http://hdl.handle.net/2122/296 Wed, 22 May 2013 18:08:50 GMT 2013-05-22T18:08:50Z http://hdl.handle.net/2122/8442 Title: A rapid method to assess fire-related debris flow hazard in the Mediterranean region: An example from Sicily (southern Italy) Authors: Bisson, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Favalli, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Fornaciai, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Isola, I.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Zanchetta, G.; Dipartimento di Scienze della Terra, University of Pisa, Pisa, Italy; Pareschi, M. T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia Abstract: Increased atmospheric temperatures during the high-pressure which characterise the Mediterranean climate in the dry summer time, coupled with an increase in the intensity of storms in the following wet season over recent years, increase the risk of summer fires as well as debris flows and floods in the autumn and/or in the following years. In addition, the diffuse urbanization of Italy requires a rapid and reliable tool be available in order to obtain preliminary information, at the end of the summer season, that identifies newly fired areas that present a significant hazard to human populations. In such burned zones, soil instability may be more severe favouring debris flows which may impact on populated zones. Thus, in this paper we discuss a rapid methodology to: (i) identify burned areas using band ratio's using multitemporal LANDSAT ETM images; (ii) evaluate the potential of the burned areas as the source of debris flows based on morphometric parameters (slope and hill slope curvature); (iii) evaluate the structures, such as houses and roads, exposed to potential damage by debris flows. Hazardous areas were evaluated using a stochastical model coupled with an empirical relationship which accounts for the mobility of the debris flows. The methodology provides a classification of the most “dangerous” burned areas and the potentially maximum inundated downslope areas. This has been applied to Sicily for the period autumn 2001–autumn 2002. The total burned area was 76.37 km2. According to the classification proposed 6.4% of the burned areas were consider of very high to high hazard potential, 54.4% of medium hazard and 43.2% of low hazard potential. Mon, 31 Oct 2005 23:00:00 GMT http://hdl.handle.net/2122/8442 2005-10-31T23:00:00Z http://hdl.handle.net/2122/8389 Title: Platinum levels in natural and urban soils from Rome and Latium (Italy): significance for pollution by automobile catalytic converter. Authors: Cinti, D.; aDipartimento di Scienze della Terra, Universita` ‘La Sapienza’, 00185 Rome, Italy; Angelone, M.; ENEA; Masi, U.; University of Rome "La Sapienza"; Cremisini, C. Abstract: Platinum concentrations in topsoil samples collected in 1992 (48) and in 2001 (16) from the urban area of Rome have been determined by ICP–MS.Concentrations in 47 soil samples collected in 1992 from natural sites of Latium (an area around Rome) have been determined for a first assessment of natural background levels.The Pt concentrations in Rome urban soils collected in 1992 range from 0.8 to 6.3 ngyg ( s3.8"1.0) overlapping the concentration range ¯X of natural soils from Latium ( s3.1"2.1 ngyg).No significant correlation has generally been found between Pt ¯X contents in the ‘natural’ soils and related bedrock or major pedogenetic parameters.These results suggest that there is no evidence of Pt pollution in Rome urban soils at that time, because the massive use of the automobile catalytic converter has only just started.Higher (up to six times more) Pt concentrations, than those measured in the 1992 samples, have been measured, in some cases, in Rome urban soils collected in 2001, suggesting a possible start of Pt accumulation because of the large-scale use in the last decade of automobile catalytic converters.At the same time, a clear decrease of lead levels in Rome urban soils with respect to the levels measured in 1992 has been observed, paralleling the decreasing number of lead gasoline-fuelled cars.Her e we present one of the first systematic studies for defining background levels of Pt in Italian natural soils, thus allowing for monitoring, in the future, should any possible Pt pollution caused by the use of automobile catalytic converter, especially in urban soils, occur. Mon, 31 Dec 2001 23:00:00 GMT http://hdl.handle.net/2122/8389 2001-12-31T23:00:00Z http://hdl.handle.net/2122/8228 Title: Tsunami risk assessments in Messina, Sicily – Italy Authors: Grezio, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Gasparini, P.; Università di Napoli - Federico II; Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Patera, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Tinti, S.; Università di Bologna Abstract: We present a first detailed tsunami risk assessment for the city of Messina where one of the most destructive tsunami inundations of the last centuries occurred in 1908. In the