Estimating the expected seismicity rates of volcano-tectonic earthquakes at Mt. Etna (italy) by a geometric kinematic approach

Seismic hazard studies have been undertaken at Etna volcano in the last years with the aim of estimating the potential of local fault’s activity in generating destructive earthquakes. The target is the mid-term assessment (30, 20, 10 and 5 yrs), as the identification of zones that are exposed to the recurrent seismic shaking may be important for land planning at a local scale, and it represents a valuable complement to establish priority criteria for seismic risk reduction action. The methodologies applied at Mt. Etna area include probabilistic approaches based on the use of historical macroseismic data (the “site approach” by the software code SASHA, see Azzaro et al., 2008) and fault-based time-dependent models in which occurrence probabilities of major earthquakes are estimated through the Brownian Passage Time (BPT) function and the time lapsed since the last event (Azzaro et al., 2012b, 2013b). Mean return period of major earthquakes - strong to destructive events with epicentral intensity I0 ≥ VIII EMS, considered as “proxies” of “characteristic” earthquakes – have been obtained by the fault seismic histories, i.e. the associations “earthquake-seismogenic fault” derived from the historical catalogue of Etnean earthquakes (CMTE Working Group, 2014). Inter-time statistics of major earthquakes have been applied to the Timpe tectonic system, considered as a homogeneous seismotectonic domain (Azzaro et al., 2013b), obtaining a mean recurrence time (Tmean) of 71.3 years, and an aperiodicity factor α (σTmean/Tmean) = 0.42, typical of semi-periodic processes. In the present study we present the preliminary results of an analysis aimed at verifying the variability of the mean occurrence times of major earthquakes generated by the main tectonic systems at Etna (Pernicana and Timpe faults) by using a geological approach based on geometrickinematic parameters (3D dimensions, slip-rates etc) representative of fault activity. Method and input data

Probabilistic seismic hazard assessment in the Mt. Etna region (Italy): application to local volcano-tectonic earthquakes

Earthquakes are, by far, the most relevant source of hazard for the densely urbanised areas of Mt. Etna region. Local communities living in the eastern and southern flanks of the volcano continuously suffer social and economic losses due to the very high occurrence of damaging earthquakes, which produce intensities up to degree X EMS despite of low energy (M < 5.0). Seismic hazard in the Mt. Etna region is controlled by two distinct types of earthquakes, namely regional and local events, which have different magnitudes and frequencies (Azzaro et al., 2008). In particular, hazard deriving from local volcano-tectonic events can be relevant if short exposure times (30 years) are considered, since the reference intensity (Iref) calculated at the exceeding probability of 10% reaches, in some localities, the IX degree (Azzaro et al., 2008; Azzaro et al., 2013). In the framework of the UPStrat-MAFA project, the seismic hazard was performed following the probabilistic approach (PSHA) based on historical macroseismic data, by using the SASHA code (D'Amico and Albarello, 2008; Albarello and D’Amico, 2013) which has been implemented in the project itself. This approach uses intensity site observations to compute the seismic history for each investigated locality; results are obtained in terms of maximum expected intensity with an exceedance probability ≥ 10% for a given exposure time. In this study we produced PSHA maps referred to local volcano-tectonic seismicity

Vulnerability of Building, urban infrastructure and system: The case of Mt. Etna

Natural disasters, such as earthquakes and volcanoes, have strong effects on the socio-economic wellbeing of countries and their people. The consequences of these events can lead to complex cascades of related incidents; when these expand across sectors and borders, and in more serious contexts, they can threaten our basic survivability. These events have clearly demonstrated that preparedness and disaster management is a dynamic process that requires a holistic analysis of critical interdependencies among core infrastructures. In this context of complexity, uncertainty and doubt, the Disruption Index (DI) proposed in the framework of the UPStrat-MAFA project aims to improve our understanding of earthquake and volcano hazards and their impacts. Several guiding principles and methods have been developed to serve as the basis to measure the different earthquake impacts, with analysis and discussion of the data that provide clearer pictures of how the systems and the disruption of their functionality affect an urban area. The main concepts that explain the DI can be found in Ferreira et al. (2014). Constructing the DI requires good quality information about the physical, spatial and vulnerability conditions of the study area; this means the information that reflects the full knowledge of the true situatio

Studio preliminare di due sequenze di microterremoti accadute nel 2011 e nel 2012 nell'area dei Monti Iblei Orientali (Sicilia sudorientale - Italia)

Nell’ottobre 2011 e nel giugno 2012 due sequenze sismiche hanno interessato l’area a sud di Canicattini Bagni, sulle propaggini orientali dei Monti Iblei, in Sicilia sudorientale. Le due sequenze, costituite ognuna da più di un centinaio di scosse, sebbene di modesta energia, sono state avvertite con ansia dalla popolazione provocando anche lievi danni nelle località prossime all’area epicentrale. Al fine di monitorare con maggior dettaglio l’evoluzione della sequenza in corso, la rete sismica permanente gestita dall’Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Etneo - Sezione di Catania (INGV-OE) è stata implementata, subito dopo l’inizio della sequenza di ottobre 2011, da due stazioni mobili digitali in registrazione locale. Successivamente, dopo la ripresa dell’attività sismica nel mese di giugno 2012, le due stazioni mobili digitali sono state reinstallate negli stessi siti utilizzati precedentemente per ulteriori circa quaranta giorni. Le due stazioni mobili, durante il loro periodo di funzionamento, hanno permesso di rilevare un elevato numero di microterremoti. In questo lavoro vengono presentati i risultati preliminari relativi alle due sequenze sismiche allo scopo di definire con estremo dettaglio la struttura sismogenetica attivatasi. È attualmente in corso l’integrazione del dataset acquisito dall’INGV-OE nell’ambito delle attività di monitoraggio, con i dati acquisiti dalle due stazioni mobili installate. La peculiarità delle due sequenze consiste nel fatto che esse: i) rappresentano il maggior rilascio energetico, avvenuto nel corso degli ultimi dieci anni, nell’area iblea; ii) testimoniano la presenza di una sorgente sismogenetica superficiale ben distinta dal pattern sismico tipico dell’Altopiano Ibleo

