78 research outputs found

    Seismic hazard assessment in terms of macroseismic intensity for the Italian area

    Get PDF
    A seismic hazard map, in terms of macro seismic intensity with 10% probability of exceedance in 50 years, is proposed for the Italian territory. The input elements used to evaluate the seismic hazard are: the seismogenic zoning ZS9 (Meletti et al., 2007), the earthquake catalogue CPTI04 (Gruppo di lavoro CPTI04, 2004) and intensity attenuation relationships. The first two elements and the historical and statistical completeness of the catalogue are those used in the national seismic hazard map for Italy MPS04 (Gruppo di Lavoro MPS, 2004). Two intensity attenuation models are used: 1) one national relationship obtained with a new approach by Pasolini et al. (2006) and a relationship for the Etna volcanic zone proposed by Azzaro et al. (2006) 2) a set of regional relationships derived from a previous cubic model (Berardi et al., 1993) which is recalibrated in the present study using the macro seismic intensity database DBMI04 (Stucchi et al., 2007), which was used for compiling CPTI04. The computer code adopted to evaluate the seismic hazard, with the elements cited above, is SeisRisk III (Bender and Perkins, 1987), which has been modified within this study to incorporate the aleatory variability of the ground motion (macroseismic intensity). A logic-tree framework allowed to explore some possible alternatives of epistemic character. The seismic hazard map obtained in terms of intensity was subsequently transformed into PGA by means of a linear relation between intensity and PGA, in order to compare it with the recently national seismic hazard map MPS04

    Rapid estimation of the seismic impact through the active contribution of the civil protection volunteers

    Get PDF
    Immediately after an earthquake, a rapid estimation of the seismic impact is crucial to carrying out a prompt and appropriate Civil Protection response. This is particularly important in districts characterized by frequent and moderate-to-high seismicity, as is the case in the north-eastern part of Italy. In this paper, the authors illustrate an innovative approach developed in the Friuli Venezia Giulia Region (in north-eastern Italy), based on the active contribution of Civil Protection volunteers. The methodology is based on the rapid and pre-codified communication of the earthquake effects, focusing on two main aspects: (i) the observed effects on people and buildings in the urban areas, and (ii) the structural and non-structural damage observed on pre-identified buildings. In particular, this paper illustrates the methodology and its integration into the seismic emergency plans of the municipalities in the Friuli Venezia Giulia Region and discusses the first test, which occurred during a full-scale exercise and on the occasion of recent minor earthquakes affecting the area. \ua9 2016-OGS

    Assessing the completeness of Italian historical earthquake data

    Get PDF
    The assessment of the completeness of historical earthquake data (such as, for instance, parametric earthquake catalogues) has usually been approached in seismology - and mainly in Probabilistic Seismic Hazard Assessment(PSHA) - by means of statistical procedures. Such procedures look «inside» the data set under investigation and compare it to seismicity models, which often require more or less explicitly that seismicity is stationary. They usually end up determining times (Ti), from which on the data set is considered as complete above a given magnitude (Mi); the part of the data set before Ti is considered as incomplete and, for that reason, not suitable for statistical analysis. As a consequence, significant portions of historical data sets are not used for PSHA. Dealing with historical data sets - which are incomplete by nature, although this does not mean that they are of low value - it seems more appropriate to estimate «how much incomplete» the data sets can be and to use them together with such estimates. In other words, it seems more appropriate to assess the completeness looking «outside » the data sets; that is, investigating the way historical records have been produced, preserved and retrieved. This paper presents the results of investigation carried out in Italy, according to historical methods. First, the completeness of eighteen site seismic histories has been investigated; then, from those results, the completeness of areal portions of the catalogue has been assessed and compared with similar results obtained by statistical methods. Finally, the impact of these results on PSHA is described

    Improving pre-operative planning of robot assisted nephron sparing surgery using three-dimensional anatomical model

    Get PDF
    Introduction Despite the introduction of robot-assisted surgery in daily clinical practice, complex renal masses are still challenging even for expert surgeon. In this scenario 3D anatomical models and augmented reality represent valuable tools for the surgeon. Materials and methods We present a challenging case where PN was mandatory to preserve the overall renal function. The patient was 69 years old, with indwelling catheter for BPH and Parkinson disease. After a single episode of hematuria with negative cystoscopy, a cT1N0M0 renal cancer was diagnosed (38 mm maximum diameter). Pre-operative three-dimensional (3D) model was obtained. After multidisciplinary discussion robot-assisted partial nephrectomy was proposed. The surgery was planned according to the anatomical model. Results Before the procedure a 7Ch single loop ureteral stent was placed. The surgery was carried out in 220 minutes. Selective ischaemia was perfomed for 24 minutes. Estimated blood loss was 400cc. No post-operative complications were observed. Ureteral stent was removed 4 days after the surgery. Definitive histological examination described a pG2-3 T1a Nx R0 clear cell renal carcinoma. Conclusion In selected cases 3D model result to be a useful tool for the pre-operative planning of the surgery

