http://hdl.handle.net/2122/201 Ricerca nel canale cerca http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/6035 Titolo: Insights into fluid circulation across the Pernicana Fault (Mt. Etna, Italy) and implications for flank instability<br/><br/>Autori: Siniscalchi, A.; Dipartimento di Geologia e Geofisica, Università degli Studi di Bari, via Orabona, 4-70125, Bari-Italy; Tripaldi, S.; Dipartimento di Geologia e Geofisica, Università degli Studi di Bari, via Orabona, 4-70125, Bari-Italy; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Piscitelli, S.; Istituto di Metodologie per l' Analisi Ambientale, CNR, Tito (PZ), Italy; Balasco, M.; Istituto di Metodologie per l' Analisi Ambientale, CNR, Tito (PZ), Italy; Behncke, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Magri, C.; Dipartimento di Geologia e Geofisica, Università degli Studi di Bari, via Orabona, 4-70125, Bari-Italy; Naudet, V.; Université Bordeaux 1, Geosciences Hydrosciences Material and Constructions, GHYMAC-EA 4134, Talence, F-33405, France; Rizzo, E.; Istituto di Metodologie per l' Analisi Ambientale, CNR, Tito (PZ), Italy<br/><br/>Abstract: We conducted geophysical–geochemical measurements on a ∼2 kmN–S profile cutting across the PernicanaFault, one of the most active tectonic features on the NE flank of Mt. Etna. The profile passes from theunstable E flank of the volcano (to the south) to the stable N flank and significant fluctuations in electricalresistivity, self-potential, and soil gas emissions (CO2, Rn and Th) are found. The detailed multidisciplinaryanalysis reveals a complex interplay between the structural setting, uprising hydrothermal fluids, meteoricfluids percolating downwards, ground permeability, and surface topography. In particular, the recoveredfluid circulation model highlights that the southern sector is heavily fractured and faulted, allowing theformation of convective hydrothermal cells. Although the existence of a hydrothermal system in a volcanicarea does not surprise, these results have great implications in terms of flank dynamics at Mt. Etna. Indeed,the hydrothermal activity, interacting with the Pernicana Fault activity, could enhance the flank instability.Our approach should be further extended along the full extent of the boundary between the stable andunstable sectors of Etna for a better evaluation of the geohazard in this active tectonic area. http://hdl.handle.net/2122/5381 Titolo: Motivations for muon radiography of active volcanoes<br/><br/>Autori: Macedonio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Martini, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia<br/><br/>Abstract: Muon radiography represents an innovative tool for investigating the interior of active volcanoes. This methodintegrates the conventional geophysical techniques and provides an independent way to estimate the density ofthe volcano structure and reveal the presence of magma conduits. The experience from the pioneer experimentsperformed at Mt. Asama, Mt. West Iwate, and Showa-Shinzan (Japan) are very encouraging. Muon radiographycould be applied, in principle, at any stratovolcano. Here we focus our attention on Vesuvius and Stromboli(Italy). http://hdl.handle.net/2122/5141 Titolo: Spectral properties of volcanic materials from hyperspectral field and satellite data compared with LiDAR data at Mt. Etna<br/><br/>Autori: Spinetti, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Casacchia, R.; CNR, Dipartimento Terra & Ambiente, Rome, Italy; Colini, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Behncke, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Salvatori, R.; CNR, Ist Inquinamento Atmosfer, Rome, Italy; Buongiorno, M. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Pareschi, M. T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia<br/><br/>Abstract: Spectral properties of volcanic materials in the optical region (350–2500 nm) of the electromagnetic spectrum are analyzed. The goal is to characterize air-fall deposits, recent lava flows, and old lava flows based on their spectral reflectance properties and on the textural characteristics (grain size) of pyroclastic deposits at an active basaltic volcano. Data were acquired during a spectroradiometric field survey at Mt. Etna (Italy) in summer 2003 and combined with hyperspectral satellite (Hyperion) and airborne LiDAR (Light Detection and Ranging) data. In addition, air-fall deposits produced by the highly explosive 2002–2003 eruption have been sampled and spectrally characterized at different distances from the new