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  • 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring  (16)
  • 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology  (13)
  • 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution  (8)
  • Inversion
  • Seismological Society of America  (34)
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  • 1
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    An Almost Fair Comparison Between Earthworm and SeisComp3 (2018)
    Seismological Society of America
    Details
    Publication Date: 2018-03-12
    Description: The paper has not any abstract
    Description: Published
    Description: 720-727
    Description: 2T. Sorgente Sismica
    Description: 1IT. Reti di monitoraggio
    Description: JCR Journal
    Keywords: Earthquake ; Monitoring ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 2
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    The Ongoing Seismic Sequence at the Pollino Mountains, Italy (2015)
    Seismological Society of America
    Details
    Publication Date: 2020-11-26
    Description: A sequence of thousands of small to moderate earthquakes has been occurring since spring 2010 in the Pollino Mountains area, southern Italy, where a seismic gap was previously hypothesized by paleoseismological evidence associated with the lack of major earthquakes in historical catalogs.
    Description: Published
    Description: 955-962
    Description: 2T. Tettonica attiva
    Description: JCR Journal
    Description: restricted
    Keywords: seismic sequence ; earthquake location ; focal mechanism ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 3
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    Macroseismic Intensity Assessment Method for Web Questionnaires (2015)
    Seismological Society of America
    Details
    Publication Date: 2021-03-04
    Description: Macroseismic investigation with data collected through web- based questionnaires is today routinely applied by most impor- tant seismological institutions, such as the U.S. Geological Survey (http://earthquake.usgs.gov/earthquakes/dyfi/; last accessed December 2014), British Geological Survey (http://www. earthquakes.bgs.ac.uk/questionnaire/EqQuestIntro.html; last accessed December 2014), European-Mediterranean Seismological Centre (http://www.emsc-csem.org/Earthquake/Contribute/ choose_earthquake.php?lang=en; last accessed December 2014), Schweizerische Erdbebendienst (http://www.seismo.ethz. ch/eq/detected/eq_form/index_EN; last accessed December 2014), Bureau Central Sismologique Français (http://www .seisme.prd.fr/english.php; last accessed December 2014), and the New Zealand GeoNet project (http://www.geonet.org.nz/ quakes/; last accessed December 2014). The wide diffusion of Internet and the citizen collaboration (crowdsourcing) allow documentation of information on seismic effects and production of a macroseismic field with low costs and almost in real time. Transformation from qualitative information (as given by ques- tionnaires) to numerical quantification is a crucial issue. In the traditional evaluation of intensity, experts used to work through a complex comparison of effects basically driven by personal expe- rience. The major problem with this approach concerns the dif- ficulty in verifing and reproducing the evaluation process due to the lack of a detailed explanation of the employed workflow and to the large variability of possible cases. On the other hand, an automatic method for the estimation of macroseismic intensities needs to be completely well defined and specified in order to be reproducible and verifiable. For these reasons, this paper presents a comprehensive explanation of our intensity assessment method. A useful automatic method for intensity assessment should be computationally fast and strictly follow the macroseismic scales. To meet these requirements in 2010, we proposed a method that firstly quantified the effects using additive scores associated with each answer of the questionnaire item and then determined an intensity estimate for each questionnaire (Sbarra et al., 2010). After a trial period and having collected more than 500,000 questionnaires, we were able to thoroughly test the method. As a result of this testing, we describe here a new improved method that takes into account further factors, such as the situation and the location of the observer (Sbarra et al., 2012, 2014), to obtain a more accurate estimate of the macroseismic intensity degree at the municipality level. In this paper, we show some applications of our method with reference to the Mercalli–Cancani–Sieberg (MCS) scale, because this scale has long been used with Italian earthquakes and allows easy comparison between these intensities and other traditional ones.
    Description: Published
    Description: 985-990
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: 5T. Sorveglianza sismica e operatività post-terremoto
    Description: 4IT. Banche dati
    Description: JCR Journal
    Description: reserved
    Keywords: Macroseismics ; intensity ; questionnaires ; attenuation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 05. General::05.01. Computational geophysics::05.01.05. Algorithms and implementation
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 4
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    Difference in shaking intensity between short and tall buildings: known and new findings (2015)
    Seismological Society of America
    Details
    Publication Date: 2021-03-04
    Description: We investigate the influence of building height on the ability of people to feel earthquakes and observe that, in an urban area, short and tall buildings reach different levels of excitation. We quantify this behavior by analyzing macroseismic reports collected from individuals through the Internet, focusing on transitory effects, therefore in the elastic regime during recent earthquakes in Italy in the local magnitude (ML) range of 3 to 5.9. We find a maximum difference of 0.6 intensity units between the top floors of tall (7–10 stories) and short (1–2 stories) buildings at the highest considered magnitudes. As expected, tall buildings experience greater shaking than short buildings during large earthquakes at large source distances. However, we observe the opposite behavior at close distances when the ML is less than 3.5. These results can be explained by considering the different spectra radiated by small and large earthquakes and the different fundamental mode resonances of buildings (i.e., shorter buildings have higher resonance frequencies and vice versa). Using idealized building models excited by real acceleration time histories, we compute synthetic accelerograms on the top floors of short and tall buildings, and confirm the trend of the observed differences in felt intensities.
    Description: Published
    Description: 1803-1809
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: JCR Journal
    Description: reserved
    Keywords: Macroseismics ; intensity ; building height ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 5
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    Faulting and Ancient Earthquakes at Sybaris Archaeological Site, Ionian Calabria, Southern Italy (2015)
    Seismological Society of America
    Details
    Publication Date: 2020-02-24
    Description: The Sybaris archaeological site, founded by the Greeks in 720 B.C., is located within the Sibari Plain near the Crati River mouth (Ionian northern Calabria, southern Italy), in an almost flat and low-lying area (Fig. 1). The plain is bounded by the Pollino chain to the north and by the Sila massif and the northern Crati basin to the south and west. From a seismotectonic point of view, Sybaris is located inferences the northeastern Calabrian arc, the tectonic evolution of which is controlled by slow north-northwest/south-southeast convergence between the Eurasian and African–Adriatic continental plates (e.g., Gvirtzmann and Nur, 1999; Argnani, 2000; Jolivet and Faccenna, 2000). Throughout the Calabrian arc, complex dynamics associated with subduction and rollback have produced back-arc extension, widespread uplift, and relative subsidence in the major tectonic basins, including Sibari, where mainly normal seismogenic faults accommodate internal deformation. The interior of the Sibari Plain has a high seismogenic potential, and recently, on July 2010, theMt. Pollino chain area experienced a three-year seismic sequence with magnitudes up to 5.2 (Fig. 1), following 30 years of seismic quiescence. In contrast, low to moderate seismicity characterizes the eastern half of the plain closer to the Ionian Sea, where the archaeological site of Sybaris is located (Fig. 1). Although not well constrained, there is evidence for active compression in this portion of northern Calabria and the Ionian Sea, where mostly strike-slip faults aremapped (e.g., Frepoli and Amato, 2000; Galadini et al., 2001; Pondrelli et al., 2006; Scognamiglio et al., 2009; Comerci et al., 2013; Fig. 1), but significant uncertainty exists on locations, geometry, and age of these faults. The 2700-year long record of history stored in the archaeological site of Sybaris may have recorded the traces of earthquakes that occurred in the area by sealing their effects in the sediments and in the archaeological remains. An archaeoseismic study of the site constitutes a unique means to deepenour knowledge of the seismotectonic of the area. The recognition and characterization of the coseismic deformation affecting the structures of the Sybaris archaeological site is the objective of the present study. To identify past seismic deformation events at Sybaris, we proceeded with (1) a systematic survey of the deformed structures, (2) an analysis of the tectonic deformation, (3) the formulation of a hypothesis for tectonics and earthquakes inferences, and (4) constraints on the timing of the deformation based on archaeological stratigraphy and absolute dating.