    Seismic hazard for the Trans Adriatic Pipeline (TAP). Part 2: broadband scenarios at the Fier Compressor Station (Albania)

    Get PDF
    AbstractTo ensure environmental and public safety, critical facilities require rigorous seismic hazard analysis to define seismic input for their design. We consider the case of the Trans Adriatic Pipeline (TAP), which is a pipeline that transports natural gas from the Caspian Sea to southern Italy, crossing active faults and areas characterized by high seismicity levels. For this pipeline, we develop a Probabilistic Seismic Hazard Assessment (PSHA) for the broader area, and, for the selected critical sites, we perform deterministic seismic hazard assessment (DSHA), by calculating shaking scenarios that account for the physics of the source, propagation, and site effects. This paper presents a DSHA for a compressor station located at Fier, along the Albanian coastal region. Considering the location of the most hazardous faults in the study site, revealed by the PSHA disaggregation, we model the ground motion for two different scenarios to simulate the worst-case scenario for this compressor station. We compute broadband waveforms for receivers on soft soils by applying specific transfer functions estimated from the available geotechnical data for the Fier area. The simulations reproduce the variability observed in the ground motion recorded in the near-earthquake source. The vertical ground motion is strong for receivers placed above the rupture areas and should not be ignored in seismic designs; furthermore, our vertical simulations reproduce the displacement and the static offset of the ground motion highlighted in recent studies. This observation confirms the importance of the DSHA analysis in defining the expected pipeline damage functions and permanent soil deformations

    Earthquake rupture forecasts for the mps19 seismic hazard model of Italy

    Get PDF
    In recent years, new approaches for developing earthquake rupture forecasts (ERFs) have been proposed to be used as an input for probabilistic seismic hazard assessment (PSHA). Zone-based approaches with seismicity rates derived from earthquake catalogs are commonly used in many countries as the standard for national seismic hazard models. In Italy, a single zone-based ERF is currently the basis for the official seismic hazard model. In this contribution, we present eleven new ERFs, including five zone-based, two smoothed seismicity-based, two fault-based, and two geodetic-based, used for a new PSH model in Italy. The ERFs were tested against observed seismicity and were subject to an elicitation procedure by a panel of PSHA experts to verify the scientific robustness and consistency of the forecasts with respect to the observations. Tests and elicitation were finalized to weight the ERFs. The results show a good response to the new inputs to observed seismicity in the last few centuries. The entire approach was a first attempt to build a community-based set of ERFs for an Italian PSHA model. The project involved a large number of seismic hazard practitioners, with their knowledge and experience, and the development of different models to capture and explore a large range of epistemic uncertainties in building ERFs, and represents an important step forward for the new national seismic hazard model

    The 9 October 1963 Vajont Catastrophe from the Point of View of the WWSSN-LP Recordings of the TRI-117 Station, Trieste, Italy

    No full text
    In this study, we analyze the seismic signal generated by the 1963 Vajont catastrophic landslide recorded at the Worldwide Standardized Seismographic Station Network- Long Period station of Trieste (Italy). The landslide (nearly 260–270 million m3) invaded an artificial reservoir designed for electrical production, and generated a 220 m high wave that flowed over the dam and claimed the lives of approximately 2000 people. The original seismograms have been digitized and analyzed using time–frequency tools and numerical simulations. The results indicate that a seismic signal comparable to that generated by an Ms 3.7 earthquake was generated by the landslide. Furthermore, the calculatednearly2×1014 Joffrictionalenergy,consideringtheknownparameterofthe mass movement, is compatible with a friction coefficient of 0.29, in excellent agreement with the values from previous studies. The seismic efficiency that we calculate (1:12 × 10−4 –4:45 × 10−4 ), also taking into account available data on the landslide, is within the range of values previously noted in literature. Finally, via the numerical sim- ulations and adopting an ad hoc crustal model for the area, the origin time of the event is estimated at 21 hr 41 min 42 s UTC. The results confirm the importance of the re-analy- sis of analog seismograms with modern tools within a multihazard context
    • …
    corecore