http://hdl.handle.net/2122/280 2013-05-23T13:44:53Z http://hdl.handle.net/2122/8637 Title: Empirical calibration of local magnitude datasets versus moment magnitude in Italy Authors: Gasperini, P.; Università di Bologna; Lolli, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Vannucci, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: Using general orthogonal regressions (GORs), we calibrated local magnitudes, estimated in Italy using various methods in different periods of time from 1981 to 2010, with a set of homogeneous moment magnitudes (Mw). Magnitude uncertainties, necessary for the application of GOR methods, are inferred by a trial-anderror procedure based on a priori information and empirical regression results. We found that local magnitudes determined using real or synthesized Wood–Anderson waveforms (ML) scale 1:1 with Mw in most cases but in general underestimate Mw by about 0.1–0.2 magnitude units. The only significant deviation from the 1:1 scaling concerns the most recent data provided by the online ISIDE bulletin of the Istituto Nazionale di Geofisica e Vulcanologia and is probably due to the use of a distance correction table (−log A0) not fully appropriate for the Italian area. Magnitudes computed from the duration of the seismogram coda (MD) do not generally scale 1:1 with Mw and are also underestimated. The relevant regression coefficients vary significantly from one data set to another depending on the empirical formulas used by different catalogs and bulletins. The derived regression coefficients are used to build a homogenized catalog in terms of Mw that also includes a consistent estimate of uncertainty for all reported magnitudes. The analysis of the frequency–magnitude distribution of the resulting catalog, covering 30 years of data, shows a b-value slightly lower than 1, which is reasonably uniform over the different time intervals and data sets. It also shows a progressive decay of the earthquake rates below the best-fit straight line for Mw >4:5 that might reflect a magnitude distribution truncated or tapered to relatively small maximum magnitudes for some Italian seismic zones with low activity. This behavior also seems to exclude a characteristic earthquake recurrence mechanism for Italy. 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8625 Title: Toward Reliable Characterization of Sites With Pronounced Topography and Related Effects on Ground Motion Authors: Burianek, J; ETH Zurigo; Cauzzi, C; ETH Zurigo; Fah, D; ETH Zurigo; Bard, P.Y.; ISTerre; Cornou, C; ISTerre; Pitilakis, K; University of Thessaloniki; Massa, Marco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Theodulidis, N; Institute of Engineering Seismology and Earthquake Engineering, Thessaloniki; Bertrand, E; CETE Editors: WCEE proceedings Abstract: Here we present first results of a joint effort undertaken in ongoing European project NERA -JRA1, which aims at establishing scientifically solid and practically acceptable propositions to incorporate surface topography effects in seismic hazard estimates. We assembled a dataset of both ambient vibration and earthquake recordings acquired at 40 European sites with pronounced topography. It comprises a wide variety of sites including populated hills and even extreme cases of unstable rock slopes in Alpine regions. Results of the polarisation analysis for the two sites presented here show the peculiarity of the topographic site effects. 2013-09-24T22:00:00Z http://hdl.handle.net/2122/8624 Title: Seismic amplification in presence of topography and their consequences for ground motion predictions and seismic code for building: the case of Italy Authors: Massa, Marco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Lovati, Sara; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Barani, Simone; Università di Genova Editors: WCEE proceedings Abstract: This work talks about the relevance of topographic effects in local site response evaluations. In this way some Italian test sites, characterized by the presence of a seismic station installed at the top of a steep topography, were investigated. The influence of the morphology was evaluated, at first, by performing rotational spectral ratio analyses, both in term of single station measurements (i.e. horizontal to vertical spectral ratio, HVSR) and, if possible, also considering reference sites (i.e.standard spectral ratio, SSR) and, at second, evaluating the residuals (logarithmic difference between observed and predicted data) estimated in term of acceleration response spectra for period up to 2.0 s. In this way, the ground motion prediction equations calibrated for Italy by Bindi et al., 2010 were considered. Finally, in correspondence of two selected topographies with seismic stations installed both at the top and at the base, the design elastic acceleration response spectra as proposed by the Italian seismic regulations (NTC, 2008) were evaluated in terms of shape and amplitude. 