    Description: Published
    Description: 245-254
    Description: 2T. Tettonica attiva
    Description: JCR Journal
    Description: restricted
    Keywords: Archaeo-seismology ; Active tectonics ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 6
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    New insights on the strongest historical earthquake in the Pollino region (southern Italy) (2015)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: The Italian seismic catalog (Rovida et al., 2011) portrays a significant gap of seismicity in the Pollino Range area, the southernmost segment of the southern Apennines at the boundary with the Calabrian arc. In this region, the only significant seismic event of the instrumental era occurred in 1998 north of the Pollino Range (Mw 5.6, Fig. 1). No seismic event with intensity greater than VIII on the Mercalli–Cancani–Sieberg (MCS) scale is present in the historical records, whereas strong earthquakes occurred immediately north (1836 M 6.0; 1857 M 7.0) and south (1184 M 6.7; 1836 M 6.2) of the area (Fig. 1). However, geologic data (Bousquet, 1973; Russo and Schiattarella, 1992) have shown clear evidence ofQuaternary faulting along two major normal seismogenic faults, the Pollino and the Castrovillari faults. Paleoseismological data (Michetti et al., 1997;Cinti et al., 1997, 2002) recognized the occurrence of large magnitude events during medieval times along those two faults, but no trace is left of these major events in the historical record. In the case of the Pollino area, the discrepancy between true seismic history and recorded seismic history is due to a combination of a documentary gap of the historical sources (Scionti et al., 2006) and to the low population and scarcity of settlements in the epicentral area (D’Addezio et al., 1995; Cinti et al., 1997). Furthermore, there is the sound possibility that such documentary limitation also might affect moderate (M 5–6) earthquakes, thus providing the opportunity for new assessments that could re-estimate their sizes. Noticeable recent examples of this come from Scionti et al. (2006), with the reestimation to Mw 6.2 of an earthquake that occurred 100 km southeast of the Pollino region, from Tertulliani et al. (2012) for the 1762 earthquake close to L’Aquila, and from Azzaro et al. (2007) for northeastern Sicily. We want to emphasize that there is recent growing interest in the question of reestimating the sizes of historical earthquakes (see Rong et al., 2011; Hough, 2013). Therefore, reducing the uncertainties in the locations and sizes of seismic events for areas like Pollino can be an important contribution toward a clearer picture of the seismic potential and the distribution of earthquake recurrence times that can affect the seismic hazard of a territory. The first attempts at in-depth analyses of the historical seismicity in the Pollino seismic gap date back to the first half of the 1990s (Storia Geofisica Ambiente [SGA], 1994; Valensise et al., 1994; Guidoboni and Mariotti, 1997), whereas more recent developments are by SGA (2000), Camassi and Castelli (2004), and Castelli and Camassi (2005). The seismic histories (the list of earthquakes affecting a site during historic time) of towns and villages of the area (Locati et al., 2011) do not contain earthquakes that occurred before A.D. 1600, neither local nor remote, which could have affected such localities. The oldest traces of earthquakes are associated with the 1638 M 7 event that occurred in central Calabria ∼100 km south of the Pollino area and produced damage in Castrovillari. The more ancient event documented in the study area is the 1693 earthquake, which was listed for the first time in a catalog in 2007 (Guidoboni et al., 2007). In this study, we focus on this latter event, which also appears as the strongest shock in the region and is characterized by a relative scarcity of information and few intensity datapoints. We gathered all potential primary sources of information available for the 1693 earthquake in the attempt to improve its intensity map. We also address two further issues in the reappraisal of the 1693 earthquake: (1) the temporal coincidence between 8 January 1693 Pollino earthquake and its aftershocks and 9–11 January 1693 catastrophic earthquakes of eastern Sicily, along with the consequent quest for a correct attribution of the information regarding the two seismic sequences; and (2) the occurrence in October 2012 (following a sequence of small earthquakes lasting three years) of an Mw 5.3 mainshock, which is by far the strongest event in the instrumental era in the area.
    Description: Published
    Description: 743-751
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: JCR Journal
    Description: restricted
    Keywords: Pollino ; 1693 earthquake ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 7
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    The ShakeMap Atlas for the City of Naples, Italy (2015)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: Naples is one of the most vulnerable cities in the world because it is threatened by several natural and man-made hazards: earthquakes, volcanic eruptions, tsunamis, landslides, hydrogeological disasters, and morphologic alterations due to human interference. In addition, the risk is increased by the high density of population (Naples and the surrounding area are among the most populated in Italy), and by the type and condition of buildings and monuments. In light of this, it is crucial to assess the ground shaking suffered by the city. To create a ShakeMap atlas for the region and to reconstruct the seismic history of the city from historical to recent times, we gather information from the most reliable and complete databases of macroseismic intensity records dating back to the eleventh century. The events felt in Naples cover a time span ranging from 1293 to 1999. The first event (Mw 5.8) was an earthquake in 1293, located in the southern Apennines, at a distance of 100 km from Naples. The most recent event was an earthquake of moderate magnitude in 1999, located beneath Vesuvius (Fig. 1). In the previous release of the macroseismic databases, two additional events associated with the volcanic activity of Vesuvius in 62 and 79 A.D. were included. They are not included in the new release of the databases because they occurred before 1000 A.D., and likewise they have been not included in this atlas because they are too ancient to be incorporated into any time and magnitude window of completeness. For instrumental events (e.g., after 1980), we merge these macroseismic records with strong-motion data. Basically, we integrate information from five Italian databases and catalogs. This gives us the opportunity to explore several sources of information, expanding the completeness of our data set in both time and magnitude. A total of 84 earthquakes have been analyzed. For each event, we compute the shakemap set (Wald et al., 1999; Michelini et al., 2008; Worden et al., 2010) using an ad hoc implementation developed for this application, with (1) specificground-motion prediction equations (GMPEs) accounting for the different attenuation properties in volcanic areas compared with the tectonic ones, and (2) detailed local microzonation to include the site effects. These shakemaps are provided in terms of Mercalli–Cancani–Sieberg intensity (MCS hereinafter) and peak ground acceleration (PGA). For PGA, the maps are provided in terms of median values and 16th and 84th percentiles, to quantify the epistemic uncertainties associated with the ground-motion measurements. In our prospective, the ShakeMap atlas has a dual application. On one hand, it is an important instrument in seismic risk management because it quantifies the level of shaking suffered by a city during its history, and it could be implemented to the quantification of the number of people exposed to certain degrees of shaking (Allen et al., 2009). Intensity data provide the evaluation of the damage caused by earthquakes; the damage is closely connected with the ground shaking, building type, and vulnerability, and it is not possible to separate these contributions. On the other hand, the atlas can be used as starting point for Bayesian estimation of seismic hazard. This technique allows for the merging of the more standard approach adopted, for example, in the compilation of the national hazard map of Italy used in this Bayesian framework as prior mode, with the site-type approach to the purpose of likelihood function (Selva and Sandri, 2013). The site-type technique is based on ground shaking data recorded in a given area; because the majority of earthquakes occurred when no seismometers were available, site data are mainly from macroseismic evaluation, that is, the felt effect is reconstructed from historical documents. The first two sections of the paper describe the databases and catalogs used, and the specific shakemap configuration applied. In the final section, we analyse the completeness of the atlas in terms of time for different magnitude/intensity thresholds, adopting and comparing two different strategies, one based mainly on historical analysis and the other on statistical evaluation.
