http://hdl.handle.net/2122/281 2013-06-18T07:38:07Z http://hdl.handle.net/2122/8662 Title: The Volcano-Seismic Clock of the South American Pacific Margin - A Possible First Link Between Natural Disasters Prevention and Expanding Earth Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Abstract: A volcano-seismic correlation was for a long time suspected to occur on the Pacific margin of South America. Scalera (2008) using the data available in 2006 in the Smithsonian Institution Catalogue of the volcanic eruptions, has revealed evidence that earthquakes happened into the South-American Wadati-Benio zone – with magnitude greater than 8.4 –are associated to an enhanced rate of volcanic eruptions, but has been impossible to determine the causal chain between the two phenomena. After 2006, the effort of the Smithsonian Institution to improve our knowledge of this region has resulted in a greatly increased completeness of the catalogue, adding the new eruptions for the 2000- 2010 interval, but also an additional 50% of new entries in the list of the Andean volcanoes. The occurrence of the Chilean earthquake of Maule – 27 February 2010 (M=8.8); occurred at five decades from the 1960 quake – has been the occasion to rework all the data searching for additional clues able to indicate a preferred causal direction eruptions-earthquakes or earthquakes-eruptions – or from a third more general cause (e.g. a mantle movements) to both eruptions and earthquakes. This short note discusses the three above-said hypotheses and tries to establish if these results could be useful to the aims of the Civil Protection in the programs of prevention and/or forecasting of natural disasters. 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8609 Title: Enhanced crystal fabric analysis of a lava flow sample by neutron texture diffraction: A case study from the Castello d’Ischia dome Authors: Walter, J. M.; Mineralogisch-Petrologisches Institut, Universität Bonn, Poppelsdorfer Schloss, D-53115, Bonn,; Iezzi, G.; Dipartimento di Ingegneria e Geologia (INGEO), Università G. d’Annunzio, Chieti, Italy; Albertini, G.; Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Università Politecnica delle Marche,; Gunther, M. E.; Department of Geological Sciences, University of Idaho, Moscow, Idaho, USA; Piochi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Ventura, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Jansen, E.; Mineralogisch-Petrologisches Institut, Universität Bonn, Bonn, Germany; Fiori, F.; Di.S.C.O., Sez. di Biochimica, Biologia e Fisica, Università Politecnica delle Marce, Ancona, Italy Abstract: The crystal fabric of a lava has been analyzed for the first time by neutron texture diffraction. In this study we quantitatively investigate the crystallographic preferred orientation of feldspars in the Castello d’Ischia (Ischia Island, Italy) trachytic exogenous dome. The crystallographic preferred orientation was measured with the monochromatic neutron texture diffractometer SV7 at the Forschungszentrum Jülich in Germany and a Rietveld refinement was applied to the sum diffraction pattern. The complementary thin section analysis showed that the three-dimensional crystal shape and the corresponding shape preferred orientation are in agreement with the quantitative orientation distributions of the neutron texture data. The (0k0) crystallographic planes of the feldspars are roughly parallel to the local flow bands, whereas the other corresponding pole figures show that a pivotal rotation of the anorthoclase and sanidine crystals was active during the emplacement of this lava dome. In combination with scanning electron microscopy investigations, electron probe microanalysis, XRF, and X-ray diffraction, the Rietveld refinement of the neutron diffraction data indicates a slow cooling dynamic on the order of several months during their crystallization under subaerial conditions. Results attained here demonstrate that neutron texture diffraction is a powerful tool that can be applied to lava flows. 2013-01-30T23:00:00Z http://hdl.handle.net/2122/8341 Title: Reply to comment by D. Carbone and D. Patanè on “Multi-disciplinary investigation on a lava fountain preceding a flank eruption: the 10 May 2008 Etna case” Authors: Bonaccorso, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Cannata, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Corsaro, R. