http://hdl.handle.net/2122/243 2013-05-20T03:37:01Z http://hdl.handle.net/2122/8677 Title: Damage Distribution in L’Aquila City (Central Italy) during the 6 April 2009 Earthquake Authors: Tertulliani, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Leschiutta, I.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Bordoni, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Milana, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Abstract: The 6 April 2009 Mw 6.3 earthquake (Imax 9–10, Mercalli–Cancani– Sieberg [MCS]) struck the Abruzzi region of central Italy, producing severe damage in the city of L’Aquila. There was heavy damage in the city, especially in the central city area where unusual features of the damage pattern were immediately evident. The aim of this study is to correlate the distribution and the severity of the damage with the geological setting of the area, taking into account the characteristics of the building stock through time. Strong-motion recordings and ambient noise measurements taken soon after the mainshock and during the entire aftershock sequence showed variability in groundmotion amplification throughout the city. Factor of amplification (Fa) results are very high in the southern sector of the city, where the Limi Rossi del Colle dell’Aquila (LRCA) red silts outcrop, and quickly decrease northward, where LRCA is absent. This result correlates with the damage distribution to reinforced concrete (RC) buildings. In the southern sector the rate of collapse of RC buildings was 10%, versus 2% in the rest of the city. General conclusions highlight that the building stock of the city suffered different levels of damage that can be partially explained by the combination of building vulnerability and surface geology. 2012-07-31T22:00:00Z http://hdl.handle.net/2122/8630 Title: Microzonation of Potenza (Southern Italy) in terms of spectral intensity ratio using joint analysis of earthquakes and ambient noise. Authors: Strollo, A.; Helmholtz Centre Potsdam, GFZ; Parolai, S.; Helmholtz Centre Potsdam, GFZ; Bindi, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Chiauzzi, L.; DiSGG University of Basilicata; Pagliuca, R.; DiSGG University of Basilicata; Mucciarelli, M.; DiSGG University of Basilicata; Zschau, J.; Helmholtz Centre Potsdam, GFZ Abstract: A temporary seismic network composed of 11 stations was installed in the city of Potenza (Southern Italy) to record local and regional seismicity within the context of a national project funded by the Italian Department of Civil Protection (DPC). Some stations were moved after a certain time in order to increase the number of measurement points, leading to a total of 14 sites within the city by the end of the experiment. Recordings from 26 local earthquakes (Ml 2.2−3.8 ) were analyzed to compute the site responses at the 14 sites by applying both reference and non-reference site techniques. Furthermore, the Spectral Intensity (SI) for each local earthquake, as well as their ratios with respect to the values obtained at a reference site, were also calculated. In addition, a field survey of 233 single station noise measurements within the city was carried out to increase the information available at localities different from the 14 monitoring sites. By using the results of the correlation analysis between the horizontal-to-vertical spectral ratios computed from noise recordings (NHV) at the 14 selected sites and those derived by the single station noise measurements within the town as a proxy, the spectral intensity correction factors for site amplification obtained from earthquake analysis were extended to the entire city area. This procedure allowed us to provide a microzonation map of the urban area that can be directly used when calculating risk scenarios for civil defence purposes. The amplification factors estimated following this approach show values increasing along the main valley toward east where the detrital and alluvial complexes reach their maximum thickness. 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8590 Title: Overview on the strong motion data recorded during the May-June 2012 Emilia seismic sequence Authors: Luzi, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Pacor, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Ameri, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Puglia, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Burrato, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Massa, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Augliera, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Franceschina, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Lovati, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Castro, R.; Departamento de Sismología, División Ciencias de la Tierra, centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Baja California, 22860, México. Abstract: On 20 May 2012, at 02:03:52 GMT, an earthquake with Mw 6.1 (RCMT, http://www.bo.ingv.it/RCMT) occurred in northern Italy striking a densely populated area. The mainshock was followed a few hours later by two severe aftershocks having the same local magnitude (Ml 5.1, 1 and 2 in Figure 1a), and by hundreds of smaller aftershocks. Nine days later, on 29 May, at 07:00:03 GMT, a second event with moment magnitude Mw 6.0 (RCMT, http://www.bo.ingv.it/RCMT) occurred to the west, on an adjacent fault segment. This event was also followed by hundreds of aftershocks, three of them having local magnitude 5.3, 5.2 and 5.1 (3, 4 and 5, respectively, in Figure 1a) (locations from Istituto Nazionale di Geofisica e Vulcanologia, hereinafter INGV, http://iside.rm.ingv.it/; Malagnini