    Description: Published
    Description: 963-972
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: JCR Journal
    Description: restricted
    Keywords: Shake Map ; Historical Seismology ; Ground Shaking ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 8
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    The AHEAD Portal: A Gateway to European Historical Earthquake Data (2014)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: The description of the seismicity of the European region is today fragmented into an increasing number of earthquake archives, databases, and catalogs related to individual countries or even to part of them. Therefore, the compilation of a comprehensive, European earthquake history requires dealing with a puzzle of partially overlapping, only partially public catalogs, the background of which is compiled according to varied schemes. One of the consequences is that earthquakes in the frontier areas are often interpreted in a conflicting way by the catalogs of the bordering countries. In the framework of the European Commission (EC), 2006–2010 Network of Research Infrastructures for European Seismology (NERIES) Project, the task of Networking Activity 4 (NA4) was defined precisely to conceive and develop solutions to bridge over these differences. NA4 promoted the cooperation among existing national online archives, and contributed establishing new regional online archives compiled according to common standards. As a result, a first release of the distributed European archive of historical earthquake data, for the time-window 1000–1899 and for the large earthquakes, was published in 2010. Special attention was devoted to retrieve the earthquake background information, that is, the results of historical earthquake investigation—referenced to as studies in the following -in terms of a paper, a report, a book chapter, a map, etc. As the most useful studies are those supplying a set of macroseismic data points (MDPs)- that is a list of localities (name and coordinates) with a macroseismic intensity assessment and the related macroseismic scale—a dedicated effort was addressed to make such data available. The Archive of Historical Earthquake Data (AHEAD) distributed archive was improved and updated in the frame of the 2010–2012 EC Project Seismic Hazard Harmonization in Europe (SHARE), Task 3.1 European earthquake database, with the contribution of a number of European institutions. For the time window 1000–1899, it was AHEAD (AHEAD Working Group) that supported the compilation of the SHARE European Earthquake Catalog (SHEEC; Stucchi et al., 2013). This paper describes the AHEAD portal (http://www.emidius.eu/AHEAD/; last accessed March 2014), and how it was conceived to network the local components of the distributed archive. Although local historical macroseismic databases usually supply one set of information for each earthquake, at a European scale an earthquake still might be described by several studies, available from different archives. The AHEAD portal inventories and gives access to multiple sets of information concerning each earthquake, and allows users to get comprehensive information about individual earthquakes, providing the answers to the following questions: 1. which sets of earthquake parameters (time, location, magnitude, magnitude type, maximum intensity, etc.) are available for each earthquake? 2. what is the background information, or supporting material, upon which each set of earthquake parameter determination is based?
    Description: Published
    Description: 727-734
    Description: 2T. Tettonica attiva
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: 4IT. Banche dati
    Description: JCR Journal
    Description: restricted
    Keywords: earthquakes ; earthquake catalogue ; historical seismology ; seismicity ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 9
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    Coseismic deformation and source modeling of the May 2012 Emilia (Northern Italy) earthquakes (2013)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: 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.
    Description: Published
    Description: 645-655
    Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Description: 1.9. Rete GPS nazionale
    Description: 1.10. TTC - Telerilevamento
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: restricted
    Keywords: Earthquake ; CFF analysis ; Tectonic ; geodynamic ; Seismic source ; Northern apennine (Italy) ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 04. Solid Earth::04.06. Seismology::04.06.02. Earthquake interactions and probability ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 05. General::05.01. Computational geophysics::05.01.01. Data processing ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 10
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    Detection of Seismic Signals from Background Noise in the Area of Campi Flegrei: Limits of the Present Seismic Monitoring (2013)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: In the present paper, we will describe the field survey (Fig. 1) and the data analysis of an experiment carried out to put constraints on the magnitude detection threshold in the area of Campi Flegrei. Results show that seismic radiation emitted from VT seismic events at frequency lower than 2 Hz has a high detection threshold (minimum magnitude around 1.5). In the range between 2 and 20 Hz, VT events with magnitudes smaller than about 0.5 have a high probability to be undetected. This result indicates that noise reduction through borehole stations and/or small arrays is essential for an accurate seismic monitoring in the Campi Flegrei area.
    Description: Published
    Description: 190-198
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: restricted
    Keywords: seismic noise ; magnitude detection ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 11
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    Damage Distribution in L’Aquila City (Central Italy) during the 6 April 2009 Earthquake (2013)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: 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.
    Description: Published
    Description: 1543-1553
    Description: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
    Description: JCR Journal
    Description: restricted
    Keywords: l'aquila earthquake ; damage distribution ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 12
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    Ancient and Medieval Earthquakes in the Area of L’Aquila (Northwestern Abruzzo, Central Italy), A.D. 1–1500: A Critical Revision of the Historical and Archaeological Data (2012)
    Seismological Society of America
    Details
    Publication Date: 2012-10-09
    Description: This historical seismology study examines and supplements what is currently known from written sources and archaeological literature about the earthquakes that took place in the area of L’Aquila (central Italy), struck by a damaging earthquake on 6 April 2009 (Mw 6.3), from the ancient Roman period to the late Middle Ages (first through fifteenth century A.D.). The persistence and magnitude of earthquakes in this area has had a strong bearing on the economy and culture of the communities that resided there, a fact borne out by historical accounts. The goal of this revision is to prompt thinking about earthquakes missing from the hazard estimates as well as on return periods for destructive earthquakes in the area. It presents a critical collation of data previously scattered among historical catalogs and writings. Ten earthquakes are examined for their historical and cultural background with a view to highlighting the existence of written sources and explaining both the quality of the available data and the information shortfall. We also show the limits and uncertainty of the information available, coming as it does from tersely written texts giving patchy coverage. This state of knowledge is due either to sources being lost or in certain centuries not being produced (there is a millennium of “lost” earthquakes) and to the present state of historical and archaeological research in this field. The historical and archaeological data we present are often poor/hard to quantify. Yet they are known and hence pose the problem of how to improve the earthquake catalogs and devise new quantitative approaches to hazard estimation based on multi-disciplinary dialog.
    Description: Published
    Description: 1600-1617
    Description: 3.10. Storia ed archeologia applicate alle Scienze della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: Ancient and medieval earthquakes ; L'Aquila area ; archaeological and epigraphic data ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 13
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    Hidden behind the Ranges: How the 13 April 1558 “Sienese” Earthquake Was Put in Its Place (2012)
    Seismological Society of America
    Details
    Publication Date: 2017-04-03
    Description: The 13 april 1558 earthquake was located midway between Siena and Florence (Tuscany) with epicentral intensity VI-VII MCS and magnitude 4.6 by the CPTI Working Group (1999) catalog. The historical data set from which these epicentral parameters were derived is extremely scanty: two low macroseismic intensity data points (Florence and Siena) and vague mentions of "more damage" in the intermediate area. By mean of a targeted archive research, the data set has been very much improved (from 2 to 21 macroseismic intensity data points) and a new set of epicentral parameters has been assessed, turning a comparatively minor damaging event into one with epicentral intensity IX MCS and magnitude 5.8, located in Valdambra, an area with no extant record of seismic activity before this study.
