Options
Montalto, Placido
Loading...
Preferred name
Montalto, Placido
Email
placido.montalto@ingv.it
Staff
staff
ORCID
Scopus Author ID
23489549800
66 results
Now showing 1 - 10 of 66
- PublicationOpen AccessImplementazione di una nuova procedura per caratterizzare la forma di particelle mediante misure al CAMSIZER e algoritmi di clustering(2011)
; ; ; ; ; ;Lo Castro, M. D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Andronico, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cassisi, C.; Università degli Studi di Catania ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Prestifilippo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; In this work we present the calibration phase of a new procedure for the characterization of the shape of pyroclastic particles. This research has been granted by INGV of Catania, with funds deriving from the “Progetto Giovani”, in collaboration with Retsch Technology in Haan. The innovation of this procedure arises from the use of CAMSIZER (an instrument developed by the German leader company). This instrument permits to obtain very important information both on size and shape parameters of a high number of particles (hundreds of thousands data). Moreover, we used clustering and classification algorithms in order to group particles according to their morphologic characteristics. This calibration phase has been tested only on standard materials with regular geometries such as cubes, spheres and cylinders. In the future we will apply this methodology to volcanic ash particles that, as well-known, are characterized by irregular morphologies.593 445 - PublicationRestrictedMultivariate time series clustering on geophysical data recorded at Mt. Etna from 1996 to 2003(2013)
; ; ; ; ; ;Di Salvo, R.; Dipartimento di Ingegneria Elettrica, Elettronica e Informatica, Università degli Studi di Catania, Facoltà di Ingegneria, Italy ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Nunnari, G.; Dipartimento di Ingegneria Elettrica, Elettronica e Informatica, Università degli Studi di Catania, Facoltà di Ingegneria, Italy ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Puglisi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; Time series clustering is an important task in data analysis issues in order to extract implicit, previously unknown, and potentially useful information froma large collection of data. Finding useful similar trends inmultivariate time series represents a challenge in several areas including geophysics environment research. While traditional time series analysis methods deal only with univariate time series, multivariate time series analysis is a more suitable approach in the field of researchwhere different kinds of data are available. Moreover, the conventional time series clustering techniques do not provide desired results for geophysical datasets due to the huge amount of data whose sampling rate is different according to the nature of signal. In this paper, a novel approach concerning geophysical multivariate time series clustering is proposed using dynamic time series segmentation and Self Organizing Maps techniques. This method allows finding coupling among trends of different geophysical data recorded from monitoring networks at Mt. Etna spanning from 1996 to 2003, when the transition from summit eruptions to flank eruptions occurred. This information can be used to carry out a more careful evaluation of the state of volcano and to define potential hazard assessment at Mt. Etna.464 24 - PublicationOpen AccessInterplay between Tectonics and Mount Etna’s Volcanism: Insights into the Geometry of the Plumbing System(2011)
; ; ; ; ; ; ; ; ;Patanè, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Aliotta, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cannata, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cassisi, C.; Università degli studi di Catania, Dipartimento di Matematica e Informatica, Catania, Italy ;Coltelli, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Di Grazia, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Zuccarello, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; ; ; ; ; ;Schattner, Uri; Charney School of Marine Sciences, University of Haifa, IsraelMt. Etna lies in front of the southeast-verging Apennine-Maghrebian fold-and-thrust belt, where the NNW-trending Malta Escarpment separates the Sicilian continental crust from the Ionian Mesozoic oceanic basin, presently subducting beneath the Calabrian arc (Selvaggi and Chiarabba, 1995). Seismic tomographic studies indicate the presence of a mantle plume beneath the volcano with a Moho transition at depth less than 20 km (Nicolich et al.,2000; Barberi et al., 2006). Geophysical and geological evidences suggest that the Mt. Etna magma ascent mechanism is related to the major NNW-trending lithospheric fault (Doglioni et al., 2001). However, the reason for the Mt. Etna mantle plume draining and channeling the magma from the upper mantle source to the surface is not yet clear. All models proposed in literature (Rittmann, 1973; Tanguy et al., 1997; Monaco et al.; 1997; Gvirtzman and Nur, 1999; Doglioni et al., 2001) do not explain why such a mantle plume has originated in this anomalous external position with respect to the arc magmatism and back-arc spreading zones associated with the Apennines subduction. Some ideas on the subduction rollback must be better developed through the comparison with new regional tomographic studies that are being released. Moreover, tomographic studies reveal a complex and large plumbing system below the volcano from -2 to -7 km a.s.l., wide up to 60 km2 that reduces itself in size down to -18 km of depth close to the apex of the mantle plume. Chiocci et al. (2011) found a large bulge on the underwater continental margin facing Mt. Etna, and suggested that the huge