tsunami hazard evaluation, probabilities are calculated through a new general modular Bayesian tool for Probabil- ity Tsunami Hazard Assessment. The estimation of losses of persons and buildings takes into account data collected directly or supplied by: (i) the Italian National Institute of Statistics that provides information on the population, on buildings and on many relevant social aspects; (ii) the Italian National Territory Agency that provides updated economic values of the buildings on the basis of their typology (res- idential, commercial, industrial) and location (streets); and (iii) the Train and Port Authorities. For human beings, a fac- tor of time exposition is introduced and calculated in terms of hours per day in different places (private and public) and in terms of seasons, considering that some factors like the number of tourists can vary by one order of magnitude from January to August. Since the tsunami risk is a function of the run-up levels along the coast, a variable tsunami risk zone is defined as the area along the Messina coast where tsunami inundations may occur. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8228 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8225 Title: Probabilistic Tsunami Hazard Assessment for Messina Strait Area (Sicily, Italy) Authors: Grezio, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Sandri, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Argnani, A.; CNR-Bologna; Gasparini, P.; Università di Napoli- Federico II; Selva, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: The general modular Bayesian procedure is applied to provide a probabilistic tsunami hazard assessment (PTHA) for the Messina Strait Area (MSA), Italy. This is the first study in an Italian area where the potential tsunamigenic events caused by both submarine seismic sources (SSSs) and submarine mass failures (SMFs) are examined in a probabilistic assessment. The SSSs are localized on active faults in MSA as indicated by the instrumental data of the catalogue of the Italian seismicity; the SMFs are spatially identified using their propensity to failure in the Ionian and Tyrrhenian Seas on the basis of mean slope and mean depth, and using marine geology background knowledge. In both cases the associated probability of occurrence is provided. The run-ups were calculated at key sites that are main cities and/or important sites along the Eastern Sicily and the Southern Calabria coasts where tsunami events were recorded in the past. The posterior probability distribution combines the prior probability and the likelihood calculated in the MSA. The prior probability is based on the physical model of the tsunami process, and the likelihood is based on the historical data collected by the historical catalogues, background knowledge, and marine geological information. The posterior SSSs and SMFs tsunami probabilities are comparable and are combined to produce a final probability for a full PTHA in MSA. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8225 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8222 Title: A Brownian Model for Recurrent Volcanic Eruptions: an Application to Miyakejima Volcano (Japan) Authors: Garcia-Aristizabal, A.; Center for the Analysis and Monitoring of Environmental Risk (AMRA); Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Fujita, E.; National Research Institute for Earth Science and Disaster Prevention (NIED) Abstract: The definition of probabilistic models as mathematical structures to describe the response of a volcanic system is a plausible approach to characterize the temporal behavior of volcanic eruptions, and constitutes a tool for long-term eruption forecasting. This kind of approach is motivated by the fact that volcanoes are complex systems in which a com- pletely deterministic description of the processes preceding eruptions is practically impos- sible. To describe recurrent eruptive activity we apply a physically-motivated probabilistic model based on the characteristics of the Brownian passage-time (BPT) distribution; the physical process defining this model can be described by the steady rise of a state variable from a ground state to a failure threshold; adding Brownian perturbations to the steady load- ing produces a stochastic load-state process (a Brownian relaxation oscillator) in which an eruption relaxes the load state to begin a new eruptive cycle. The Brownian relaxation os- cillator and Brownian passage-time distribution connect together physical notions of unob- servable loading and failure processes of a point process with observable response statistics. The Brownian passage-time model is parameterized by the mean rate of event occurrence, μ , and the aperiodicity about the mean, α . We apply this model to analyze the eruptive his- tory of Miyakejima volcano, Japan, finding a value of 44.2(±6.5 years) for the μ parameter and 0.51(±0.01) for the (dimensionless) α parameter. The comparison with other models often used in volcanological