    Description: Published
    Description: 342-351
    Description: JCR Journal
    Description: reserved
    Keywords: Central Tuscany, Relocation of misplaced earthquake ; Archive research, Macroseismic intensity map ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 14
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    Narrow-band, transient signals in Central Apennines, Italy: hints for underground fluid migration? (2012)
    Wiley
    Details
    Publication Date: 2017-04-04
    Description: In this paper we investigate nature and properties of narrow-band, transient seismic signals observed by a temporary array deployed in the Val Tiberina area (central Apennines, Italy). These signals are characterized by spindle-shaped, harmonic waveforms with no clear S-wave arrivals. The first portion of the seismograms exhibits a main frequency peak centred at 4.5 Hz, while the spectrum of the slowly decaying coda is peaked at about 2 Hz. Events discrimination is performed using a matched-filtering technique, resulting in a set of 2466 detections spanning the 2010 January–March time interval. From a plane-wave-fitting procedure, we estimate the kinematic properties of signals pertaining to a cluster of similar events. The repetition of measurements over a large number of precisely aligned seismograms allows for obtaining a robust statistics of horizontal slownesses and propagation azimuths associated with the early portion of the waveforms. The P-wave arrival exhibits horizontal slownesses around 0.1 s km−1, thus suggesting waves impinging at the array almost vertically. Separately, we use traveltimes measured at a sparse network to derive independent constraints on epicentral location. Ray parameters and azimuths are calibrated using slowness measurements from a local, well-located earthquake. After this correction, the joint solution from traveltime inversion and array analysis indicates a source region spanning the 1–3 km depth interval. Considerations related to the source depth and energy, and the occurrence rate which is not related to the daily and weekly working cycles, play against a surface, artificial source. Instead, the close resemblance of these signals to those commonly observed in volcanic environments suggest a source mechanism related to the resonance of a fluid–filled fracture, likely associated with instabilities in the flux of pressurized CO2.
    Description: Published
    Description: 918-928
    Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Description: JCR Journal
    Description: reserved
    Keywords: Fracture and flow ; Earthquake source observations ; Interface waves ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
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  • 15
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    Investigating Rupture Direction for Three 2012 Moderate Earthquakes in Northern Italy from Inversion of Peak Ground-Motion Parameters (2012)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: We investigate the possibility of inferring the dominant horizontalrupture direction for moderate earthquakes from the inversion of peak ground-motion parameters. To this aim, we adopt a technique that was devised and applied to large earthquakes for retrieving both the dominant rupture direction and the surface fault projection to be used with a proper distance metric to refine the ShakeMap computation. In the present paper, the procedure was applied to three moderate earthquakes that occurred in 2012 in Northern Italy three days apart: the M 4.2 Pre-Alpi Venete earthquake on 24 January, the M 4.9 Reggio Emilia earthquake on 25 January, and the M 5.4 Parma earthquake on 27 January. For two of the three analyzed events, the technique identifies a dominant horizontal-rupture direction, which is consistent with the strike directions inferred from the focal mechanisms. For theM 5.4 event, which is a deep (about 61 km) thrust-faulting mechanism earthquake, the inferred dominant rupture direction allows identification of the northeast-dipping plane as the fault plane in accordance with the aftershocks distribution.
    Description: Published
    Description: 2764–2770
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: restricted
    Keywords: Fault directivity ; Peak Ground-Motion Parameters ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
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  • 16
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    The 1762 October 6 earthquake in the Middle Aterno Valley (L'Aquila, Central Italy): new constraints and new insights (2012)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: The effort for reducing the uncertainties in the location and size of historical earthquakes, even moderate-size ones, is not a peripheral issue, as it plays a major role in the distribution of earthquake recurrence times that can affect the maps of seismic hazard of a territory. The L‟Aquila area (Abruzzo, Central Italy) struck by the April 6, 2009 Mw 6.3 seismic event is a typical example of an earthquake-prone region the location of whose historical seismicity needs to be better located. Thanks to a large body of geological, seismological and geodetic evidence the deep source of the 2009 mainshock has been imaged as a ~15 km-long, NW-trending, SWdipping, almost pure normal fault coinciding with the Paganica Fault accepted_Manuscript Click here to download Manuscript: accepted_source_file.doc 2 System at the surface (Fig. 1). Conversely, very few papers have addressed so far the issue of reconstructing the seismic history of the Paganica Fault, charting the relationships between this fault and the adjacent ones, and finding out the causative source for each of the earthquakes listed in the Italian earthquake Catalog (CPTI Working Group, 2004; Rovida et al., 2011).
    Description: Published
    Description: 1068-1077
    Description: 1.11. TTC - Osservazioni e monitoraggio macrosismico del territorio nazionale
    Description: JCR Journal
    Description: open
    Keywords: historical seismology ; 1762 earthquake ; abruzzo ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 17
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    The Uzège (Southeastern France) 22 March 1186 Earthquake Reappraised (2012)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: Uzège, or Pays d’Uzès, is the area surrounding Uzès, a town in the administrative department of Gard (southeastern France). The Languedoc-Roussillon region of France, which Gard belongs to, does not have a high level of local seismicity, though it can affected by large earthquakes originating in the Pyrenees and in Provence. The new seismic zoning of France, issued on 1 May 2011, grades the seismicity of the Gard department as moderate to weak (Plan Séisme 2011). The extant SisFrance (2010) Gard earthquake catalog starts with a shock felt in Uzès in 1186 (intensity and epicentral location unknown), includes only one slightly damaging local earthquake (1946, epicentral intensity 6–7 on the MSK- 1964 scale), and associates the maximum macroseismic intensity on record in the area with an extra-regional event, the 1909 Lambesc (Provence) earthquake, the strongest event located in metropolitan (i.e., mainland) France during the last century (epicentral intensity 8–9 on the MSK-1964 scale). But this picture could be incomplete. A recent study of the Uzès-Nîmes Roman aqueduct, Volant et al. (2009), has hypothesized a connection between some archaeological evidence of damage undergone by a section of this artifact and the possible occurrence of one or maybe even two major earthquakes (M ≥ 6, type of magnitude undefined) in the 3rd or 4th century AD. We are now able to show that Uzège was the setting of the most significant local earthquake of the last millennium, though the actual import of this event has remained ignored until now, owing to the lack of historical evidence in situ. Thanks to the accidental discovery of a previously unknown contemporary source, preserved very far from the place where it was originally written, it is now possible to significantly revise the 1186 earthquake dataset by providing reliable evidence of relevant damage incurred by settlements less than 10 km northeast of Uzès.
    Description: Published
    Description: 604-614
    Description: 3.10. Storia ed archeologia applicate alle Scienze della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: Uzège, SE France, historical seismology, historical research ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
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  • 18
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    In Search of the Predecessors of the 2011 Van (Turkey) earthquake (2012)
    Seismological Society of America
    Details
    Publication Date: 2022-09-08
    Description: [The Mw 7.2 earthquake of 23 October 2011 struck an area of Eastern Anatolia with a long historical record and a long earthquake history. The earthquake occurred in a region of rather complex tectonics resulting from the collision of the Arabian and Eurasian continental plates. The 23 October 2011 earthquake caused heavy damage to Van and several towns and villages around Lake Van, in the districts of Van and Ercis. It was followed by several aftershocks and another strong event (Mw 5.7) that occurred on 9 November 2011, causing further damage and casualties. Though the seismicity of the area is described by some regional parametric earthquake catalogs and has been the subject of several studies, no earthquake with a magnitude equivalent to the 2011 one is reported by the catalog in the area of the 2011 earthquake; so, apparently, there are no predecessors of this earthquake. However, two questions arise: a) could some events located close to Van have been underestimated or mislocated, as frequently happens with poorly known events?, and b) are there gaps in the earthquake history of the Van region? As for the first question, we have not found earthquakes which could, in principle, be underestimated and/or mislocated by the catalog and that could be re-located in the area of the October 2011 earthquake with a comparable magnitude. The earthquake history shows gaps between 1275 and 1646, and later between 1715 and 1834, gaps which have further investigated on the occasion of the preparation of this paper. In conclusion, nothing can be said about earthquakes in the time-window before 1646 in the region east of Lake Van. After that year, no prominent candidate earthquake appears as a possible twin of the 23 October 2011 event.]