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Di Grazia, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Gambino, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Greco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Miraglia, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Pistorio, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia Abstract: Bonaccorso et al. [2011a] investigated the source and magma dynamics of the 10 May 2008 lava fountain at the South-East Crater (SEC) of Mount Etna through a multidisciplinary approach that integrated a wide data set ranging from bulk rock compositions of the erupted products to seismic tremor and long-period events, tilt and gravity signals. Using a large dataset, the study provided a robust framework in which the mechanism of the 10 May 2008 lava fountain is explained as a violent release of bubble-rich magma layer previously trapped at the top of a shallow reservoir located between −0.5 and 1.5 km above sea level (asl). This result is in agreement with recent relevant literature [Allard et al., 2005; Vergniolle and Ripepe, 2008; Aiuppa et al., 2010; Andronico and Corsaro, 2011; Bonaccorso et al., 2011b; Calvari et al., 2011; Vergniolle and Gaudemer, 2012]. In the introduction of their comment Carbone and Patanè [submitted] affirm that in their opinion the interpretation that “the lava fountain was generated by the fragmentation of a foam layer trapped at the top of shallow reservoir” is not soundly based. This comment’s conclusion is puzzling because one of the comment’s authors (D. Patanè) is also a co-author on the paper by Aiuppa et al. [2010] where the same conclusion, now criticized, was well supported (see figure 5 and conclusions of that paper). In particular, in the conclusions Aiuppa et al. [2010] reported that “The paroxysmal SEC episodes mark the violent release of a bubble-rich magma layer, with bubbles having relatively shallow reservoir ...", that is, the same conclusion now criticized in the comment. After this, the comment raises issues concerning the analysis and interpretation of gravity and tilt data in the multidisciplinary approach presented by Bonaccorso et al. [2011a]. The comment by Carbone and Patanè is divided into 4 paragraphs, labelled “1. Introduction”, “2. Gravity changes”, “3. Tilt changes” and “4. Concluding remarks” with only paragraphs 2 and 3 containing specific comments. In this reply, we address these two paragraphs, and we shall show how the assumptions underlying the comment are merely speculative and why the results presented by Bonaccorso et al.[2011a] remain valid. 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8327 Title: Comment on "Multidisciplinary investigation on a lava fountain preceding a flank eruption: The 10 May 2008 Etna case" by A. Bonaccorso et al. Authors: Carbone, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Patanè, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia Abstract: The paper "Multidisciplinary investigation on a lava fountain preceding a flank eruption: The 10 May 2008 Etna case", by Bonaccorso et al. (2011), presents a multi-parameter dataset encompassing the eruptive episode featured in the title. Through the dataset at their disposal, the authors tried to set constraints on the coupled phenomena which governed the paroxysmal event and subsequent flank eruption. Even though the joint analysis of different data offers considerable potential to extract additional information on the dynamics behind the observed phenomena, the most obvious implication is the risk of not treating all the available information with due care, which may lead to misinterpretation of the data. In the following, we discuss issues concerning the analysis and interpretation of gravity and tilt data in Bonaccorso et al. (2011) and show why, in our opinion, the conclusion that "all the data concur in indicating that the 10 May lava fountain was generated by the fragmentation of a foam layer trapped at the top of a shallow reservoir" is not soundly based. 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8109 Title: Geological events during the Holocene: an overview for Northern Europe and the Mediterranean Authors: Peppoloni, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; Di Capua, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia Abstract: The Holocene is the most recent geological epoch spanning from about 11700 years ago to the present day. The most important human civilizations appeared during the Holocene. From the Holocene onwards, environmental changes, and the hazards associated with them, became extremely important for their impact on historical events, in some cases blending with humanity’s vicissitudes and influencing the rise and decline of civilizations. This paper summarises the geological and climatic conditions of Northern Europe during the Holocene and tries to determine whether or not they support the hypothesis formulated by Felice Vinci (Vinci, 2003) about the migration of Baltic populations towards the Mediterranean in the Bronze Age at the end of the “climatic optimum” (Houghton et al., 1990; Rohling & De Rijk, 1999). This study presents data on glacio-eustatic changes and on isostatic uplift together with information on probable tsunamis that occurred in the North Atlantic, North Sea, Scandinavia and the Baltic Sea. Moreover, some data on catastrophic events that affected the Mediterranean region are reported, because these catastrophes could have favoured the settlement of “people coming from the sea” that took advantage of the demographic and socio-economic weakening of indigenous populations (Driessen, 2002). The paper aims to provide geological and palaeogeographic constraints to the hypotheses formulated by Felice Vinci on the migration of Scandinavians towards the Mediterranean. The data analysed have been collected from the available scientific literature (see references). The amount of information available for each geological phenomenon is vast and sometimes theories developed from the same data are in conflict. The comparison between the Mediterranean and the Baltic areas (one of which could have been the theatre of the Homeric events) will be useful to find evidence of geological phenomena within the Homeric texts, giving useful indications to better understand where the poems are set or at least to provide interesting discussion points related to Felice Vinci’s hypothesis (Vinci 2003). 