et al., 2012; Scognamiglio et al., 2012). Despite the moderate number of casualties if compared to other major events in the Italian history, the economic loss was extremely high, resulting in about EUR 5 billion (AON Benfield, 2012, http://www.aon.com/), as the majority of Italian industrial activities and infrastructures concentrate in this area, the eastern Po plain, which is the largest sedimentary basin in Italy. The mainshocks are associated to two thrust faults with an approximate E-W trend dipping to the South (Figure 1b). The majority of the faults in this region are located in the upper crust, at depths lower than 10 km. The two main shocks are among the strongest earthquakes generated by thrust faults ever recorded in Italy in the instrumental era. The Emilia sequence has been extensively recorded by several strong-motion networks, operating in the Italian territory and neighbouring countries. Some of the networks acquire continuous data streams at their national data centres, which are nodes of EIDA (European Integrated Data Archive, hhtp://eida.rm.ingv.it), a federation of several archives, so that the waveforms can be obtained immediately after the occurrence of an event. Other networks, such as the Italian accelerometric network (RAN), managed by the Italian Department of the Civil Protection (hereinafter DPC), distribute the acceleration waveforms through their web site (http://protezionecivile.gov.it). The data set explored in this study is relative to the six events of the sequence having Ml > 5 (Table 1) and consists in 365 accelerograms recorded within a distance of 200 km from the epicentres, that were provided by the permanent and temporary seismic networks of INGV, the Swiss Seismological Service (SED, http://www.seismo.ethz.ch/index) and the DPC. 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8582 Title: Topographic amplification from recorded earthquake data and numerical simulations Authors: Cauzzi, Carlo; Swiss Seismological Service (SED-ETHZ), Zürich, Switzerland; Fäh, Donat; Swiss Seismological Service (SED-ETHZ), Zürich, Switzerland; Pessina, Vera; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Faccioli, Ezio; Department of Structural Engineering, Politecnico di Milano, Italy; Smerzini, Chiara; Department of Structural Engineering, Politecnico di Milano, Italy Abstract: With the aim of contributing to the refinement of the next generation of tools for seismic hazard analyses, we present here an attempt at including topographic amplification factors in GMPEs, thus broadening the traditional options for site effects. With a view to critically discuss and complement with new data the approach of Cauzzi et al. (2010) and Paolucci (2002), information from additional numerical models including crustal layering are taken into account. The indications obtained from the numerical simulations are cross-checked against and consolidated by analyses of the residuals of a selection of strong- and weak-motion observations on topographic reliefs in Italy and Switzerland (carefully selected via GIS) with respect to a set of largely used GMPEs. 2012-09-23T22:00:00Z http://hdl.handle.net/2122/8562 Title: CRISIS2008: A Flexible Tool to Perform Probabilistic Seismic Hazard Assessment Authors: Ordaz, M.; Martinelli, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; D'Amico, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Meletti, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia Abstract: In the frame of the Italian research project INGV-DPC S2 (http://nuovoprogettoesse2.stru.polimi.it/), funded by the Dipartimento della Protezione Civile (DPC; National Civil Protection Department) within the agreement 2007-2009, a tool for probabilistic seismic hazard assessment (PSHA) was developed. The main goal of the project was to provide a flexible computational tool for PSHA; the requirements considered essential for the success of the project included: • ability to handle both stationary and non-stationary earthquake time-occurrence models; • ability to use ground-motion prediction models that are not parametric equations but probabilistic "footprints" of the intensities generated by earthquakes of known magnitude and focal characteristics. Usually, these footprints are results of ground motion simulations. Some commonly used programs (e.g., FRISK, by McGuire, 1978; SEISRISK III, by Bender and Perkins, 1987) and more recent and state-of-the-art tools (e.g. OpenSHA, by Field et al., 2003, http://www.opensha.org; OpenQuake, http://openquake.org) for PSHA were analyzed. It was decided to focus on CRISIS2007, which was already a mature and well known application (e.g., Kalyan Kumar and Dodagoudar, 2011; Teraphan et al., 2011; D’Amico et al., 2012; see also http://ecapra.org/CRISIS-2007), but also suitable for additional development and evolution since its source code is freely available on request. The computational tool resulted in an extensive redesign and renovation of the previous CRISIS2007 version. CRISIS is a computer program for PSHA, originally developed in the late 1980's using Fortran as programming language (Ordaz, 1991). In this format, still without a graphical user interface (GUI), it was distributed as part of SEISAN tools (Ottemöller et al., 2011). Ten years later, a GUI was constructed, generating what was called CRISIS99 (Ordaz, 1999). In this version, all the graphic features were written in Visual Basic, but the computation engine remained a Fortran dynamic link library. The reason for the use of mixed-language programming was that computations in Visual Basic were extremely slow. Around 2007 the