    Description: Published
    Description: 855-862
    Description: 3.10. Storia ed archeologia applicate alle Scienze della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: Historical seismology, Lake Van (Turkey) ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
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  • 19
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    The True Case of the 1276 Fake Earthquake (2011)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: The tangled case history of the 1276 mislocated earthquake is presented in this paper as a paradigmatic one, to explain how the background information on an earthquake is retrieved and specifically to show how it came to light that a good-quality historical earthquake record had been twisted, wrongly interpreted, and eventually included in earthquake catalogs with an incorrect date and location.
    Description: Published
    Description: 111-114
    Description: 3.10. Storia ed archeologia applicate alle Scienze della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: 1276 fake earthquake ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
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  • 20
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    Seismic Network Evaluation through Simulation: An Application to the Italian National Seismic Network (2011)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: A properly organized seismic network is a valuable tool for monitoring seismic zones and assessing seismic hazards. In this paper we propose a new method (seismic network evaluation through simulation, SNES) to evaluate the performance of hypocenter location of a seismic network. The SNES method gives, as a function of magnitude, hypocentral depth, and confidence level, the spatial distribution of the number of active stations in the location procedure and their relative azimuthal gaps, along with confidence intervals in hypocentral parameters. The application of the SNES method also permits evaluation of the magnitude of completeness (MC), the background noise levels at the stations, and assessment of the appropriateness of the velocity model used in location routine. Italy sits on a tectonically active plate boundary at the convergence of the Eurasian and African lithospheric plates and has a high level of seismicity. In this paper, we apply the SNES method to the Italian National Seismic Network (Rete Sismica Nazionale Centralizzata dell’Istituto Nazionale di Geofisica e Vulcanologia, RSNC– INGV) which has monitored Italian seismicity since the early 1980s, following the destructive 1980 Irpinia earthquake. In recent years, the RSNC–INGV has grown significantly. In fact, in February 2010, it received signals from 305 seismic stations, 258 with wideband three-component sensors. We constructed SNES maps for magnitudes of 1.5, 2, 2.5, and 3, fixing the hypocentral depth at 10 km and the confidence level at 95%. Through the application of the SNES method, we show that the RSNC–INGV provides the best monitoring coverage in the Apennine Mountains with errors that for M 2, are less than 2 and 4 km for epicenter and hypocentral depth, respectively. At M 2.5 this seismic network is capable of constraining earthquake hypocenters to depths of about 150 km for most of the Italian Peninsula. This seismic network provides a threshold of completeness down to M 2 for almost the entire Italian territory.
    Description: Published
    Description: 1213-1232
    Description: 2.5. Laboratorio per lo sviluppo di sistemi di rilevamento sottomarini
    Description: JCR Journal
    Description: reserved
    Keywords: Italian National Seismic Network ; Magnitude of Completeness ; Location Performance ; Seismic Noise ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
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  • 21
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    Developing Seismogenic Source Models Based on Geologic Fault Data (2011)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: Calculating seismic hazard usually requires input that includes seismicity associated with known faults, historical earthquake catalogs, geodesy, and models of ground shaking. This paper will address the input generally derived from geologic studies that augment the short historical catalog to predict ground shaking at time scales of tens, hundreds, or thousands of years (e.g., SSHAC 1997). A seismogenic source model, terminology we adopt here for a fault source model, includes explicit three-dimensional faults deemed capable of generating ground motions of engineering significance within a specified time frame of interest. In tectonically active regions of the world, such as near plate boundaries, multiple seismic cycles span a few hundred to a few thousand years. In contrast, in less active regions hundreds of kilometers from the nearest plate boundary, seismic cycles generally are thousands to tens of thousands of years long. Therefore, one should include sources having both longer recurrence intervals and possibly older times of most recent rupture in less active regions of the world rather than restricting the model to include only Holocene faults (i.e., those with evidence of large-magnitude earthquakes in the past 11,500 years) as is the practice in tectonically active regions with high deformation rates. During the past 15 years, our institutions independently developed databases to characterize seismogenic sources based on geologic data at a national scale. Our goal here is to compare the content of these two publicly available seismogenic source models compiled for the primary purpose of supporting seismic hazard calculations by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) and the U.S. Geological Survey (USGS); hereinafter we refer to the two seismogenic source models as INGV and USGS, respectively. This comparison is timely because new initiatives are emerging to characterize seismogenic sources at the continental scale (e.g., SHARE in the Euro- Mediterranean, http://www.share-eu.org/; EMME in the Middle East, http://www.emmegem. org/) and global scale (e.g., GEM, http://www.globalquakemodel.org/; Anonymous 2008). To some extent, each of these efforts is still trying to resolve the level of optimal detail required for this type of compilation. The comparison we provide defines a common standard for consideration by the international community for future regional and global seismogenic source models by identifying the necessary parameters that capture the essence of geological fault data in order to characterize seismogenic sources. In addition, we inform potential users of differences in our usage of common geological/seismological terms to avoid inappropriate use of the data in our models and provide guidance to convert the data from one model to the other (for detailed instructions, see the electronic supplement to this article). Applying our recommendations will permit probabilistic seismic hazard assessment codes to run seamlessly using either seismogenic source input. The USGS and INGV database schema compare well at a first-level inspection. Both databases contain a set of fields representing generalized fault three-dimensional geometry and additional fields that capture the essence of past earthquake occurrences. Nevertheless, there are important differences. When we further analyze supposedly comparable fields, many are defined differently. These differences would cause anomalous results in hazard prediction if one assumes the values are similarly defined. The data, however, can be made fully compatible using simple transformations.
    Description: USGS Senior Scientist In Residence
    Description: Published
    Description: 519-525
    Description: 3.2. Tettonica attiva
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
    Description: JCR Journal
    Description: open
    Keywords: Active fault ; fault source ; database ; seismic hazard ; Italy ; USA ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk ; 04. Solid Earth::04.07. Tectonophysics::04.07.04. Plate boundaries, motion, and tectonics ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
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  • 22
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    Tsunami early warning using earthquake rupture duration and P-wave dominant-period: the importance of length and depth of faulting (2011)
    Wiley
    Details
    Publication Date: 2017-04-03
    Description: After an earthquake, rapid, real-time assessment of hazards such as ground shaking and tsunami potential is important for early warning and emergency response. Tsunami potential depends on sea floor displacement, which is related to the length, L, width, W, mean slip, D, and depth, z, of earthquake rupture. Currently, the primary discriminant for tsunami potential is the centroid-moment tensor magnitude, MwCMT, representing the seismic potency LWD, and estimated through an indirect, inversion procedure. The obtained MwCMT and the implied LWD value vary with the depth of faulting, assumed earth model and other factors, and is only available 30 min or more after an earthquake. The use of more direct procedures for hazard assessment, when available, could avoid these problems and aid in effective early warning. Here we present a direct procedure for rapid assessment of earthquake tsunami potential using two, simple measures on P-wave seismograms – the dominant period on the velocity records, Td, and the likelihood that the high-frequency, apparent rupture-duration, T0, exceeds 50-55 sec. T0 can be related to the critical parameters L and z, while Td may be related to W, D or z. For a set of recent, large earthquakes, we show that the period-duration product TdT0 gives more information on tsunami impact and size than MwCMT and other currently used discriminants. All discriminants have difficulty in assessing the tsunami potential for oceanic strike-slip and back-arc or upper-plate, intraplate earthquake types. Our analysis and results suggest that tsunami potential is not directly related to the potency LWD from the “seismic” faulting model, as is assumed with the use of the MwCMT discriminant. Instead, knowledge of rupture length, L, and depth, z, alone can constrain well the tsunami potential of an earthquake, with explicit determination of fault width, W, and slip, D, being of secondary importance. With available real-time seismogram data, rapid calculation of the direct, period- duration discriminant can be completed within 6-10 min after an earthquake occurs and thus can aid in effective and reliable tsunami early warning.