Occlusal Load Considerations in Implant-Supported Fixed Restorations

The advent of new technologies in the field of medicine and dentistry is creating improvements that lead clinicians to have materials and procedures able to improve patients' quality of life. The aim of this article is to evaluate occlusion load and its consequences on fixed implant-supported prosthesis. New materials have granted clinicians the possibility achieve great aesthetic results in dental prosthesis, and new procedures allow them to standardize and give precise and repeatable results, especially for the functional and long-term stability aspects of products. Some principles should be carefully evaluated and applied to every dental prosthesis; the evaluation of the forces and fitting of meso-structures to dental implants, an aspect that is often not well considered by clinicians, is the main focus of this article

Seismic Hazard Mapping inside the Project SIGMA

The Project SIGMA (Sistema Integrato di sensori in ambiente cloud per la Gestione Multirischio Avanzata) arises from the fields of Information and Communications Technologies (ICT) and advanced applications for the control, monitoring and management of high-risk processes of natural and social origin. SIGMA is a multilevel architecture whose main aim is the acquisition, integration and processing of heterogeneous data from different sources (seismic, volcanic, meteorologic, hydric, pluvial, car traffic, marine traffic, and so on) to manage and elaborate risk mitigation strategies which are important for the emergency management planning. Within the several experimental activities included in the project, there is the designing and realization of a prototype of application platform specialized to provide the operating procedures and software to the public administrations and the industrial companies, for constantly monitoring both the anthropic and natural phenomena in Sicily. In this framework, of course, the seismic risk analysis plays a very important role since Sicily is one of the Italian regions with high seismic risk. Seismic risk assessment may be approached in two different ways: i) as average seismic risk of the buildings and facilities in question during the period considered, combining the vulnerability of different building types and the seismic hazard for the site, which are then expressed in terms of the effects of the events derived from an earthquake catalogue that exceed a specified threshold during a given period; ii) as estimated damage of the buildings and the critical facilities using a scenario input described in terms of the source parameters of the hypocenter as location, magnitude, and so on. Here we deal with the hazard calculation through the code CRISIS (Ordaz, Aguilar and Arboleda) and with the code PROSCEN (PRObabilistic SCENario, [Rotondi and Zonno, 2010]) to obtain earthquake scenario to be used in the latter approach. Indeed, an earthquake scenario is a planning tool that helps decision makers to visualize the specific impact of an earthquake based on the scientific knowledge. An earthquake scenario creates a picture that the members of community can recognize and, at the same time, improves the communication between the scientific, emergency management and policy communities to seismic risk reduction

Does needle calibre affect pain and complication rates in patients undergoing transperineal prostate biopsy? A prospective, randomized trial

Transperineal prostate biopsy is a procedure that can be used to obtain histological samples from the prostate. To improve both the quality of the biopsy core samples and prostate cancer detection, we are currently performing a prospective, randomized trial comparing prostate biopsy samples obtained using an 18 G-needle to those obtained using a 16 G needle. The aim of this preliminary study was to evaluate pain and complication rates in both groups in order to assess whether performing a prostate biopsy with a larger calibre needle is a feasible procedure. One hundred and eighty-seven patients undergoing transperineal prostate biopsy were prospectively evaluated and divided into two groups. The first group (94 patients, Group A) received a transperineal prostate biopsy using a 16 G-needle and the second group (93 patients, Group B) underwent transperineal prostate biopsy with an 18 G-needle. Anaesthesia was obtained with a single perineal injection at the prostatic apex in all subjects. A visual analogue scale (VAS) and facial expression scale (FES) were used to assess pain during multiple steps of the procedure in each group. A detailed questionnaire was used to obtain information about drug use because it could potentially influence the pain and complications that patients experienced. Two weeks after the procedure, early and late complications were evaluated. Statistical analysis was carried out using non-parametric tests. Prostate Specific Antigen (PSA) and drug use were similar at baseline between the two groups. Pain during prostate biopsy, which was measured with both the VAS and FES instruments, did not differ significantly between the 18- and 16 G-needle groups, and no significant differences were found in early or late complication rates between the groups. Transperineal prostate biopsy with a 16 G-needle is a feasible procedure in terms of pain and complication rates. Further studies with larger patient populations are required to assess whether or not this procedure can improve prostate cancer detection rates

Applying the Disruption Index procedure to evaluate the urban seismic risk in the Mt. Etna area (Italy)

The Disruption Index is used here for the assessment of urban disruption in the Mt. Etna area after a natural disaster. The first element of the procedure is the definition of the seismic input, which is based on information about the historical seismicity and seismogenic faults. The second element is the computation of the seismic impact on the building stock and infrastructure in the region considered. Information on urban-scale vulnerability was collected and a geographic information system was used to organize the data relating to buildings and network systems (e. g., typologies, schools, strategic structures, lifelines). The central idea underlying the definition of the Disruption Index is the identification and evaluation of the impacts on a target community, considering the physical elements that contribute most to the severe disruption. The results of this study are therefore very useful for earthquake preparedness planning and for the development of strategies to minimize the risks from earthquakes. This study is a product of the European “Urban Disaster Prevention Strategies using Macroseismic Fields and Fault Sources” project (UPStrat-MAFA European project 2013).PublishedTorino, Italy3T. Pericolosità sismica e contributo alla definizione del rischioope