literature shows that this pysically-motivated model may be a good descriptor of volcanic systems that produce eruptions with a characteristic size. BPT is clearly superior to the exponential distribution and the fit to the data is comparable to other two-parameters models. Nonetheless, being a physically-motivated model, it provides an insight into the macro-mechanical processes driving the system. Wed, 29 Feb 2012 23:00:00 GMT http://hdl.handle.net/2122/8222 2012-02-29T23:00:00Z http://hdl.handle.net/2122/8221 Title: Basic principles of multi-risk assessment: a case study in Italy Authors: Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Garcia-Aristizabal, A.; Center for the Analysis and Monitoring of Environmental Risk (AMRA); Gasparini, P.; Center for the Analysis and Monitoring of Environmental Risk (AMRA); Mastellone, M. L.; Dipartimento di Scienze Ambientali, Seconda Universita' di Napoli; Di Ruocco, A.; Center for the Analysis and Monitoring of Environmental Risk (AMRA) Abstract: The assessment of the impact of different catastrophic events in a given area requires innovative approaches that allow risks comparison and that account for all the possible risk interactions. In the common practice, the risk evaluation related to different sources is generally done through independent analyses, adopting disparate procedures and time–space resolutions. Such a strategy of risks evaluation has some evident major drawbacks as, for example, it is difficult (if not impossible) to compare the risk of different origins, and the implicit assumption of independence of the risk sources leads to neglect possible interactions among threats and/or cascade effects. The latter may amplify the overall risk, and potentially the multi-risk index could be higher than the simple aggre- gation of single-risk indexes calculated considering each source as independent from the others. In this paper, we put forward some basic principles for multi-risk assessment, and we consider a real application to Casalnuovo municipality (Southern Italy), in which we face the problem to make different hazards comparable, and we highlight when and how possible interactions among different threats may become important. Thu, 31 May 2012 22:00:00 GMT http://hdl.handle.net/2122/8221 2012-05-31T22:00:00Z http://hdl.handle.net/2122/7950 Title: Fluorine adsorption by volcanic soils at Mt. Etna, Italy Authors: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Parello, F.; Università di Palermo, Dipartimento DiSTeM Abstract: Fluorine adsorption experiments were performed on 28 samples of the first 5 cm of topsoil collected on the flanks of Mt. Etna. The soil samples were equilibrated with F-rich rainwater (3.25 mg/L) at a soil/water weight ratio of 1/25. Aliquots of the supernatant were collected after 1, 7, 72, 720 and 5640 h and analysed for F content. The soil samples could be subdivided into three groups based on their F-adsorption behaviours after 1 h and at the end of the experiment: (1) negative adsorption (F released from the soil to the solution) after 1 h and negative or moderately positive adsorption at the end, (2) from negative after 1 h to strongly positive adsorption at the end, and (3) always strong positive adsorption. The adsorption capacity of the soils was positively correlated with the soil pH, the contents of finer granulometric fractions (clay and silt) and the weathering stage (as quantified by the chemical alteration index). The most F adsorbing soils are found at the periphery of the volcano where aquifers are more vulnerable to contamination due to the shallower depth of the water table. This study further evidences the importance of the Etnean soils in protecting groundwater from an excessive magmatic F input. Thu, 31 May 2012 22:00:00 GMT http://hdl.handle.net/2122/7950 2012-05-31T22:00:00Z http://hdl.handle.net/2122/7538 Title: Il paesaggio geologico di San Vito Romano Authors: Peppoloni, Silvia; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia Abstract: Quando si parla di paesaggio, specialmente se lo si correla ai centri storici e alle aree urbanizzate, non si può non fare riferimento al paesaggio geologico, inteso come insieme di tutte le caratteristiche geologiche e morfologiche che un territorio possiede, che ne hanno condizionato e ne condizioneranno le trasformazioni. Il paesaggio geologico influenza anche l'evoluzione antropica dei luoghi: il tessuto urbano dei borghi, lo sviluppo delle attività produttive e degli insediamenti umani, il carattere stesso e le abitudini di vita della popolazione, il linguaggio e la cultura, con effetti visibili a breve termine, ma riscontrabili anche a distanza di secoli. Fri, 31 Dec 2010 23:00:00 GMT http://hdl.handle.net/2122/7538 2010-12-31T23:00:00Z http://hdl.handle.net/2122/7393 Title: Investigation of low latitude scintillations in Brazil within the cigala project Authors: Romano, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Bougard, B.; Septentrio N. V., Leuven, Belgium; Aquino, M.; University