crystallized magma body intruded in the middle and upper continental crust was able to trigger an instability process involving the Sicilian continental margin during the last 0.1 Ma. This phenomenon induces the sliding of the volcano eastern flank observed since the 90s (Borgia et al, 1992; Lo Giudice and Rasà, 1992) because the effects of the bulge collapse are propagating upslope, and the continuous decompression at the volcano summit favors the ascent of basic magma without lengthy storage in the upper crust, as one might expect in a compressive tectonic regime. Taken together, these new evidences (tomographic, tectonic, volcanic) are concerned with the exceptional nature of Mt. Etna and raise the need to explain the origin of the mantle plume that supplies its volcanism. The lower crust and the uppermost mantle need to be better resolved in future experiments and studies. The use of regional and teleseismic events for tomography and receiver function analyses is required to explore a volume that has only marginally been investigated to date. The relation between the magma source in the mantle and the upper parts of the system, as well as the hypothesis above reported on the relation between tectonics and volcanism and the role of lithospheric faults, could be resolved only by applying seismological techniques able to better constrain broader and deeper models. Finally, although the recent tomographic inversions have progressively improved our knowledge of Etna’s shallow structure, highlighting a complex pattern of magma chambers and conduits with variable dimensions, the geometry of the conduits and the dimensions and shapes of small magmatic bodies still require greater investigation. Their precise definition is crucial to delineate a working model of this volcano in order to understand its behaviour and evolution. For this purpose, at least within the volcanic edifice, the precise locations of the seismo-volcanic signals can be considered a useful tool to constrain both the area and the depth range of magma degassing and the geometry of the shallow conduits. In this work, we furnish evidences that the tremor and LP locations allowed to track magma migration during the initial phase of the 2008-2009 eruption and in particular the initial northward dike intrusion, also confirmed by other geophysical, structural and volcanological observations (Aloisi et al., 2009; Bonaccorso et al., 2011), and the following fissure opening east of the summit area at the base of SEC. All these evidences, obtained by the marked improvement in the monitoring system together with the development of new processing techniques, allowed us to constrain both the area and the depth range of magma degassing, highlighting the geometry of the magmatic system feeding the 2008-2009 eruption.345 435 - PublicationOpen AccessSimilarity Measures and Dimensionality Reduction Techniques for Time Series Data Mining(Intech, 2012)
; ; ; ; ; ;Cassisi, C.; Dipartimento di Matematica e Informatica, Universita` degli studi di Catania, Catania, Italy ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Aliotta, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cannata, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Pulvirenti, A.; Dipartimento di Matematica e Informatica, Universita` degli studi di Catania, Catania, Italy; ; ; ; ; ; ;Karahoca, A.; Bahcesehir University, Engineering FacultyThe chapter is organized as follows. Section 2 will introduce the similarity matching problem on time series. We will note the importance of the use of efficient data structures to perform search, and the choice of an adequate distance measure. Section 3 will show some of the most used distance measure for time series data mining. Section 4 will review the above mentioned dimensionality reduction techniques.445 1455 - PublicationOpen AccessA Dynamic Bayesian Network for Mt. Etna Volcano State Assessment(2015-04-17)
; ; ; ; ; ; ;Cannavò, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cassisi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Aliotta, M; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cannata, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Prestifilippo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; Nowadays, the real-time monitoring of Mt. Etna volcano is mostly delegated to one or more human experts in volcanology, who interpret the data coming from different kind of monitoring networks. Among their duties, the evaluation of the volcano state is one of the most critical task for civil protection purposes. Unfortunately, the coupling of highly non-linear and complex volcanic dynamic processes leads to measurable effects that can show a large variety of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded data the volcano state needs to be expressed in probabilistic terms, thus making the fast volcano state assessment sometimes impracticable for the personnel on duty at the 24h control room. With the aim of aiding the personnel on duty in volcano monitoring, here we present an expert system approach based on Bayesian networks to estimate automatically the ongoing volcano state from all the available different kind of measurements. A Bayesian network is a static probabilistic graphical model that represents a set of random variables and their conditional dependencies via a directed acyclic graph. We consider model variables both the measurements and the possible states of the volcano. In order to include the time in the model, we use a Dynamic Bayesian Network (DBN) which relates variables to each other over adjacent time steps. The model output consists of an estimation of the probability distribution of the feasible volcano states. We build the model by considering the long record of data from 2011 to 2014 and we cross-validate it by considering 3 years for parameter estimation and 1 year for testing in simulated real-time mode.240 120 - 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 AccessJoint analysis of infrasound and seismic signals by cross wavelet transform: detection of Mt. Etna explosive activity(2013)