vents. The spectral analysis shows that air-fall deposits are characterized by low reflectance values besides variations in grain size. This distinguishes them from other surface materials. Old lava flows show highest reflectance values due to weathering and vegetation cover. The spectral data set derived from the field survey has been compared to corrected satellite hyperspectral data in order to investigate the Hyperion capabilities to differentiate the surface cover using the reflectance properties. This has allowed us to identify the 2002–2003 air-fall deposits in a thematic image just few months after their emplacement. Moreover, the observed differences in the field spectra of volcanic surfaces have been compared with differences in the signal intensity detected by airborne LiDAR survey showing the possibility to include information on the texture of volcanic surfaces at Mt. Etna. The approach presented here may be particularly useful for remote and inaccessible volcanic areas and also represents a potentially powerful tool for the exploration of extraterrestrial volcanic surfaces. http://hdl.handle.net/2122/5140 Titolo: LiDAR-based digital terrain analysis of an area exposed to the risk of lava flow invasion: the Zafferana Etnea territory, Mt. Etna (Italy)<br/><br/>Autori: Bisson, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Behncke, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Fornaciai, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia<br/><br/>Abstract: The town of Zafferana Etnea, located on the southeastern slope of Mt. Etna volcano (Italy), has been repeatedly threatened by lava flows in recent centuries. The last serious threat occurred during the 1991–1993 eruption, when the lava front came to a halt only 1.7 km from the centre of town. Morphostructural data derived from light detection and ranging (LiDAR) surveys carried out on Etna in 2005 have enabled us to evaluate the risk of lava invasion in a section (16 km2) of the Zafferana Etnea territory. Qualitative and quantitative results are obtained combining the information derived from LiDAR analysis with geological, morphological and structural data using geographic information systems technology (GIS). The study quantifies in unprecedented detail the areal extent and volume of forested and urban areas and its degree of exposure to different levels of hazard from future lava invasion. Nearly 52% of the urban texture fall into areas of moderate to high risk from lava invasion. Future land use planning should take these findings into account and promote new development preferentially in areas of lower risk. http://hdl.handle.net/2122/4912 Titolo: Comparison between different methodologies for detecting Radon in soil along an active fault: the case of the Pernicana fault system, Mt. Etna (Italy)<br/><br/>Autori: Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Immè, G.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Mangano, G.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Morelli, D.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia<br/><br/>Abstract: Three different methodologies were used to measure Radon (222Rn) in soil, based on both passive and active detection system. The first technique consisted of Solid State Nuclear Track Detectors (SSNTD), CR-39 type, and allowed integrated measurements. The second one consisted of a portable device for short time measurements. The last consisted of a continuous measurement device for extended monitoring, placed in selected sites. Soil 222Rn activity was measured together with soil Thoron (220Rn) and soil carbon dioxide (CO2) efflux, and it was compared with the content of radionuclides in the rocks. Two different soil gas horizontal transects were investigated across the Pernicana fault system (NE flank of Mount Etna), from November 2006 to April 2007. The results obtained with the three methodologies are in a general agreement with each other and reflect the tectonic settings of the investigated study area. The lowest 222Rn values were recorded just on the fault plane, and relatively higher values were recorded a few tens of meters from the fault axis on both of its sides. This pattern could be explained as a dilution effect resulting from high rates of soil CO2 efflux. Time variations of 222Rn activity were mostly linked to atmospheric influences, whereas no significant correlation with the volcanic activity was observed. In order to further investigate regional radon distributions, spot measurements were made to identify sites having high Rn emissions that could subsequently be monitored for temporal radon variations.. SSNTD measurements allow for extended-duration monitoring of a relatively large number of sites, although with some loss of temporal resolution due to their long integration time. Continuous monitoring probes are optimal for detailed time monitoring, but because of their expense, they can best be used to complement the information acquired with SSNTD in a network of monitored sites.. http://hdl.handle.net/2122/4880 Titolo: Analyzing Virtual Reference Station for GPS surveying: experiments and applications in a test site of the northern Apennine (Italy).