    Description: In press
    Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Description: JCR Journal
    Description: open
    Keywords: Earthquake dynamics ; Earthquake source observations ; Seismic monitoring ; Body waves ; Early warning ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
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  • 23
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    Multiplet Focal Mechanisms from Polarities and Relative Locations: The Iznajar Swarm in Southern Spain (2010)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: In April 1998, a swarm of 1800 microearthquakes near the village of Iznajar (southern Spain) was recorded at the Granada basin short-period seismic network. Focal mechanisms from local P-wave polarities are poorly constrained and cannot characterize the seismotectonics of the series. Here we combine polarity information and multiplet relocation to address this issue. We use waveform cross correlation on P and S arrivals to identify events with highly similar seismograms, group our detections into multiplet clusters, and invert the cross-correlation time delays to obtain precise relative locations. Relative locations have errors of several tens to a few hundreds of meters horizontally and vertically, and define strike and dip of active fault patches with an accuracy of 20°–30°. We introduce the multiplet fault plane orientations into focal mechanism inversion, now yielding mostly well-constrained solutions, in addition to resolving the nodal plane symmetry. We observe mainly north-south left-lateral strike-slip faulting and a few north-northwest–south-southeast normal faulting solutions, illustrating the kinematic complexity of the swarm, and pointing to a local deformation style different from the nearby Granada basin.
    Description: Published
    Description: 3421-3429
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: reserved
    Keywords: Fault plane solution ; Precise location ; Seismic swarm ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
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  • 24
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    Analysis of Earthquake Damage to Ancient Buildings on the San Raineri Peninsula, Messina, Sicily (2010)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: A study aimed to shed some light on building collapse caused by the strongest earthquakes in the San Raineri Peninsula (Messina) is here reported. Although a compilation of structurally damaged buildings is widely reported in historical sources, the interpretation of seismic collapse has often been doubtful or ambiguous. We therefore performed an exhaustive and detailed review of seismic effects caused by the 1783 and 1908 earthquakes on the peninsula buildings. Geological and geotechnical data were also collected on the peninsula. The results of boring data reveal high seismic vulnerability for the peninsula in some areas. The study shows that the ancient buildings were damaged by settlement due to soil liquefaction rather than by seismic shaking of the large walls. The obtained results show that further investigations must be carried out in this area for a correct town planning of the peninsula.
    Description: Published
    Description: 2067-2079
    Description: 3.10. Storia ed archeologia applicate alle Scienze della Terra
    Description: JCR Journal
    Description: restricted
    Keywords: historical earthquakes ; soil liquefaction ; San Raineri Peninsula ; Messina ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
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  • 25
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    On the Stability and Reproducibility of the Horizontal-to-Vertical Spectral Ratios on Ambient Noise: Case Study of Cavola, Northern Italy (2010)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: Horizontal-to-vertical spectral ratios using ambient noise (HVNSR) are commonly used in site effects studies. In the practice, many operators assume stability over time of HVNSR and base their analyses on few very short time windows. The availability of a long period of continuous microtremor recording allowed us to analyze three months of data coming from a dense array experiment performed at Cavola, a village in northern Apennines. This condition offers a good opportunity to check the validity of the stability assumption and to investigate variations of the local ambient noise wave-field composition. The Cavola site is characterized by landslide sediments over stiffer materials with a moderate impedance contrast and by a complex morphology. An intense industrial activity in the village contributes to the generation of seismic noise. After identifying this noise source in the time series, we evaluate its effects on HVNSR. The results indicate that the spectral peak of HVNSR varies in amplitude and frequency, posing a warning about stability in time. Analyzing the spectra we identify the anthropic activity as responsible for changes in the composition of the noise wave field. These variations affect HVNSR, including peak frequency and also ground-motion polarization.
    Description: Published
    Description: 1263-1275
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: restricted
    Keywords: noise measurements ; Rayleigh waves ; polarization ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
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  • 26
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    Using WiMAX to improve volcano monitoring during an emergency: a feasibility study of the WEIRD system applied to the Campi Flegrei volcanic area scenario (southern Italy) (2009)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: IEEE Standard for Local and Metropolitan Area Networks (hereafter IEEE 802.16; online at http://standards.ieee.org/getieee802/802.16.html) is one of the most promising mobile and fixed broadband wireless access technologies for next-generation all-IP networks in the 3.5 GHz band (European spectrum profile). Commonly known as Universal WiMAX (worldwide inter-operability for microwave access), this access technology reaches a high bit rate and covers large areas with a single base station, making it possible to offer connectivity to end users in a cost-effective way. A further useful property of the WiMAX technology is that the transmission can be used both in line-of-sight (LOS) and non-line-of-sight (NLOS) environments, allowing highly feasible communications (WiMAX Forum 2004). Thanks to these features, IEEE 802.16 opens the way to the use of wireless technologies in the environmental monitoring of areas such as seismic and volcanic zones.
    Description: European Community’s Sixth Framework Programme, Contract no. IST-034622-IP
    Description: Published
    Description: 411-419
    Description: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: WiMAX ; volcano monitoring ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.06. Seismology::04.06.10. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 27
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    The Paganica Fault and surface coseismic ruptures caused by the 6 april 2009 earthquake (L’Aquila, central Italy) (2009)
    Seismological Society of America
    Details
    Publication Date: 2022-06-14
    Description: On 6 April 2009, at 01:32 GMT, an Mw 6.3 seismic event hit the central Apennines, severely damaging the town of L’Aquila and dozens of neighboring villages and resulting in approximately 300 casualties (Istituto Nazionale di Geofisica e Vulcanologia, http://www.ingv.it; MedNet, http://mednet.rm.ingv.it/proce- dure/events/QRCMT/090406_013322/qrcmt.html). This earth- quake was the strongest in central Italy since the devastating 1915 Fucino event (Mw 7.0). The INGV national seismic net- work located the hypocenter 5 km southwest of L’Aquila, 8–9 km deep. Based on this information and on the seismotectonic framework of the region, earthquake geologists traveled to the field to identify possible surface faulting (Emergeo Working Group 2009a, 2009b). The most convincing evidence of pri- mary surface rupture is along the Paganica fault, the geometry of which is consistent with seismological, synthetic aperture radar (SAR) and GPS data. Investigation of other known nor- mal faults of the area, i.e., the Mt. Pettino, Mt. San Franco, and Mt. Stabiata normal faults suggested that these structures were not activated during the April 6 shock (Emergeo Working Group 2009a, 2009b). In this report, we first describe the seismotectonic frame- work of the area, and then we present the field information that supports the occurrence of surficial displacement on the Paganica fault.
