277 research outputs found
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 textIn 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
Could a Decentralized Onsite Earthquake Early Warning System Help in Mitigating Seismic Risk in Northeastern Italy? The Case of the 1976 Ms 6.5 Friuli Earthquake
No full textIn May 1976, a devastating earthquake of magnitude Ms 6.5 occurred in Friuli, Italy,
resulting in 976 deaths, 2000 injured, and 60,000 homeless. It is notable that, at the time
of the earthquake, only one station was installed in the affected region. The resulting
lack of information, combined with a dearth of mitigation planning for responding to
such events, lead to a clear picture of the impact of the disaster being available only
after a few days.
This region is now covered by nearly 100 seismological and strong-motion stations
operating in real time. Furthermore, 30 average-cost strong-motion stations have been
recently added, with the goals of improving the density of real-time ground-motion
observations and measuring the level of shaking recorded at selected buildings. The
final goal is to allow rapid impact estimations to be made to improve the response
of civil protection authorities. Today, considering the higher density seismological net-
work, new efforts in terms of the implementation and testing of earthquake early
warning systems as a possible tool for mitigating seismic risk are certainly worthwhile.
In this article, we show the results obtained by analyzing in playback and using an
algorithm for decentralized onsite earthquake early warning, broadband synthetic
strong-motion data calculated at 18 of the stations installed in the region, while con-
sidering the magnitude and location of the 1976 Friuli earthquake. The analysis shows
that the anisotropy of the lead times is related not only to the finite nature of the source
but also to the slip distribution. A reduction of 10% of injured persons appears to be
possible if appropriate mitigating actions are employed, such as the development of
efficient automatic procedures that improve the safety of strategic industrial facilities
Available active surveillance follow-up protocols for small renal mass: a systematic review
No full textPurpose: To evaluate follow-up strategies for active surveillance of renal masses and to assess contemporary data. Methods: We performed a comprehensive search of electronic databases (Embase, Medline, and Cochrane). A systematic review of the follow-up protocols was carried out. A total of 20 studies were included. Result: Our analysis highlights that most of the series used different protocols of follow-up without consistent differences in the outcomes. Most common protocol consisted in imaging and clinical evaluation at 3, 6, and 12 months and yearly thereafter. Median length of follow-up was 42 months (range 1–137). Mean age was 74 years (range 67–83). Of 2243 patients 223 (10%) died during the follow-up and 19 patients died of kidney cancer (0.8%). The growth rate was the most used parameter to evaluate disease progression eventually triggering delayed intervention. Maximal axial diameter was the most common method to evaluate growth rate. CT scan is the most used, probably because it is usually more precise than kidney ultrasound and more accessible than MRI. Performing chest X-ray at every check does not seem to alter the clinical outcome during AS. Conclusion: The minimal cancer-specific mortality does not seem to correlate with the follow-up scheme. Outside of growth rate and initial size, imaging features to predict outcome of RCC during AS are limited. Active surveillance of SRM is a well-established treatment option. However, standardized follow-up protocols are lacking. Prospective, randomized, trials to evaluate the best follow-up strategies are pending
Decision-making supports for seismic risk mitigation of schools at a regional scale: the ASSESS project
No full textIn a seismic territory, one of the concerns of the public administrators is to guarantee
people’s safety in case of an earthquake occurrence, mainly in public facilities and in particular
in school buildings. Public administrations are facing a complex problem and they often need
to answer the following questions: what school must be adequate first? Why? What typologies of
intervention are necessary? What level of safety is it possible to reach? How much is the cost of
retrofitting? How many interventions can be managed with the available resources? How to manage/treat
the most critical cases? How to communicate the level of risk to people? These questions
point out that the definition of a rational and effective strategy for the mitigation of seismic risk
implies the necessity to know the level of risk and the criticalities together with the required countermeasures
and their costs. All this knowledge permits to carry out an evaluation of the needed economical
effort in terms of necessary global financial amount and, consequently, the definition of the
practicable strategies for risk mitigation. This problem has been addressed in the ASSESS (Analysis
of the seismic scenarios of the school buildings for a definition of retrofitting priorities for seismic
risk reduction) project, aimed at knowing the seismic risk of the schools of Friuli Venezia Giulia
region for preventive purposes. Specific decision-making supports have been defined in order to
facilitate public administrators in the management of rational seismic risk mitigation strategies
A citizen science approach for supporting rapid earthquake impact assessments (International Journal of Disaster Risk Reduction)
No full textAfter a strong earthquake, the rapid identification of the extent of the affected area is the most crucial task of civil protection authorities. The information provided by those directly affected by an event makes the difference since it offers the opportunity to take advantage of direct observations and, in the case alert systems are available, to verify if they worked properly. Thanks to the fruitful collaboration between the Regional Civil Protection of Friuli Venezia Giulia and the National Institute of Oceanography and Applied Geophysics – OGS in Italy, a procedure for collecting rapid information about the impact of an earthquake using an expert crowdsourcing approach has been in place for some years. The volunteers of the civil protection, appropriately trained, upon receipt of the seismic event notification, are asked to rapidly compile a specific questionnaire, describing the impact of the event. Data are rapidly coded, and the results are summarized in a seismic impact map showing the effect of the earthquake throughout the territory in a simplified way. This map complements the impact estimation provided by the analysis of recorded shaking data. This paper describes the results obtained by analyzing the “Trained Volunteers Seismic Evaluation” questionnaire (TVSE) completed by volunteers for some of the most significant events in recent years
Distribuzione spazio-temporale e caratterizzazione della fagliazione quaternaria in Appennino meridionale.
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