<br/><br/>Autori: Pesci, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Loddo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Teza, G.; Università di Padova, Dipartimento di Geoscienze, Padova, Italia; Cenni, N.; Università di Bologna, Dipartimento di Fisica, Settore Geofisica, Bologna, Italia; Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia<br/><br/>Abstract: The availability of a GPS network of 10-20 km mean size, provides good topographical support for the measurement of ground displacements, even at a local scale such as a landslide. In particular, a series of multitemporal kinematic or rapid-static GPS acquisitions of a landslide allows a good characterization of its displacements if the measurements are referred to a GPS reference network. Nevertheless, a wider network formed by stations located at long distances, for example at several tens of kilometers, characterized by large spacing, can lead to results affected by high noise, degrading the accuracy of final point positions. In order to obtain an adequate GPS reference network, some virtual reference stations (VRSs) can be introduced, even if a network refinement based on VRS cannot reach the same accuracy of a real local network. Some experiments, including measurements on a real landslide, have been performed in order to evaluate the performance of this technique. The results point out that the standard deviation of the obtained solutions is about two or three times larger than those which can be reached using a real local network. http://hdl.handle.net/2122/4755 Titolo: GlobVolcano Project Overview<br/><br/>Autori: Borgström, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Seifert, F. M.; Science, Application and Future Technologies Department ESA/ESRIN, Frascati, Italy; Tampellini, L.; Application department Carlo Gavazzi Space S.p.A. Milan, Italy; Ratti, R.; Application department Carlo Gavazzi Space S.p.A. Milan, Italy<br/><br/>Abstract: The GlobVolcano project is part of the ESA DUEprogramme. The project aims at demonstrating EO-basedservices to support the Volcanological Observatories and othermandate users (e.g. Civil Protection authorities, scientificcommunities of volcanoes) in their monitoring activities.During the project a worldwide selection of user organizationswill cooperate with the GlobVolcano team in order to harmonizeuser’s requirements and to evaluate the EO-based services . The“Osservatorio Vesuviano” of Naples (INGV-Italy) coordinatesthe communications between the project and the UserCommunity. IPGP of Paris is responsible for the scientificcoordination and the validation activities.The project activities are split in two phases. During the firstphase (completed in June 2008) the service infrastructure andinterface to the users have been developed. Prototype EO-basedinformation products have been generated and validated. Serviceprovision on pre-operational basis will take place during thesecond phase. http://hdl.handle.net/2122/4751 Titolo: Volcanic Risk System (SRV): ASI Pilot Project to Support The Monitoring of Volcanic Risk In Italy by Means of EO Data<br/><br/>Autori: Buongiorno, M. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Musacchio, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Zoffoli, S.; Agenzia Spaziale Italia, Rome, Italy; Cardaci, C.; Dipartimento della Protezione Civile, Rome, Italy; Sansosti, E.; CNR- Istituto per il Rilevamento Elettromagnetico dell’Ambiente Naples, Italy; Vignoli, S.; Advanced Computer System S.p.A., Rome, Italy; Amodio, A.; Galileian Plus S.r.L., Rome, Italy; Pugnaghi, S.; Università degli Studi di Modena e Reggio Emilia, Modena, Italy; Teggi, S.; Università degli Studi di Modena e Reggio Emilia, Modena, Italy; Puglisi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Borgstrom, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia<br/><br/>Abstract: The ASI-SRV(Sistema Rischio Vulcanico) projectstarted at the beginning