    Description: Published
    Description: 940-950
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: open
    Keywords: Surface coseismic ruptures ; Paganica Fault ; earthquake ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
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  • 28
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    Characteristics of Ambient Noise Cross-Correlations in Northern Italy within the 0.1- to 0.6-Hz Frequency Range (2008)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: In this note, we investigate the characteristics of ambient noise cross-correlations for station pairs in northern Italy, considering the secondary microseism bandwidth (0.1-0.6 Hz). The preliminary analysis that we performed exploiting the available continuous recording in the investigated area, agrees with the recent results of Pedersen et al. (2007): the directionality of the noise signal cannot be disregarded when the group velocity is estimated in the range 0.1-0.6 Hz and the selection of the path orientation for tomography must be carefully performed. In particular, while the favourable directions with respect to microseisms generated along the Atlantic coasts of France, Norway and British Islands cover a quite wide azimuthal range (from about 270N to 5N), allowing us to reliably estimate the fundamental mode Rayleigh group velocity for paths in the Alps (about 2.7 km/s), more care must be taken when the microseisms are generated in the Mediterranean Sea. In that case, different locations of the generating areas of microseisms could provide biased estimates of the group velocity due to differences between the true and the apparent velocity of propagation between the stations.
    Description: Published
    Description: 1389-1398
    Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Description: JCR Journal
    Description: reserved
    Keywords: microseisms ; ambient noise ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
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  • 29
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    A comparison of sea floor and on land seismic ambient noise in the Campi Flegrei caldera (Southern Italy) (2008)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: The Campi Flegrei (southern Italy) is one of the most active calderas in the world. This caldera is characterized by episodes of slow vertical ground movement, called bradyseism. With several hundred thousand people living within its borders, this area is in a high-risk category should there be an eruption. The seismological monitoring system in the Campi Flegrei is based on nine seismic stations, eight of which are equipped with short-period seismometers (1 Hz), and one with a broadband seismometer (60 sec–50 Hz). While all of the seismic stations are located on land, part of the seismic activity occurs in the undersea area of the Pozzuoli Gulf (Campi Flegrei), where there are no seismic stations. This gap in the data coverage produces a biased and incomplete image of the volcanic area.We carried out an experiment in the Pozzuoli Gulf with the installation of two broadband seismic stations on the seafloor with remote and continuous data acquisition for a duration of 31 days between January and March 2005. Using the data acquired, we have computed the power spectral density (PSD) to characterize the background seismic noise, and to evaluate the true noise variation, we have generated the seismic noise probability density functions from the computed PSD curves. The results of our analysis show that the broadband seismic noise is high when compared with the Peterson noise model (land model), but for periods less than 0.3 sec, the seismic noise on the seafloor is lower than the recordings on land over the same period range. The last bradyseismic crisis (1982–1984) highlights the importance of this frequency range, where most of the spectral content of the recorded earthquakes was observed. Finally, we evaluate the detection threshold of a new seismic station located on the seafloor of the Campi Flegrei caldera considering the characteristics of the local seismicity. This analysis shows that the detection threshold for the sea-floor stations (Mw ∼ 0:2) is less than that for land stations (Mw ∼ 0:8).
    Description: Published
    Description: 2962–2974
    Description: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Campi Flegrei Caldera ; Sea-Floor and On-Land Seismic ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 30
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    Rise and fall of a hypothesized seismic gap: source complexity in the 16 December 1857, Southern Italy earthquake (Mw 7.0) . (2008)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: On 16 December 1857, a strong earthquake (M ∼7) struck a large portion of the southern Apennines about 150 km southeast of Naples. The earthquake was thoroughly investigated by Irish engineer Robert Mallet, who wrote an extensive report that is still regarded as a landmark in observational seismology. Because of the concentration of damage in the High Agri valley, and contrary to Mallet’s own findings, for many years the earthquake was referred to as the “Val d’Agri earthquake” and was believed by most investigators to have ruptured the 20–25-km normal fault lying beneath this intermontane basin. The magnitude of the earthquake, however, and evidence for earthquake complexity suggest that the true rupture length has been so far underestimated. We contend that the 1857 earthquake ruptured in a cascade fashion two adjacent and relatively well-known faults: first the smaller Melandro–Pergola fault, commonly believed to represent a seismic gap between the causative faults of the 1857 and of the 1980 Irpinia (Mw 6:9) earthquakes; and then the larger Agri valley fault proper. Contemporary chronicles reported a time lapse of 2–3 min between the two ruptures, thus effectively making them two independent shocks. The rupture must have proceeded unilaterally from the northwestern edge of the Melandro–Pergola fault, where Mallet placed the earthquake epicenter, thus explaining the concentration of damage—and attention by rescue crews and subsequent investigators—in the southeastern portion of the High Agri valley.
    Description: This work was funded by the project Assessing the Seismogenic Potential and the Probability of Strong Earthquakes in Italy, funded by the Italian Civil Defense Department within the 2004–2006 agreement with the Istituto Nazionale di Geofisica e Vulcanologia grant to P. Burrato.
    Description: Published
    Description: 139-148
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: partially_open
    Keywords: 1857 Basilicata earthquake ; southern Italy ; Val d'Agri ; seismic gap ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 31
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    Real-time evolutionary earthquake location for seismic early warning (2008)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: An effective early-warning system must provide probabilistic estimates of the location and size of a potentially destructive earthquake within a few seconds after the event is first detected. In this work we present an evolutionary, real-time location technique based on an equal differential time (EDT) formulation and a probabilistic approach for describing the hypocenter estimation. The algorithm, at each timestep, relies on the information from triggered arrivals and not-yet-triggered stations. With just one recorded arrival, the hypocentral location is constrained by the Voronoi cell around the first triggering station constructed using the travel times to the not-yet-triggered stations.With two or more triggered arrivals, the location is constrained by the intersection of the volume defined by the Voronoi cells for the remaining, not-yet-triggered stations and the EDT surfaces between all pairs of triggered arrivals. As time passes and more triggers become available, the evolutionary location converges to a standard EDT location. Synthetic tests performed using the geometry of the Irpinia seismic network, southern Italy (ISNet), and the simulation of an evolutionary location for the 2000 Mw 6:6 Western Tottori, Japan, earthquake indicate that when a dense seismic network is available, reliable location estimates suitable for early-warning applications can be achieved after 1–3 sec from the first event detection. A further simulation with an Mw 6:7 southern Greece earthquake shows that at a regional scale, the real-time location can provide useful constraints on the earthquake position several seconds before a non-real-time algorithm. Finally, we show that the robustness of the algorithm in the presence of outliers can be effectively used to associate phase arrivals coming from events occurring close in time, and we present a preliminary algorithm for event detection.
    Description: Published
    Description: 1482–1494
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: Early warning ; earthquake location ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
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  • 32
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    Unveiling the Sources of the Catastrophic 1456 Multiple Earthquake: Hints to an Unexplored Tectonic Mechanism in Southern Italy (2007)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: We revisited data related to the 1456 seismic crisis, the largest earthquake to have ever occurred in peninsular Italy, in search of its causative source(s). Data about this earthquake consist solely of historical reports and their intensity assessment. Because of the age of this multiple earthquake, the scarcity and sparseness of the data, and the unusually large damage area, no previous studies have attempted to attribute the 1456 events to specific faults. Existing analytical methods to identify a likely source from intensity data also proved inappropriate for such a sparse dataset, since historical evidence suggests that the cumulative damage pattern contains at least three widely separated events. We subdivided the 1456 damage pattern into three independent mesoseismal areas; each of these areas falls onto east–west tectonic trends previously identified and marked by deep (〉10 km) right-lateral slip earthquakes. Based on this evidence we propose (1) that the 1456 events were generated by individual segments of regional east–west structures and are evidence of a seismogenic style that involves oblique dextral reactivation of east–west lower crustal faults; (2) that each event may have triggered subsequent but relatively distant events in a cascade fashion, as suggested by historical accounts; hence (3) that the 1456 sequence reveals a fundamental but unexplored mechanism of tectonic deformation and seismic release in southern Italy. This style dominates the region that lies between the northwest–southeast system of large extensional faults straddling the crest of the southern Apennines and the buried outer front of the chain. Although the quality of the available information concerning the 1456 earthquake is naturally limited, we show that the overlap of the damage distribution, the orientation and characteristics of regional tectonic structures, the seismicity patterns, and the focal mechanisms all concur with our interpretations and would be difficult to justify otherwise.
