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Ferrera, Elisabetta
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Ferrera, Elisabetta
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- PublicationRestrictedActive faults on the eastern flank of Etna volcano (Italy) monitored through soil radon measurements(European Geosciences Union, 2012-04)
; ; ; ; ; ;Neri, Marco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Giammanco, Salvatore; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Ferrera, Elisabetta; Università degli Studi di Catania, Dip. Scienze della Terra ;Patanè, Giuseppe; Università degli Studi di Catania, Dip. Scienze della Terra ;Zanon, Vittorio; Centro de Vulcanologia e Avaliação de Riscos Geológicos - Universidade dos Açores; ; ; ; This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the unstable eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. In particular, the highest anomalies were found at the intersection between WNW-ESE and NW-SE -running faults. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. These maps revealed a progressive deepening of hypocenters from NW to SE, with the exception of a narrow zone in the central part of the area, with a roughly WNW-ESE direction. Also, the highest values of seismic energy were released during events in the southern and northwestern sectors of the area. Both radon and thoron anomalies were located in areas affected by relatively deep (5-10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquake depth and intensity can give some hints on the source of gas and/or on fault dynamics. Lastly, an important spin-off of this study is the recognition of some areas where radon activity was so high (>50000 Bq/m3) that it may represent a potential hazard to the local population. In fact, radon is the leading cause of lung cancer after cigarette smoke for long exposures and, due to its molecular weight, it accumulates in underground rooms or in low ground, particularly where air circulation is low or absent. In the investigated area this risk is real, as it is inhabited by thousands of people who reside there all year long. Therefore, this study serves as a starting point for the assessment of radon hazard in the Mt. Etna area, considering both spatial and temporal changes in soil radon emissions depending on the presence of faults and/or the occurrence of seismic activity.189 14 - PublicationRestrictedSoil radon measurements as a potential tracer of tectonic and volcanic activity(2016-04-15)
; ; ; ; ; ; ; ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Ferrera, E.; Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania ;Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Currenti, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cirrincione, R.; Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania ;Patanè, G.; Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania ;Zanon, V.; Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Ponta Delgada, Portugal; ; ; ; ; ; In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009–2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of <1400 m, with an ascent speed of >50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.705 6 - PublicationRestrictedSpatial distribution of soil radon as a tool to recognize active faulting on an active volcano: the example of Mt. Etna (Italy)(2011-06-25)
; ; ; ; ; ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Ferrera, E.; Università degli Studi di Catania, Dip. Scienze della Terra, Corso Italia, 52 e 95129 Catania, Italy ;Patanè, G.; Università degli Studi di Catania, Dip. Scienze della Terra, Corso Italia, 52 e 95129 Catania, Italy ;Zanon, V.; Centro de Vulcanologia e Avaliação de Riscos Geológicos e Universidade dos Açores, Rua Mãe de Deus, 9501-801 Ponta Delgada, Portugal; ; ; ; This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. Both radon and thoron anomalies were located in areas affected by relatively deep (5e10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquakes depth and intensity can give some hints on the source of gas and/or on fault dynamics.530 89 - PublicationOpen AccessDetection of volcano unrest from multiparameter pattern classification(2015-06)
; ; ; ; ; ; ; ;Falsaperla, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Langer, H.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Spampinato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Di Grazia, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Messina, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Ferrera, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; ; ; Short-term forecasting of volcanic unrest requires high-rate/continuous data acquisition and monitoring of multidisciplinary data. Volcano Observatories worldwide usually adopt various tools for the automatic processing of geophysical and geochemical data streams to detect changes heralding impending eruptive activity. Here we discuss the application to multivariate data sets of a free software named KKAnalysis. The software is one of the data mining tools of the European MEDiterrranean Supersite Volcanoes (MEDSUV) project, and carries out the pattern classification of data of whatever nature provided in numerical format. We explain how this software works combining Self-Organizing Maps and fuzzy clustering. Beside numerical log files, changes of pattern characteristics are visualized as output of KKAnalysis in graphical form, by creating a sequence of colored symbols. This convenient color code highlights the development in time of the characteristics of whatever multidimensional feature vector. We also present results of applications to seismic data (volcanic tremor), in-soil radon activity, and ambient parameters (barometric pressure and air temperature measurements acquired at the same site of the radon data). We explore these applications at Mt. Etna, Italy, in time spans of various duration (from months to years), in which eruptive activity ranged from short-lived (usually from tens of minutes to hours) lava fountains to long-lasting (from months to years) lava effusions.211 103 - PublicationOpen AccessUn metodo per riconoscere faglie attive sepolte mediante misure areali di radon dal suolo(2014-04)
; ; ; ; ; ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Ferrera, E.; Università degli Studi di Catania, Dipartimento di Scienze della Terra, Catania ;Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Patanè, G.; Università degli Studi di Catania, Dipartimento di Scienze della Terra, Catania ;Zanon, V.; Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Ponta Delgada, Portogallo; ; ; ; Lo studio riassume i risultati di una campagna di misure geochimiche e strutturali condotte nel 2004 (Neri et al., 2011) e riguarda la misurazione delle emissioni di gas radon e thoron dal suolo effettuate lungo il fianco orientale dell’Etna, in una zona caratterizzata dalla presenza di numerose faglie attive. Le elaborazioni statistiche effettuate hanno permesso di riconoscere soglie di anomalia dei dati geochimici, nonché la produzione di mappe di distribuzione che hanno evidenziato una significativa correlazione spaziale tra le anomalie riscontrate e i principali lineamenti tettonici. Entrambe le anomalie di radon e thoron si trovavano in aree interessate da sismicità relativamente profonda, in particolare in corrispondenza delle zone di intersezione tra faglie differentemente orientate. Questo studio conferma che la mappatura della distribuzione di gas radon e thoron dal suolo può rivelare la presenza di faglie nascoste da coperture recenti, o faglie che non sono chiaramente visibili in superficie.223 471