of the 2007 is funded by the ItalianSpace Agency (ASI) in the frame of the National Space Plan2003-2005 under the Earth Observations section for naturalrisks management. Coordinated by the Istituto Nazionale diGeofisica e Vulcanologia (INGV), which is responsible at nationallevel for the volcanic monitoring, the project has as mainobjective to develop a pre-operative system based on EO dataand ground measurements integration to support the volcanicrisk monitoring of the Italian Civil Protection Department. Theproject philosophy is to implement specific modules which allowto process, store and visualize through Web GIS tools EO derivedparameters considering three activity phases: 1) knowledge andprevention; 2) crisis; 3) post crisis. In order to combineeffectively the EO data and the ground networks measurementsthe system will implement a multi-parametric analysis tool,which represents and unique tool to analyze contemporaneouslya large data set of data in “near real time”. The SRV project willbe tested his operational capabilities on three Italian Volcanoes:Etna,Vesuvio and Campi Flegrei. http://hdl.handle.net/2122/4497 Titolo: A LIDAR survey of Stromboli volcano (Italy): DEM-based geomorphology and intensity analysis<br/><br/>Autori: Fornaciai, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Bisson, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Landi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Pareschi, M. T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia<br/><br/>Abstract: LIDAR (Light Detection and Ranging) is a novel and very useful activeremote sensing system which can be used to directly identify geomorphological featuresas well as the properties of materials on the ground surface. In this work LIDAR datawas applied to the study of Stromboli volcano (Italy). LIDAR data points, collectedduring a survey in October 2005, were used to generate a Digital Elevation Model(DEM) and a calibrated intensity map of the ground surface. The DEM, derived mapsand topographic cross-sections were used to complete a geomorphological analysis ofStromboli that led to the identification of four main geomorphological domains linkedto major volcanic cycles. Moreover, we investigated and documented the potential ofLIDAR intensity data for distinguishing and characterizing different volcanic productssuch as fallout deposits, epiclastic sediments and lava flows. http://hdl.handle.net/2122/4155 Titolo: Volumetric observations during paroxysmal eruptions at Mount Etna: pressurized drainage of a shallow chamber or pulsed supply?<br/><br/>Autori: Harris, A. J. L.; HIGP/SOEST, University of Hawaii, 2525 Correa Road, Honolulu, HI 96822, USA; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia<br/><br/>Abstract: The October 17 to November 5, 1999, eruption of Mount Etna’s Bocca Nuova crater emplaced a V15U106 m3flow field. The eruption was characterized by 11 paroxysmal events during which intense Strombolian and lavafountain activity fed vigorous channelized PaPa flows at eruption rates of up to 120 m3 s31. Each paroxysm lastedbetween 75 and 450 min, and was separated by periods of less intense Strombolian activity and less vigorous (610 m3s31) effusion. Ground-based, satellite- and model-derived volumetric data show that the eruption was characterized bytwo periods during which eruption rates and cumulative volume showed exponential decay. This is consistent with ascenario whereby the system was depressurized during the first eruptive period (October 17^23), repressurized duringan October 24 pause, and then depressurized again during the second period (October 25^28). The imbalance betweenthe erupted and supplied volumes mean that the two periods involved the collection of 1.5^5.7U106 m3 and 1.2^3.6U106 m3, respectively, or an increase in the time-averaged supply to 11.6^13.6 m3 s31 and 12.5^14.9 m3 s31. Twomodels are consistent with the observed episodic fountaining, derived volumetric trends and calculated volumeimbalance: a magma collection model and a pulsed supply model. In the former case, depressurization of a shallowreservoir cause the observed volumetric trends and foam collapse at the reservoir roof powers fountaining. In thepulsing case, variations in magma flux account for pressurization^depressurization and supply the excess volume.Increases in rise rate and volatile flux, coupled with rapid exsolution during ascent, trigger fountaining. Limitingequations that define critical foam layer volumes and magma rise rates necessary for Hawaiian-style fountaining favorthe latter model.