    Description: Published
    Description: 725-748
    Description: JCR Journal
    Description: open
    Keywords: historical seismicity ; macroseismic data ; seismogenic faults ; southern Italy ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
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  • 33
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    The Potential for Earthquake Early Warning in Italy Using ElarmS (2007)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: The new Italian National Seismic Network (INSN) is a dense network of broadband stations deployed for monitoring Italian seismicity. The network consists of 250 stations with a typical station spacing of !40 km. Earthquake early warning is the rapid detection of an event in progress, assessment of the hazard it poses, and transmission of a warning ahead of any significant ground motion. We explore the potential for using the INSN real-time network for the purpose of earthquake early warning. We run the ElarmS early warning methodology off-line using a data set of more than 200 events with magnitudes between 2.5 and 6.0. A scaling relation for magnitude determination from the dominant period of the first seconds of signal following the P onset is developed from the data set. The standard deviation in the magnitude estimates using this approach is 0.4 magnitude units, and all event magnitude estimates are within !0:75 magnitude units of the true magnitude. Given the existing distribution of seismic stations it takes an average of 10 sec after event initiation before the P wave has been detected at four stations. If we require a detection at four stations before issuing the first alert, then the blind zone, within which no warning would be available, has a radius of !37 km. The ElarmS methodology can provide a warning earlier than this but with a greater uncertainty. An assessment of past damaging earthquakes across Italy shows that applying ElarmS with the existing seismic network could provide warning to population centers in repeats of past events. For example, in a repeat of the 1980 Irpinia earthquake Naples could receive an !15- sec warning. The variations in the size of the blind zone and warning times for different regions can be used as a guide to selecting strategic locations for future station deployments.
    Description: Published
    Description: 495-503
    Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Description: JCR Journal
    Description: reserved
    Keywords: Early Warning ; Earthquake Location ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
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  • 34
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    An Improved Method for the Recognition of Seismic Families: Application to the Garfagnana-Lunigiana Area, Italy (2007)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: With the aim to find a more objective way to detect seismic families, we applied a series of successive steps to constrain the results of a waveform similarity analysis. The evaluation of similarity was carried out on the waveforms recorded in the period 1999–2003 by the stations operating in the Garfagnana area, located in northern Tuscany (Italy). The algorithm is based on the cross-correlation technique applied in a process that overcomes the limit of one order of magnitude between events to be compared through a bridging technique. In practice, if two couples of events (A, B) and (B, C), each exceeding the correlation threshold, share a common quake (B), then all three events are attributed to the same family even if the match between A and C is below a value chosen as a reference for similarity. To avoid any subjective choice of threshold for cross-correlation values, the results from the computation algorithm are submitted to a routine that gives increasing reliability to them if they are confirmed by the three components of the seismogram and if the number of families detected by each station is confirmed by more recordings. This latter constraint is made possible by the geometry of the recording network, with interdistances between stations of the order of 40–50 km. The process finally leads to the recognition of 27 families detected and confirmed by, on average, 3 stations that represent 40% of the recording capabilities. Since the performances of the recording network have been very odd in the past, especially in the early years of operation, the reliability of the detection is much higher, as in most cases the stations that detected the families were the only ones to be effectively recording. The methodology proved to be more efficient than other methods applied in the past; moreover, the results could be probably improved even more if, instead of doing a one-run process, it would be borne as a trial-and-error approach.
    Description: Published
    Description: 1903-1915
    Description: JCR Journal
    Description: reserved
    Keywords: Seismicity ; multiplets ; seismic families ; seismic sequences ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
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  • 35
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    Repeating Earthquakes as Low-Stress-Drop Events at a Border between Locked and Creeping Fault Patches (2005)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: The source of repeating earthquakes on creeping faults is modeled as a weak asperity at a border between much larger locked and creeping patches on the fault plane. The x^(-1/2) decrease in stress concentration with distance x from the boundaryis shown to lead directly to the observed scaling 〈T〉~〈M0〉^(1/6) between the average repeat time and average scalar moment for a repeating sequence. The stress drop in such small events at the border depends on the size of the large locked patch. For a circular patch of radius R and representative fault parameters, Dr = 7.6(m/R)3/5 MPa, which yields stress drops between 0.08 and 0.5 MPa (0.8–5 bars) for R between 2 km and 100 m. These low stress drops are consistent with estimates of stress drop for small earthquakes based on their seismic spectra. However, they are orders of magnitude smaller than stress drops calculated under the assumption that repeating sources are isolated stuck asperities on an otherwise creeping fault plane, whose seismic slips keep pace with the surrounding creep rate. Linear streaks of microearthquakes observed on creeping fault planes are trivially explained by the present model as alignments on the boundaries between locked and creeping patches.
    Description: NSF grants NSF-EAR-9902901 (CGS) and EAR-9805182 (JRR)
    Description: Published
    Description: 532-537
    Description: open
    Keywords: 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
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    Type: article , article
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  • 36
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    Small-aperture Array for Seismic Monitoring of Mt.Vesuvius (2005)
    Seismological Society of America
    Details
    Publication Date: 2017-04-04
    Description: A small aperture quadripartite seismic array was installed on the south-east flanks of Mt. Vesuvius about 1 km far from the crater axis, in order to improve the seismic monitoring of this active volcano. The array has the following main purposes: i) to discriminate natural-source generated signals by artificial-source-generated signals; ii) to detect and track the source of possible Long Period (LP) events; iii) to detect coherent phases in the low frequency noise that may be related to magma movements (tremor insurgence). In addition, the array greatly helps in locating the seismic signals produced by blasts (both in land and sea), allowing a fast discrimination of possible natural long period (LP) quakes. The array is also an useful tool for retrieving the kinematic properties of the wavefield associated to volcano-tectonic (VT) earthquakes (more than 99% of the whole natural seismicity) and to all the other transients which are routinely observed(landslides, artificial blasts). We also use the array to investigate if correlated signals are present in the background noise (insurgence of volcanic tremor). The main result obtained during this first year of observation is that one LP was clearly recognized in the background seismicity at Mt. Vesuvius.
    Description: Published
    Description: 344-355
    Description: open
    Keywords: Volcano monitoring ; Array techniques ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
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  • 37
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    Automatic versus manual model differentiation to compute sensitivities and solve non-linear inverse problems (2002)
    3
    In:  Computers and Geosciences, Münster, 3, vol. 28, no. 45, pp. 309-326, pp. L11609, (ISBN 0-471-26610-8)
    Details
    Publication Date: 2002
    Keywords: Inversion ; Data analysis / ~ processing ; Non-linear effects ; Discrimination ; C&G
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    BIBLIOGRAPHY SEISMOLOGY
  • 38
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    The solution of linear equations by the conjugate gradient method (1967)
    Wiley
    In:  Mathematical Methods for Digital Computers, Volume 1, Sapporo, Japan, Wiley, vol. 17, no. 16, pp. 211-236, (ISBN 0080419208)
    Details
    Publication Date: 1967
    Keywords: Inversion
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  • 39
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    Die Lösung linearer Gleichungen nach der Methode der konjugierten Gradienten (1967)
    Wiley
    In:  Mathematische Methoden für Digitalrechner, Sapporo, Japan, Wiley, vol. 1, no. 16, pp. 106-126, (ISBN 0080419208)
    Details
    Publication Date: 1967
    Keywords: Inversion
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