of Nottingham, Nottingham, United Kingdom; Galera Monico, J. F.; Univ Estadual Paulista, Faculdade de Ciências e Tecnologia, Pres. Prudente, Brazil; Willems, T.; Septentrio N. V., Leuven, Belgium; Solé, M.; Pildo Consulting S.L., Barcelona, Spain Abstract: Ionospheric scintillations are fluctuations in the phase and amplitude of the signals from GNSS satellites occurring when they cross regions of electron density irregularities in the ionosphere. Such disturbances can cause serious degradation on GNSS system performance, including integrity, accuracy and availability. The two indices internationally adopted to characterize ionospheric scintillations are: the amplitude scintillation index, S4, which is the standard deviation of the received power normalized by its mean value, and the phase scintillation index, σΦ, which is the standard deviation of the de-trended carrier phase. At low latitudes scintillations occur very frequently and can be intense. This is because the low latitudes show a characteristic feature of the plasma density, known as the equatorial anomaly, EA, for which a plasma density enhancement is produced and seen as crests on either side of the magnetic equator. It is a region in which the electron density is considerably high and inhomogeneous, producing ionospheric irregularities causing scintillations. The upcoming solar maximum, which is expected to reach its peak around May 2013, occurs at a time when our reliance on high-precision GNSS (such as GPS, GLONASS and the forthcoming GALILEO) has reached unprecedented proportions. Understanding and monitoring of scintillations are essential, so that warnings and forecast information can be made available to GNSS end users, either for global system or local augmentation network administrators in order to guarantee the necessary levels of accuracy, integrity and availability of high precision and/or safety-of-life applications. Especially when facing severe geospatial perturbations, receiver-level mitigations are also needed to minimize adverse effects on satellite signals tracking availability and accuracy. In this context, the challenge of the CIGALA (Concept for Ionospheric scintillation mitiGAtion for professional GNSS in Latin America) project, co-funded by the European GNSS Agency (GSA) through the European 7th Framework Program, is to understand the causes of ionospheric disturbances and model their effects in order to develop novel counter-measure techniques to be implemented in professional multi-frequency GNSS receivers. This paper describes the scientific advancements made within the project to understand and characterize ionospheric scintillation in Brazil by means of historical and new datasets. Wed, 31 Aug 2011 22:00:00 GMT http://hdl.handle.net/2122/7393 2011-08-31T22:00:00Z http://hdl.handle.net/2122/7372 Title: A critical evaluation of tsunami records reported for the Levant Coast from the second millennium BCE to the present Authors: Salamon, A.; Geological Survey, Jerusalem, Israel; Rockwell, T.; Department of Geological Sciences, San Diego State University, CA, USA; Guidoboni, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Comastri, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: We present here a compilation of known, reliable, historically documented tsunamis that have affected the Levant coast between about the 14th century B.C. in Syria, up through the 1956 Jaffa tsunami. The list is based on a careful review of published studies and catalogs that have previously reappraised the original contemporaneous sources. In total, 23 events are included within our compilation, whereas 40 other events were found questionable and excluded. We first describe the dependable tsunamis in detail, including their probable source, whether they were generated from a close or distant earthquake source, or whether they were likely the consequence of an earthquake-triggered submarine slump. This is followed by a critical evaluation of the dubious (uncertain) tsunami reports, as an aid to future investigations that may include a search for new data, fieldwork, modeling and hazard assessments. Next, the list is parameterized in accordance with the format used by the tsunami catalog of the European community. Finally, the historical descriptions are used to assess the impact and effects caused by the tsunamis. The most regularly mentioned (about 90%) is a significant change in sea level. Damage and loss of life in coastal cities and harbors are reported for only one third of the events, leading to the conclusion that the majority of tsunamis on the Levant coast may have resulted in only moderate to no damage. Yet, this is not to mean that the Levantine coast is not at risk. The modern coastline is now far more populated and developed than before, and a similar tsunami that resulted in only moderate damage in the past might be more disastrous in the same location at present. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/7372 2011-12-31T23:00:00Z