; ; ; ;Cannata, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Patanè, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; The prompt detection of explosive volcanic activity is crucial since this kind of activity can release copious amounts of volcanic ash and gases into the atmosphere, causing severe dangers to aviation. In this work, we show how the joint analysis of seismic and infrasonic data by wavelet transform coherence (WTC) can be useful to detect explosive activity, significantly enhancing its recognition that is normally done by video cameras and thermal sensors. Indeed, the efficiency of these sensors can be reduced (or inhibited) in the case of poor visibility due to clouds or gas plumes. In particular, we calculated the root mean square (RMS) of seismic and infrasonic signals recorded at Mt. Etna during 2011. This interval was characterised by several episodes of lava fountains, accompanied by lava effusion, and minor strombolian activities. WTC analysis showed significantly high values of coherence between seismic and infrasonic RMS during explosive activity, with infrasonic and seismic series in phase with each other, hence proving to be sensitive to both weak and strong explosive activity. The WTC capability of automatically detecting explosive activity was compared with the potential of detection methods based on fixed thresholds of seismic and infrasonic RMS. Finally, we also calculated the cross correlation function between seismic and infrasonic signals, which showed that the wave types causing such seismo-acoustic relationship are mainly incident seismic and infrasonic waves, likely with a common source.351 780 - PublicationRestrictedTracking eruptive phenomena by infrasound: May 13, 2008 eruption at Mt. Etna(2009-03-12)
; ; ; ; ; ;Cannata, A.; Dipartimento di Scienze Geologiche, Università di Catania ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Privitera, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Russo, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Gresta, S.; Dipartimento di Scienze Geologiche, Università di Catania; ; ; ; Active volcanoes produce inaudible infrasound due to the coupling between surface magmatic processes and the atmosphere. Monitoring techniques based on infrasound measurements have been proved capable of producing information during volcanic crises. We report observations collected from an infrasound network on Mt. Etna which enabled us to detect and locate a new summit eruption on May 13, 2008 when poor weather inhibited direct observations. Three families of signals were identified that allowed the evolution of the eruption to be accurately tracked in real-time. Each family is representative of a different active vent, producing different waveforms due to their varying geometry. Several competitive models have been developed to explain the source mechanisms of the infrasonic events, but according to our studies we demonstrate that two source models coexist at Mt. Etna during the investigated period. Such a monitoring system represents a breakthrough in the ability to monitor and understand volcanic phenomena.193 22 - PublicationOpen AccessAlgoritmi di Change Point Analysis delle serie temporali: il tremore vulcanico registrato sul vulcano Etna come caso di studio(2016-02-22)
; ; ; ; ; ; ;Cassisi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Fiumara, S.; Università degli Studi di Messina (D.I.C.I.E.A.M.A.) ;Cannata, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Aliotta, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Scarpa, M.; Università degli Studi di Messina (D.I.C.I.E.A.M.A.); ; ; ; ; 281 401 - PublicationRestrictedRelationship between soil CO2 flux and volcanic tremor at Mt. Etna: Implications for magma dynamics(2010-08)
; ; ; ; ; ; ; ; ; ;Cannata, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Giudice, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Gurrieri, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Montalto, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Alparone, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Di Grazia, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Gresta, S.; Dipartimento di Scienze Geologiche, Universita` di Catania, Corso Italia 57, 95129 Catania, Italy ;Liuzzo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; ; ; ; ; ; Large variations of the CO2 flux through the soil were observed between November 2002 and January 2006 at Mt. Etna volcano. In many cases, the CO2 flux was strongly influenced by changes in air temperature and atmospheric pressure. A new filtering method was then developed to remove the atmospheric influences on soil CO2 flux and, at the same time, to highlight the variations strictly related to volcanic activity. Successively, the CO2 corrected data were quantitatively compared with the spectral amplitude of the volcanic tremor by cross correlation function, cross-wavelet spectrum and wavelet coherence. These analyses suggested that the soil CO2 flux variations preceded those of volcanic tremor by about 50 days. Given that volcanic tremor is linked to the shallow (a few kilometer) magma dynamics and soil CO2 flux related to the deeper (*12 km b.s.l.) magma dynamics, the ‘‘delayed similarity’’ between the CO2 flux and the volcanic tremor amplitude was used to assess the average speed in the magma uprising into the crust, as about 170–260 mper day. Finally, the large amount of CO2 released before the onset of the 2004–2005 eruption indicated a deep ingression of new magma, which might have triggered such an eruption.283 30