Time-dependent neo-deterministic seismic hazard scenarios: Preliminary report on the M6.2 Central Italy earthquake, 24th August 2016
📝 Abstract
A scenario-based Neo-Deterministic approach to Seismic Hazard Assessment (NDSHA) is available nowadays, which permits considering a wide range of possible seismic sources as the starting point for deriving scenarios by means of full waveforms modeling. The method does not make use of attenuation relations and naturally supplies realistic time series of ground shaking, including reliable estimates of ground displacement, readily applicable to complete engineering analysis. Based on the neo-deterministic approach, an operational integrated procedure for seismic hazard assessment has been developed that allows for the definition of time dependent scenarios of ground shaking, through the routine updating of earthquake predictions, performed by means of the algorithms CN and M8S. The integrated NDSHA procedure for seismic input definition, which is currently applied to the Italian territory, combines different pattern recognition techniques, designed for the space-time identification of strong earthquakes, with algorithms for the realistic modeling of ground motion. Accordingly, a set of deterministic scenarios of ground motion at bedrock, which refers to the time interval when a strong event is likely to occur within the alerted area, is defined both at regional and local scale. CN and M8S predictions, as well as the related time-dependent ground motion scenarios associated with the alarmed areas, are routinely updated since 2006. The prospective application of the time-dependent NDSHA approach provides information that can be useful in assigning priorities for timely mitigation actions and, at the same time, allows for a rigorous validation of the proposed methodology. The results from real-time testing of the time-dependent NDSHA scenarios are illustrated with specific reference to the August 24th, 2016 Central Italy earthquake.
💡 Analysis
A scenario-based Neo-Deterministic approach to Seismic Hazard Assessment (NDSHA) is available nowadays, which permits considering a wide range of possible seismic sources as the starting point for deriving scenarios by means of full waveforms modeling. The method does not make use of attenuation relations and naturally supplies realistic time series of ground shaking, including reliable estimates of ground displacement, readily applicable to complete engineering analysis. Based on the neo-deterministic approach, an operational integrated procedure for seismic hazard assessment has been developed that allows for the definition of time dependent scenarios of ground shaking, through the routine updating of earthquake predictions, performed by means of the algorithms CN and M8S. The integrated NDSHA procedure for seismic input definition, which is currently applied to the Italian territory, combines different pattern recognition techniques, designed for the space-time identification of strong earthquakes, with algorithms for the realistic modeling of ground motion. Accordingly, a set of deterministic scenarios of ground motion at bedrock, which refers to the time interval when a strong event is likely to occur within the alerted area, is defined both at regional and local scale. CN and M8S predictions, as well as the related time-dependent ground motion scenarios associated with the alarmed areas, are routinely updated since 2006. The prospective application of the time-dependent NDSHA approach provides information that can be useful in assigning priorities for timely mitigation actions and, at the same time, allows for a rigorous validation of the proposed methodology. The results from real-time testing of the time-dependent NDSHA scenarios are illustrated with specific reference to the August 24th, 2016 Central Italy earthquake.
📄 Content
Time-dependent neo-deterministic seismic hazard scenarios: Preliminary report on the M6.2 Central Italy earthquake, 24th August 2016
Antonella Peresan 1,2,4, Vladimir Kossobokov3,4, Leontina Romashkova3, Andrea Magrin2,
Alexander Soloviev3, Giuliano F Panza4,5
1 - CRS-OGS, National Institute of Oceanography and Experimental Geophysics. Udine. Italy 2 - Department of Mathematics and Geosciences, University of Trieste – Italy 3 - IEPT, Russian Academy of Sciences, Moscow, Russian Federation 4 - International Seismic Safety Organization (ISSO) 5 - Institute of Geophysics, China Earthquake Administration, Beijing
Introduction A reliable and comprehensive characterization of expected seismic ground shaking, eventually including the related time information, is essential in order to develop effective mitigation strategies and increase earthquake preparedness. Forecasting earthquakes and related ground shaking, however is not an easy task and it implies a careful application of statistics to data sets of limited size and different accuracy. Nowadays it is well recognized by the engineering community that standard hazard indicator estimates (e.g. seismic PGA) alone are not sufficient for the adequate design, mainly for special buildings and infrastructures. Moreover, any effective tool for SHA must demonstrate its capability in anticipating the ground shaking related with large earthquake occurrences, a result that can be attained only through rigorous verification and validation process.
A scenario-based Neo-Deterministic approach to Seismic Hazard Assessment (NDSHA) is available nowadays, which considers a wide range of possible seismic sources (including the largest deterministically or historically defined credible earthquake, MCE) as the starting point for deriving scenarios by means of full waveforms modeling, either at national and local scale. The method does not make use of attenuation relations and naturally supplies realistic time series of ground shaking, including reliable estimates of ground displacement readily applicable to seismic isolation techniques. The NDSHA procedure permits to incorporate, as they become available, new geophysical and geological data, leading to the natural definition of a set of scenarios of expected ground shaking at the bedrock. At the local scale, further investigations can be performed taking into account the local soil conditions, in order to compute the seismic input (realistic synthetic seismograms) for engineering analysis of relevant structures, such as historical and strategic buildings. The standard NDSHA has been already applied in several regions worldwide, including a number of local scale studies accounting for two-dimensional and three-dimensional lateral heterogeneities in anelastic media.
Based on the neo-deterministic approach, an operational integrated procedure for seismic hazard assessment has been developed that allows for the definition of time dependent scenarios of ground shaking, through the routine updating of earthquake predictions, performed by means of the algorithms CN and M8S (Peresan et al., 2005). The integrated NDSHA procedure for seismic input definition, which is currently applied to the Italian territory, combines different pattern recognition techniques, designed for the space- time identification of strong earthquakes, with algorithms for the realistic modeling of ground motion. Accordingly, a set of deterministic scenarios of ground motion at bedrock, which refers to the time interval when a strong event is likely to occur within the alerted area, can be defined by means of full waveform modeling, both at regional and local scale. CN and M8S predictions, as well as the related time-dependent ground motion scenarios associated with the alarmed areas, are routinely updated every two months since 2006 (Panza et al., 2012; Peresan et al., 2011).Intermediate-term middle-range earthquake predictions by CN and M8S algorithms CN and M8S predictions, as well as the related time-dependent ground motion scenarios associated with the alarmed areas, are routinely updated every two months since 2006. The rules for the real-time application of CN and M8S algorithms to the Italian territory are described in detail in Peresan et al. (2005), whereas the procedure for the definition of the related ground shaking scenarios is illustrated in Peresan et al. (2011).
The intermediate-term middle-range earthquake prediction experiment, aimed at a real- time testing of M8S and CN predictions for earthquakes with magnitude larger than a given threshold (namely 5.4 and 5.6 for CN algorithm, and 5.5 for M8S algorithm) in the Italian region and its surroundings, is ongoing since 2003. Predictions are regularly updated every two months and a complete archive of predictions is made available on-line (http://www.geoscienze.units.it/esperimento-di-previsione-dei-terremoti-mt.html) , t
This content is AI-processed based on ArXiv data.