program was upgraded, in view of the advantages offered by the object-oriented technologies. An object-oriented programming language was required and the natural choice was Visual Basic.Net. In the new version (called CRISIS2007), both the GUI and the computation engine were written in the same language. Finally, in the frame of the mentioned S2 project, starting from 2008, the program was split into two logical layers: core (CRISIS Core Library) and presentation (CRISIS2008). In addition, a new presentation layer was developed for accessing the same functionalities via Web (CRISISWeb). It is worth noting that CRISIS has been mainly written by people that are, at the same time, PSHA practitioners. Therefore, the development loop has been relatively short, and most of the modifications and improvements have been made to satisfy the needs of the developers themselves. 2013-04-30T22:00:00Z http://hdl.handle.net/2122/8559 Title: A reappraisal of seismic Q evaluated in Campi Flegrei caldera. Receipt for the application to risk analysis Authors: Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Bianco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia Abstract: The civil defense of Italy and the European community have planned to reformulate the volcanic risk in several volcanic areas of Italy, among which Mt. Vesuvius and Campi Flegrei, by taking into account the possible occurrence of damaging pre- or syn-eruptive seismic events. Necessary to achieve this goal is the detailed knowledge of the local attenuation–distance relations. In the present note, we make a survey of the estimates of seismic quality factor (the inverse is proportional to the attenuation coefficient with distance) reported in literature for the area of Campi Flegrei where many, but sometimes contradictory results have been published on this topic. We try to review these results in order to give indications for their correct use when calculating the attenuation laws for this area. 2013-03-31T22:00:00Z http://hdl.handle.net/2122/8544 Title: ShakeMaps during the Emilia sequence Authors: Lauciani, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Faenza, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Michelini, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia Abstract: There is no abstract 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8524 Title: Use of combined scaling of real seismic records to obtain code-compliant sets of accelerograms: application for the city of Bucharest Authors: Craifaleanu, I.-G.; Technical University of Civil Engineering Bucharest; Borcia, I. S.; National R&D Institute "URBAN-INCERC" Abstract: A recently proposed method for scaling real accelerograms to obtain sets of code-compliant records is assessed. The method, which uses combined time and amplitude scaling, corroborated with an imposed value of an instrumental, Arias-type intensity, allows the generation of sets of accelerograms for which the values of the mean response spectrum for a given period range are not less than 90% of the elastic response spectrum specified by the code. The method, which is compliant with both for the Romanian seismic code, P100-1/2006, and Eurocode 8, was described in previous papers. Based on dynamic analyses of single-degree-of freedom (SDOF) and of multi-degree-of-freedom (MDOF) systems, a detailed application and assessment of the method is performed, for the case of the long corner period design spectrum in Bucharest. Conclusions are drawn on the advantages of the method, as well as on its potential improvement in the future. 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8501 Title: Mazara del Vallo tide gauge observations (1906-1916): land subsidence or sea level rise? Authors: Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Spada, G.; Dipartimento di Scienze di Base e Fondamenti, Urbino University “Carlo Bo”; Antonioli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Galassi, G.; Dipartimento di Scienze di Base e Fondamenti, Urbino University “Carlo Bo” Abstract: Tide gauge data constitute an invaluable tool for the interpretation of short and long-term sea level changes occurring in the Mediterranean Sea. The complex geophysical environment and the limited amount of sufficiently long records make the interpretation of local signals problematic, since these are often affected by interlacing processes. Starting from newly disclosed tide gauge records from the site of Mazara del Vallo (SW Sicily), we analyze simultaneously the time series available from other locations in Sicily across the beginning of the 20th century (Messina and Palermo). Despite the limited record length, we show that these observations provide new perspectives on the causes of the observed sea level variations in the central Mediterranean region, and in particular they challenge previous tenets regarding the extent of land movements caused by the 1908 Messina Straits earthquake. 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8457 Title: FINITE FAULT MODELING OF STRONG GROUND MOTIONS USING AN EMPIRICAL GREEN’S FUNCTION APPROACH Authors: Scognamiglio, Laura; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia Abstract: The purpose of this study is to test the ground motion synthesis methodology outlined by Hutchings and Wu (1990) and further developed by Hutchings et al. (1991, 1994), and verify its capacity of being used as a predicting tool in strong ground motion seismology as developed by Hutchings (1991) and Hutchings et al. (1996). The earthquake chosen for this test is the 26 September 1997, 09:40, Mw=6.0 Colfiorito Earthquake (Italy). 2005-01-09T23:00:00Z