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8079 Title: Spatial vent opening probability map of Etna volcano (Sicily, Italy) Authors: Cappello, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Acocella, V.; Dipartimento di Scienze Geologiche, Università RomaTre, Rome, Italy; Gallo, G.; Dipartimento di Matematica e Informatica, Università di Catania, Catania, Italy; Vicari, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Del Negro, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia Abstract: We produce a spatial probability map of vent opening (susceptibility map) at Etna, using a statistical analysis of structural features of flank eruptions of the last 2 ky. We exploit a detailed knowledge of the volcano structures, including the modalities of shallow magma transfer deriving from dike and dike-fed fissure eruptions analysis on historical eruptions. Assuming the location of future vents will have the same causal factors as the past eruptions, we converted the geological and structural data in distinct and weighted probability density functions, which were included in a non-homogeneous Poisson process to obtain the susceptibility map. The highest probability of new eruptive vents opening falls within a N-S aligned area passing through the Summit Craters down to about 2,000 ma.s.l. on the southern flank. Other zones of high probability follow the North-East, East-North-East, West, and South Rifts, the latter reaching low altitudes (∼400 m). Less susceptible areas are found around the faults cutting the upper portions of Etna, including the western portion of the Pernicana fault and the northern extent of the Ragalna fault. This structuralbased susceptibility map is a crucial step in forecasting lava flow hazards at Etna, providing a support tool for decision makers. 2012-09-01T22:00:00Z http://hdl.handle.net/2122/8009 Title: Paleomagnetic secular variation at the Azores during the last 3 ka Authors: Di Chiara, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Speranza, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Porreca, M.; Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Ponta Delgada, Portugal. Abstract: We report on 33 new paleomagnetic directions obtained from 16 lava flows emplaced in the last 3 ka on São Miguel, the largest island of the Azores. The data provide 27 well-dated directions from historical or 14C dated flows which, together with 6 directions previously gathered from the same flows by Johnson et al. (1998), yield the first paleomagnetic directional record of the last 3 ka from the Atlantic Ocean. Within-flow directions are consistent, suggesting that inclination swings from 60 to 25 and declination changes between 10 to 20 reflect variations in the geomagnetic field over the last 3 ka. To a first approximation, the declination record is consistent with predictions from CALS3k.4 and gufm1 global field models. Conversely, inclination values are lower than model predictions at two different ages: 1) four sites from the 1652 AD flow yield I = 48 instead of I = 63 predicted by gufm1; 2) data from several flows nicely mimic the inclination minimum of 800–1400 AD, but inclination values are lower by 10 than CALS3k.4 model predictions. By interpolating a cubic spline fit on declination / inclination versus age data, we tentatively infer the directional evolution of the geomagnetic field at the Azores from 1000 BC to 1600 AD. The obtained curve shows three tracks in virtual overlap during the 1000–800 BC, 800–500 BC, and 400–700 AD time spans. 2012-07-11T22:00:00Z http://hdl.handle.net/2122/7871 Title: GPS ground deformation patterns at Mount St. Helens (Washington, USA) from 2004 to 2010 Authors: Palano, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Guarrera, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Mattia, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia Abstract: GPS measurements on Mount St. Helens spanning the 2004.00-2010.85 time interval, encompassing the 2004-2008 dome-building eruption, were analyzed. First, a local reference frame was derived in order to isolate the volcanic ground deformation from the background tectonic pattern related to the interactions between the Pacific, Juan de Fuca and North American plates. Secondly, the resulting ground deformation patterns were modelled to constrain magmatic sources. Results suggest a vertically elongated magma chamber centred at 8 - 9 km depth beneath the summit area that deflated during the beginning of the dome growth and inflated since January 2008, evidencing that a primary magma reservoir was active