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Napoli, Italy

Gasparini P.,University of Naples Federico II | Manfredi G.,Amra Scarl | Manfredi G.,University of Naples Federico II | Zschau J.,German Research Center for Geosciences
Soil Dynamics and Earthquake Engineering | Year: 2011

Increasing vulnerability of metropolitan areas to earthquake and the very low probability level at which short term earthquake forecasting is possible make earthquake early warning methods (EEW) the main viable alternative for effective risk reduction in cities. Preventive actions, such as retrofitting and building and the diffusion of construction codes, are of course essential. They are not sufficient. A substantial proportion of the population in areas of higher earthquake hazard still reside in buildings that do not meet modern earthquake resistant standards, and cannot currently be strengthened in an economically viable manner. As demonstrated in Japan EEW has the potential of significantly contributing to reduce individual vulnerability of urban population to earthquakes. Future research on EEW should be focused on its implementation to protect lifelines, infrastructures and strategic buildings, and it should include training of administrators and people who can fully exploit the technological advantages offered by EEW systems. In particular it should foresee extensive cost-benefit analysis for each potential application, the identification and solution of legal problems (such as liability in the event of false or missed alarms), education and training, both for mitigation and response, as well as detection and processing within 1 s of the first seismic wave arrivals. Further objectives include the development of people-centred EEW, specialized IT and decision making support systems, integration of sensors, communications and decision making systems, integration into programs of eco-sustainable development, and integration with other EW systems (all hazard systems). © 2010.

Anita G.,Italian National Institute of Geophysics and Volcanology | Sandri L.,Italian National Institute of Geophysics and Volcanology | Marzocchi W.,Italian National Institute of Geophysics and Volcanology | Argnani A.,CNR Marine Science Institute | And 3 more authors.
Natural Hazards | Year: 2012

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. © 2012 Springer Science+Business Media B.V.

Convertito V.,Italian National Institute of Geophysics and Volcanology | Maercklin N.,Amra Scarl | Sharma N.,University of Naples Federico II | Zollo A.,University of Naples Federico II
Bulletin of the Seismological Society of America | Year: 2012

The growing installation of industrial facilities for subsurface exploration worldwide requires continuous refinements in understanding both the mechanisms by which seismicity is induced by field operations and the related seismic hazard. Particularly in proximity of densely populated areas, induced low-to-moderate magnitude seismicity characterized by high-frequency content can be clearly felt by the surrounding inhabitants and, in some cases, may produce damage. In this respect we propose a technique for time-dependent probabilistic seismic-hazard analysis to be used in geothermal fields as a monitoring tool for the effects of on-going field operations. The technique integrates the observed features of the seismicity induced by fluid injection and extraction with a local ground-motion prediction equation. The result of the analysis is the time-evolving probability of exceedance of peak ground acceleration (PGA), which can be compared with selected critical values to manage field operations. To evaluate the reliability of the proposed technique, we applied it to data collected in The Geysers geothermal field in northern California between 1 September 2007 and 15 November 2010 We show that the period considered the seismic hazard at The Geysers was variable in time and space, which is a consequence of the field operations and the variation of both seismicity rate and b-value.We conclude that, for the exposure period taken into account (i.e., two months), as a conservative limit, PGA values corresponding to the lowest probability of exceedance (e.g., 30%) must not be exceeded to ensure safe field operations. We suggest testing the proposed technique at other geothermal areas or in regions where seismicity is induced, for example, by hydrocarbon exploitation or carbon dioxide storage.

Toscano G.,University of Naples Federico II | Colarieti M.L.,Amra Scarl | Greco G.,Amra Scarl
Chemical Engineering Transactions | Year: 2012

Propylene glycol (PG) is a main component in several commercial formulations of aircraft deicing fluids (ADF). Their use is a source of soil pollution along airport runways. Even though PG is biodegradable by soil bacteria, seasonal overloads can give rise to occasional groundwater contamination. A prevention strategy could be the enhancement of biodegradation rate in the unsaturated zone. The effect of addition of nutrients on the kinetics of PG degradation has been studied in soil slurries. In the absence of added nutrients, the aerobic removal kinetics is zero-order in PG concentration over the range 0.05-1 g/L. There is no biomass growth and PG degradation occurs by maintenance metabolism at constant rate depending on the initial concentration of PG-degraders. In the presence of ammonia as a nitrogen source, biomass exponential growth allows a faster aerobic PG degradation. Biomass growth can be detected by the apparent change in PG removal kinetics. Copyright © 2012, AIDIC Servizi S.r.l.

Grezio A.,Italian National Institute of Geophysics and Volcanology | Gasparini P.,Amra Scarl | Gasparini P.,University of Naples Federico II | Marzocchi W.,Italian National Institute of Geophysics and Volcanology | And 2 more authors.
Natural Hazards and Earth System Science | Year: 2012

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 Probability 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 (residential, commercial, industrial) and location (streets); and (iii) the Train and Port Authorities. For human beings, a factor 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. © 2012 Author(s). CC Attribution 3.0 License.

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