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A prototype system for earthquake early-warning and alert management in southern Italy 总被引：1，自引：0，他引：1
G. Iannaccone A. Zollo L. Elia V. Convertito C. Satriano C. Martino G. Festa M. Lancieri A. Bobbio T. A. Stabile M. Vassallo A. Emolo 《Bulletin of Earthquake Engineering》2010,8(5):1105-1129
The Irpinia Seismic Network (ISNet) is deployed in Southern Apennines along the active fault system responsible for the 1980, November 23, M s 6.9 Campania–Lucania earthquake. It is set up by 28 stations and covers an area of about 100 × 70 km2. Each site is equipped with a 1-g full-scale accelerometer and a short-period velocimeter. Due to its design characteristics, i.e., the wide dynamic range and the high density of stations, the ISNet network is mainly devoted to estimating in real-time the earthquake location and magnitude from low- to high- magnitude events, and to providing ground-motion parameters values so to get some insights about the ground shaking expected. Moreover, the availability of high-quality of data allows studying the source processes related to the seismogenetic structures in the area. The network layout, the data communication system and protocols and the main instrumental features are described in the paper. The data analysis is managed by Earthworm software package that also provides the earthquake location while custom software has been developed for real-time computation of the source parameters and shaking maps. Technical details about these procedures are given in the article. The data collected at the ISNet stations are available upon request. 相似文献
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In this study, we address the issue of short-term to medium-term probabilistic seismic hazard analysis for two volcanic areas,
Campi Flegrei caldera and Mt. Vesuvius in the Campania region of southern Italy. Two different phases of the volcanic activity
are considered. The first, which we term the pre-crisis phase, concerns the present quiescent state of the volcanoes that is characterized by low-to-moderate seismicity. The second
phase, syn-crisis, concerns the unrest phase that can potentially lead to eruption. For the Campi Flegrei case study, we analyzed the pattern
of seismicity during the 1982–1984 ground uplift episode (bradyseism). For Mt. Vesuvius, two different time-evolutionary models
for seismicity were adopted, corresponding to different ways in which the volcano might erupt. We performed a site-specific
analysis, linked with the hazard map, to investigate the effects of input parameters, in terms of source geometry, mean activity
rate, periods of data collection, and return periods, for the syn-crisis phase. The analysis in the present study of the pre-crisis phase allowed a comparison of the results of probabilistic seismic hazard analysis for the two study areas with those provided
in the Italian national hazard map. For the Mt. Vesuvius area in particular, the results show that the hazard can be greater
than that reported in the national hazard map when information at a local scale is used. For the syn-crisis phase, the main result is that the data recorded during the early months of the unrest phase are substantially representative
of the seismic hazard during the whole duration of the crisis. 相似文献
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Iunio Iervolino Eugenio Chioccarelli Vincenzo Convertito 《Soil Dynamics and Earthquake Engineering》2011
To define reference structural actions, engineers practicing earthquake resistant design are required by codes to account for ground motion likely to threaten the site of interest and also for pertinent seismic source features. In most of the cases, while the former issue is addressed assigning a mandatory design response spectrum, the latter is left unsolved. However, in the case that the design spectrum is derived from probabilistic seismic hazard analysis, disaggregation may be helpful, allowing to identify the earthquakes having the largest contribution to the hazard for the spectral ordinates of interest. Such information may also be useful to engineers in better defining the design scenario for the structure, e.g., in record selection for nonlinear seismic structural analysis. On the other hand, disaggregation results change with the spectral ordinate and return period, and more than a single event may dominate the hazard, especially if multiple sources affect the hazard at the site. This work discusses identification of engineering design earthquakes referring, as an example, to the Italian case. The considered hazard refers to the exceedance of peak ground acceleration and 1s spectral acceleration with four return periods between 50 and 2475 year. It is discussed how, for most of the Italian sites, more than a design earthquake exists, because of the modeling of seismic sources. Furthermore, it is explained how and why these change with the limit state and the dynamic properties of the structure. Finally, it is illustrated how these concepts may be easily included in engineering practice complementing design hazard maps and effectively enhancing definition of design seismic actions with relatively small effort. 相似文献
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Vincenzo Convertito Iunio Iervolino Aldo Zollo Gaetano Manfredi 《Soil Dynamics and Earthquake Engineering》2008,28(6):492-505
The development and implementation of an earthquake early warning system (EEWS), both in regional or on-site configurations can help to mitigate the losses due to the occurrence of moderate-to-large earthquakes in densely populated and/or industrialized areas. The capability of an EEWS to provide real-time estimates of source parameters (location and magnitude) can be used to take some countermeasures during the earthquake occurrence and before the arriving of the most destructive waves at the site of interest. However, some critical issues are peculiar of EEWS and need further investigation: (1) the uncertainties on earthquake magnitude and location estimates based on the measurements of some observed quantities in the very early portion of the recorded signals; (2) the selection of the most appropriate parameter to be used to predict the ground motion amplitude both in near- and far-source ranges; (3) the use of the estimates provided by the EEWS for structural engineering and risk mitigation applications.In the present study, the issues above are discussed using the Campania–Lucania region (Southern Apennines) in Italy, as test-site area. In this region a prototype system for earthquake early warning, and more generally for seismic alert management, is under development. The system is based on a dense, wide dynamic accelerometric network deployed in the area where the moderate-to-large earthquake causative fault systems are located.The uncertainty analysis is performed through a real-time probabilistic seismic hazard analysis by using two different approaches. The first is the Bayesian approach that implicitly integrate both the time evolving estimate of earthquake parameters, the probability density functions and the variability of ground motion propagation providing the most complete information. The second is a classical point estimate approach which does not account for the probability density function of the magnitude and only uses the average of the estimates performed at each seismic station.Both the approaches are applied to two main towns located in the area of interest, Napoli and Avellino, for which a missed and false alarm analysis is presented by means of a scenario earthquake: an M 7.0 seismic event located at the centre of the seismic network.Concerning the ground motion prediction, attention is focused on the response spectra as the most appropriate function to characterize the ground motion for earthquake engineering applications of EEWS. 相似文献
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Rapid estimation of ground-shaking maps for seismic emergency management in the Campania Region of southern Italy 总被引：1，自引：1，他引：0
Vincenzo Convertito Raffaella De Matteis Luciana Cantore Aldo Zollo Giovanni Iannaccone Mauro Caccavale 《Natural Hazards》2010,52(1):97-115
Strong ground-shaking mapping soon after a moderate-to-large earthquake is crucial to recognize the areas that have suffered
the largest damage and losses. These maps have a fundamental role for emergency services, loss estimation and planning of
emergency actions by the Civil Protection Authorities. This is particularly important for areas with high seismic risk levels,
such as the Campania-Lucania Region in southern Italy. Taking advantage of the Irpinia Seismic Network (ISNet), a recently
installed dense and wide dynamic seismic network, we have developed a procedure for rapid estimation of ground-shaking maps
after moderate-to-large earthquakes (GRSmap). This uses an optimal data gridding scheme designed to account for bi-dimensional
features of strong ground-motion fields, such as directivity, radiation patterns and focal mechanisms, to which most damage
can be correlated. The basis of the mapping technique is a triangulation procedure to locally correct predicted data at the
triangle barycentres where their vertices correspond to seismic stations. The method has been tested off-line using a simulated
M 6.6 earthquake located at the centre of ISNet and applied to data of the 23 November 1980 Irpina M 6.9 earthquake recorded by a sparse network. This has highlighted its ability to predict peak ground-motion parameters of
large magnitude earthquakes with respect to the attenuation relationships. 相似文献
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