both during and after the eruption in a magmatic system persistent over the time. 2012-03-31T22:00:00Z http://hdl.handle.net/2122/7861 Title: The case of the 1981 eruption of Mount Etna: An example of very fast moving lava flows Authors: Coltelli, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Marsella, M.; Dipartimento di Ingegneria Civile Edile e Ambientale, Sapienza Università di Roma, Rome I‐00184, Italy; Proietti, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Scifoni, S.; Dipartimento di Ingegneria Civile Edile e Ambientale, Sapienza Università di Roma, Rome I‐00184, Italy (silvia.scifoni@uniroma1.it) Abstract: Mount Etna despite being an extremely active volcano which, during the last 400 years, has produced many lava flow flank eruptions has rarely threatened or damaged populated areas. The reconstruction of the temporal evolution of potentially hazardous flank eruptions represents a useful contribution to reducing the impact of future eruptions by and analyzing actions to be taken for protecting sensitive areas. In this work, we quantitatively reconstructed the evolution of the 1981 lava flow field of Mt Etna, which threatened the town of Randazzo. This reconstruction was used to evaluate the cumulated volume, the time averaged discharge rate trend and to estimate its maximum value. The analysis was conducted by comparing pre‐ and post‐eruption topographic surfaces, extracted by processing historical photogrammetric data sets and by utilizing the eruption chronology to establish the lava flow front positions at different times. An unusually high discharge rate (for Etna) of 640 m3/s was obtained, which corresponds well with the very fast advance rate observed for the main lava flow. A comparison with other volcanoes, presenting high discharge rate, was proposed for finding a clue to unveil the 1981 Etna eruptive mechanism. A model was presented to explain the high discharge rate, which includes an additional contribution to the lava discharge caused by the interception of a shallow magma reservoir by a dike rising from depth and the subsequent emptying of the reservoir. 2011-12-31T23:00:00Z http://hdl.handle.net/2122/7859 Title: Sistema di monitoraggio e pubblicazione dei dati delle recenti crisi eruttive dell’Etna e dello Stromboli (2002 – 2003) Authors: D’Agostino, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; La Via, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Mangiagli, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Piccione, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Reitano, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Torrisi, O.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia Abstract: Nell’ambito delle recenti crisi eruttive e sismiche del 2002 e 2003 la Sala Operativa della Sezione di Catania dell’Istituto Nazionale di Geofisica e Vulcanologia ha immediatamente intensificato tutte le attività scientifiche e tecnologiche al fine di sovrintendere al monitoraggio e sorveglianza delle aree interessate dai complessi fenomeni in corso. Tutti i dati acquisiti dalle stazioni remote e pre-elaborati dalle unità funzionali tematiche sono concentrati in un'unica banca dati generale che, nel caso specifico di eventi calamitosi come quelli occorsi, diventa strumento di studio e di immediata fruizione non solo per il personale afferente alle varie discipline, ma anche per gli enti preposti. Pertanto sono stati implementati dei sistemi di monitoraggio e diffusione dei dati on-line realizzati in funzione delle esigenze manifestate durante tali attività. In particolare sono stati realizzati, in collaborazione con i colleghi delle altre Unità Funzionali e delle altre Sezioni, dei collegamenti infrastrutturali tra le sedi interessate ed i siti monitorati, al fine di rendere più agevole e sicuro il trasferimento dei dati acquisiti dalle stazioni remote. L’esperienza acquisita durante la recente eruzione di Stromboli e la precedente dell’Etna, ha suggerito la realizzazione di sistemi automatici per la compilazione e la pubblicazione dei comunicati giornalieri, nonché la divulgazione in tempo quasi reale di tutte le informazioni ritenute rilevanti per la comprensione dei fenomeni in corso. Poiché la grandissima quantità di dati poco si presta ad essere trattata solo in forma cartacea, e vista l’enorme richiesta da parte degli organismi accreditati e degli organi di stampa, si è deciso di approntare un sito web che descrivesse, in maniera semplice, ma con rigore scientifico, le attività ed i risultati dell’istituto. Allo scopo, in sole ventisei ore il personale della Unità Funzionale Sala Operativa ha allestito un completo sito Web, all’interno del Web generale della Sezione di Catania, che descrive tutte le attività e riporta in tempo quasi reale i risultati ottenuti dalle elaborazioni degli esperti ed i dati ritenuti significativi. Il carattere grafico e la facile consultazione del sito, consentono di avere informazioni a tutto campo, avvalendosi dell’ausilio di grafici, mappe, foto, rapporti estesi, risultati di elaborazioni e quant’altro sia ritenuto utile ai fini divulgativi e di informazione. 2003-06-08T22:00:00Z