPa to produce the observed surface deformation. Results suggest that the approach presented here can lead to more accurate interpretations and inferences in future modeling-based assessments of volcano deformation.175 30 - 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.279 313 - PublicationRestricted3D numerical deformation model of the intrusive event forerunning the 2001 Etna eruption(2008)
; ; ; ; ;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 ;Scandura, D.; Università Catania; ; ; 3D finite elements models were carried out in order to evaluate the ground deformation produced by the dike intrusion occurred at Etna volcano in the 2001. The finite element method (FEM) allows for considering the medium heterogeneity and the real topography of the volcano. Firstly, we validated the method in ahomogeneous elastic half-space andcompared the results with those obtained fromanalytical dislocation models. We performed a convergence analysis to quantify the discretization errors, which are sensitive to the size and quality of the mesh elements and can cause inaccurate numerical solutions. Secondly, several numerical modelswere conducted to appreciate howthe complex distribution of elastic medium parameters and the topography make the numerical results differ from the simple analytical solutions. The numerical model, which account for the real topography of Etna volcano and medium heterogeneity, well match the ground deformation observed at the GPS stations between 11 and 16 July 2001. It appears that topography and heterogeneities provide more details about the ground deformation near the summit crater area that are missed when homogeneous half-space models are used. However, only fewdiscrepancies between the analytical and the numerical models are observed at the GPS stations, which coarsely sample the volcanic edifice far away from the summit craters.177 26 - PublicationRestrictedDesign and application of an adaptive nonstationary filter for noise reduction in volcanomagnetic monitoring at Mt Etna(2011)
; ; ; ; ; ; ;Napoli, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Pistorio, A.; Dip. Ing. Elettrico, Elettronico e Sistemistico Università Catania ;Scandura, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Greco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; Volcanomagnetic monitoring is critically dependent on the ability to detect and isolate local magnetic variations related to volcanic activity. Accurate detection of volcanomagnetic anomalies attributable to the dynamics of volcanoes requires removal from measurements of the Earth’s magnetic field, fluctuations of external origin which may be up to hundreds of nanotesla during geomagnetic storms. The commonly used method of taking simple differences of the total intensity with respect to the simultaneous value at a remote reference is only partially successful. Variations in the difference fields are thought to arise principally from contrasting electromagnetics of rock properties at magnetometer sites. With the aim of improving the noise reduction of geomagnetic time series from the magnetic network of Mt Etna, we developed an adaptive filtering. Magnetic vector data are included as input to the filter, to account for the orientation of the magnetic field. The filter is able to estimate and adapt the model parameters continuously by means of the new observations, so that the estimated signal closely matches the observed data. Therefore, the filtering accuracy is improved in order to reduce the residual components. Experimental data collected on Mt Etna during 2010 are analysed to relate the field variation at a given station to the field at other sites, filtering out undesired noise and enhancing signal-to-noise ratio.266 27