2013-09-24T22:00:00Z http://hdl.handle.net/2122/8623 Title: Topographic Effects in Probabilistic Seismic Hazard Analysis: The Case of Narni, Central Italy Authors: Barani, Simone; Università Genova; Massa, Marco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Lovati, Sara; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Ferretti, Gabriele; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia Editors: WCEE proceedings Abstract: This study presents a probabilistic method for estimating the ground motion hazard at sites presenting topographic irregularities. This method is applicable to topographic crests or ridges which may affect site response, producing 2D (or 3D) amplification effects. The method is based on a set of 2D numerical analyses that are carried out using multiple accelerograms from worldwide weak and strong earthquakes recorded on rock. Numerical analyses are performed to compute site-specific frequency-dependent amplification factors to be included into the ground motion prediction equation used in the seismic hazard computation. The hazard at the top of the ridge is then assessed by running a conventional probabilistic seismic hazard analysis (PSHA) with the attenuation relationship modified to include the site response. An application to the case study of Narni (Central Italy) is presented in this work. 2013-09-24T22:00:00Z http://hdl.handle.net/2122/8622 Title: Real Time acquisition and processing of strong motion data in Northern Italy: the RAIS network. Authors: Massa, Marco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Lovati, Sara; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Franceschina, Gian Lorenzo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Augliera, Paolo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia Editors: WCEE proceedings Abstract: This work summarizes the characteristics of a strong motion network (RAIS, in Italian: “Rete Accelerometrica in Italia Settentrionale”, Strong Motion Network in Northern Italy) installed in northern Italy since 2006. The main goal of the RAIS is both to collect data with a wide range of magnitude, allowing us to increase the knowledge of the covered area, and to assure real time high quality data in case of strong events. For each recorded earthquake data are automatically processed in order to fast disseminate the most important ground motion parameters (peak ground acceleration and velocity, 5% damped acceleration, pseudo-velocity and relative response spectra, Arias and Housner intensities). Moreover, for each event, at each recording site, the Horizontal to Vertical Spectral Ratio are calculated. The analysis and metadata related to each event are collected in a web site (http://rais.mi.ingv.it) while the waveforms are distributed at different data center. 2013-09-24T22:00:00Z http://hdl.handle.net/2122/8602 Title: The building up process of a macroseismic intensity database Authors: Mario, Locati; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Daniele, Viganò; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia Abstract: Since the late nineties Italy has a well-established tradition of making available on the Internet a national macroseismic intensity database. The last updated version called DBMI11 was released in December 2011. By using this public database everyone can obtain information about the effects caused in a populated place by an earthquake of the past. A huge quantity of well organised historical information can be effortlessly retrieved and used as the background information of the seismic hazard assessment. Other similar activities are carried out by the same DBMI working group: the creation of a transnational European database called AHEAD (Archive of historical Earthquake Data) and the related effort of supporting the growth of other European intensity databases (Catalonia, Spain, Portugal, Greece and UK) and, at world-wide scale, the support for the "Global Earthquake History", the GEM (Global Earthquake Model) global component. This presentation will describe how these databases are built, how they are structured and which tools are used both for managing data and for the Internet publication. 2012-06-11T22:00:00Z http://hdl.handle.net/2122/8601 Title: The University of Athens Hellenic Macroseismic Database for Historical Earthquakes Authors: Vassiliki, Kouskouna; University of Athens, Department of Geophysics-Geothermics, Greece; Konstantinos, Taxeidis; University of Athens, Department of Geophysics-Geothermics, Greece; Mario, Locati; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Giorgos, Sakkas; University of Athens, Department of Geophysics-Geothermics, Greece; Kostas, Makropoulos; University of Athens, Department of Geophysics-Geothermics, Greece; Massimiliano, Stucchi; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia Abstract: During the last decade, a systematic study of historical earthquakes leading to the quantification of earthquake effects in terms of macroseismic datapoints (MDPs) and, consequently, to earthquake parameters, has been carried out in the Laboratory of Seismology of the University of Athens. For each earthquake, the available background information has been evaluated and the corresponding macroseismic intensities assessed in terms of EMS98. A considerable amount of studied earthquakes contributed to the Archive of Historical EArthquake Data (AHEAD) and MDPs are now part of its European Macroseismic Database, via European initiatives (NERIES, SHARE). Based on standards proposed by AHEAD, a local database was designed, incorporating historical earthquakes of the period 1000-1899, mainly from the eastern Aegean area. The database includes 93 events with Ix≥7 (683 MDPs) and 1053 events with Ix<7 (1205 MDPs). The data is accessible on the Internet at http://macroseismology.geol.uoa.gr/ 2012-08-18T22:00:00Z http://hdl.handle.net/2122/8600 Title: A New Online Intensity Data Point Database for Portugal Authors: Josep, Batlló; University of Lisbon, CGUL, IDL, Lisbon, Portugal; Fernando, Carrilho; Instituto de Meteorología, Lisbon, Portugal; Paulo, Alves; Instituto de Meteorología, Lisbon, Portugal; Jorge, Cruz; Instituto de Meteorología, Lisbon, Portugal; Mario, Locati; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia Abstract: Online macroseismic intensity databases are becoming common tools in the framework activities related to seismic hazard assessment as they can offer a consistent information background. In Europe, institutions such as INGV (IT), ETH (CH) and Sisfrance (FR) have well-established Macroseismic Intensity Databases. In the framework of the EC projects NERIES (2006-2010) and SHARE (2009-2012), the European "Archive of Historical EArthquake Data" AHEAD was established. Other European institutions are now in the process of creating their own intensity databases following such a proposed common standard. Portugal is among those countries working on a macroseismic intensity database, as at present an updated general compilation of the mainland Portugal macroseismicity is still unavailable. The IM, has among its short term objectives to compile a macroseismic database and to give free access to it on the web. To manage it, the MIDOP software, created and developed by the Italian INGV has been selected. It allows easy access to earthquake listing and visualization of geographical distribution of intensity data points through a web page without the need of installing a complex infrastructure. MIDOP underlying structure strictly follows the standard proposed by AHEAD and with its adoption the collected data will be compatible with other national databases. The status of the project is here presented. 2012-09-23T22:00:00Z http://hdl.handle.net/2122/8599 Title: Archivo online de datos macrosísmicos de la península Ibérica Authors: Antoni, Roca; Instititut Geològic de Catalunya, Barcelona, Spain; Mario, Locati; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Teresa, Susagna; Instititut Geològic de Catalunya, Barcelona, Spain; Instititut Geològic de Catalunya, Fleta; Instititut Geològic de Catalunya, Barcelona, Spain; Jordi, Pujol; Instititut Geològic de Catalunya, Barcelona, Spain; Josep, Batlló; University of Lisbon, CGUL, IDL, Lisbon, Portugal; José Francisco, Valero; Instituto Geográfico Nacional, Madrid, Spain; José Manuel, Martínez-Solares; Instituto Geográfico Nacional, Madrid, Spain; Jorge, Cruz; Instituto de Meteorología, Lisbon, Portugal; Paulo, Alves; Instituto de Meteorología, Lisbon, Portugal; Augusto Antonio, Gómez Capera; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Massimiliano, Stucchi; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia Abstract: An application has been adopted to visualize macroseismic data of the Iberian Peninsula. Three institutions, Institut Geològic de Catalunya (IGC), Instituto Geográfico Nacional (IGN), from Spain and Instituto de Meteorologia from Portugal have already implemented in their web sites with information on the most important earthquakes. A computer programe (MIDOP, Macroseismic Intensity Data Online Publisher) was created by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in order to easily allow theobtention of Earthquake listing and geographical distribution of intensity data points through a web page. 2011-05-09T22:00:00Z http://hdl.handle.net/2122/8552 Title: Coseismic deformation and source modeling of the May 2012 Emilia (Northern Italy) earthquakes Authors: Pezzo, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Merryman Boncori, J. P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Tolomei, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Salvi, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Atzori, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Antonioli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Trasatti, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Novali, F.; Tele-Rilevamento Europa - T.R.E. srl; Serpelloni, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Candela, L.; Agenzia Spaziale Italiana, Unità Osservazione della Terra; Giuliani, R.; Dipartimento della Protezione Civile, Ufficio Rischio Sismico Abstract: On May 20th, 2012, an ML 5.9 earthquake (Table 1) occurred near the town of Finale Emilia, in the Central Po Plain, Northern Italy (Figure 1). The mainshock caused 7 casualties and the collapse of several historical buildings and industrial sheds. The earthquake sequence continued with diminishing aftershock magnitudes until May 29th, when an ML 5.8 earthquake occurred near the town of Mirandola, ~12 km WSW of the mainshock (Scognamiglio et al., 2012). This second mainshock started a new aftershock sequence in this area, and increased structural damage and collapses, causing 19 more casualties and increasing to 15.000 the number of evacuees. Shortly after the first mainshock, the Department of Civil Protection (DPC) activated the Italian Space Agency (ASI), which provided post-seismic SAR Interferometry data coverage with all 4 COSMO-SkyMed SAR satellites. Within the next two weeks, several SAR Interferometry (InSAR) image pairs were processed by the INGV-SIGRIS system (Salvi et al., 2012), to generate displacement maps and preliminary source models for the emergency management. These results included continuous GPS site displacement data, from private and public sources, located in and around the epicentral area. In this paper we present the results of the geodetic data modeling, identifying two main fault planes for the Emilia seismic sequence and computing the corresponding slip distributions. We discuss the implication of this seismic sequence on the activity of the frontal part of the Northern Apennine accretionary wedge by comparing the co-seismic data with the long term (geological) and present day (GPS) velocity fields. 2012-12-31T23:00:00Z