The April 6, 2009, Mw 6.3, L'Aquila sequence: weak-motion and strong-motion data recorded by the RAIS temporary stations

The aim of this study is the sharing of waveforms recorded by several Istituto Nazionale di Geofisica e Vulcanologia (INGV) temporary stations (managed by the Milan-Pavia section; INGV MI-PV). These stations were installed after the April 6, 2009, Mw 6.3, L'Aquila earthquake (central Italy). The work synthesizes the activities conducted in the field by the INGV MI-PV working group over the three months following the mainshock. The field activities were developed in four different phases that were defined according to their time periods. Starting from April 7, 2009, for the first phase, the temporary stations were installed in correspondence with the more damaged areas. The scope was to record the strongest aftershocks in the days that followed the mainshock. In this phase, the stations were composed of a six-component acquisition system that was coupled with both a weak-motion and a strong-motion sensor. After the first month, the last three phases of installation investigated the seismic responses of sites located in the epicentral area, involving villages within a radius of about 20 km from the epicenter of the April 6 mainshock. In this way, over four specific time-period phases, the stations were installed in sites with different lithological and geomorphological conditions. The instruments worked from April 7 to July 14, 2009; in this period, 9,155 aftershocks (134,262 accelerometric waveforms and 133,242 velocimetric waveforms), with ML ≤5.3 were recorded. This study describes the dataset of these earthquake waveforms recorded with both velocity and acceleration transducers. Selected waveforms are available through ftp://ftp.mi.ingv.it/download/RAIS-TS_rel01/, with their corresponding information concerning instrumental characteristics, installation sites, and earthquakes recorded

Real Time acquisition and processing of strong motion data in Northern Italy: the RAIS network.

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

Long-range dependence in earthquake-moment release and implications for earthquake occurrence probability

Since the beginning of the 1980s, when Mandelbrot observed that earthquakes occur on 'fractal' self-similar sets, many studies have investigated the dynamical mechanisms that lead to self-similarities in the earthquake process. Interpreting seismicity as a self-similar process is undoubtedly convenient to bypass the physical complexities related to the actual process. Self-similar processes are indeed invariant under suitable scaling of space and time. In this study, we show that long-range dependence is an inherent feature of the seismic process, and is universal. Examination of series of cumulative seismic moment both in Italy and worldwide through Hurst's rescaled range analysis shows that seismicity is a memory process with a Hurst exponent H 48 0.87. We observe that H is substantially space-and time-invariant, except in cases of catalog incompleteness. This has implications for earthquake forecasting. Hence, we have developed a probability model for earthquake occurrence that allows for long-range dependence in the seismic process. Unlike the Poisson model, dependent events are allowed. This model can be easily transferred to other disciplines that deal with self-similar processe

ISMD, a Web Portal for Real-Time Processing and Dissemination of INGV Strong-Motion Data

In Italy, strong-motion monitoring started in the early 1970s, when the Rete Accelerometrica Nazionale (RAN, the Italian National Strong Motion Network; http://www.protezionecivile. gov.it/jcms/it/ran.wp;seeData and Resources for a complete listing of all websites listed in this article) was designed and installed by the Agenzia Nazionale per le NuoveTecnologie, l’Energia e lo Sviluppo Economico Sostenibile (ENEA) and ENEL (an Italian power company). The aim was to evaluate the seismic risk in connection with the construction of nuclear power plants. Since 1997, the RAN (Gorini et al.,2010) has been run by the Dipartimento della Protezione Civile (DPC). At present, the RAN includes about 500 digital strong-motion stations. The contribution of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) to Italian strong-motion monitoring started some years later. Through the 2004–2006 agreement between the INGV and the DPC (Strong-Motion Stations Project), the INGV began the phase of strong-motion monitoring (Augliera et al., 2010, 2011). Since 2006, a complete renewal of the (velocimetric) Rete Sismica Nazionale (RSN; Amato and Mele, 2008) was made by installing accelerometers to sites where broadband RSN velocimeters were already present. Altogether, the current∼150 high-dynamics digital strong-motion stations that cover the Italian territory constitute the INGV strong-motion network. The first channel chosen by the INGV to disseminate the recorded waveforms was through the European Integrated Data Archive (EIDA;http://eida.rm.ingv.it/;http://www.orfeus -eu.org/eida/eida.html), a web portal devoted to seismic data exchange that was developed in the framework of the Network of Research Infrastructures for European Seismology (NERIES) European project (www.neries-eu.org, Networking Activity 3 [NA3]). Since 2008, the INGV raw signals have been downloadable in the Standard for the Exchange of Earthquake Data (SEED) format from the continuous data archive of the INGV National Earthquake Centre (Centro Nazionale Terremoti, CNT). However, the EIDA web portal is devoted in particular to expert end users, and it provides raw data without further information about the waveform metadata and recording sites, which is fundamental for engineering purposes. The recorded RAN strong-motion data from 1972 to 2007 have been available to the scientific community only through specific data requests to the DPC. This changed in 2007, when the RAN data were also disseminated online through the ITalian ACcelerometric Archive (ITACA; Pacor et al., 2011), a static databank that arose in the framework of the S6 Seismological Project (Luzi et al., 2008), with the aim of periodically (usually every 1 year) distributing highquality corrected (i.e., manually processed by expert operators) data to the scientific community. Now, in the last release of ITACA version 2.0 (http://itaca.mi.ingv.it), users can find the RAN strong-motion corrected data up to the end of 2013. Even if the periodic publication of an updated version of ITACA provides new data for the scientific community, within the time span of two subsequent versions, significant earthquakes generally shake the Italian territory. Increasing demands for strong-motion data come from the scientific community soon after an important earthquake, in particular, and the INGV needed to homogeneously organize and disseminate the strongmotion data recorded by its own stations through a new dedicated channel. This motivated the co-operation of several INGV Working Groups to design and develop INGV Strong-Motion Data (ISMD), the first Italian real-time strong-motion web portal. The main scope of the ISMD is real-time archiving, processing, and distribution of strong-motion data recorded by the INGV and partner networks, complete with all of the necessary side information to correctly use the published data. In particular, the automatic system on which the new web portal is based can do the following: 1. check the quality of the raw accelerograms recorded by the INGV strong-motion network; 2. archive and process the data in real time to provide rapid estimations of the main strong-motion parameters of an earthquake; 3. disseminate high-quality strong-motion waveforms and related metadata in real time; 4. collect and distribute all of the available information about the recording sites (i.e., geological, morphological, geophysical); 5. check, update, and homogenize the information related to the INGV strong-motion stations currently installed throughout the entire Italian territory (e.g., coordinates, instrumentation); and 6. within minutes after an earthquake occurs, publish on the website (http://ismd.mi.ingv.it/) a real-time report of the event (e.g., event and waveform metadata, seismic response of recording sites, comparisons between observed and predicted data), jointly providing the binary–Seismic Analysis Code (SAC) uncorrected data (i.e., the raw SEED signals, converted into a new data format), the American Standard Code for Information Interchange (ASCII) corrected accelerograms (i.e., binary-SAC converted into ASCII format, and then processed), as well as the velocity and displacement time series and the related response spectra. The beta version of the ISMD was published during the May–June 2012 ML 5.9 Emilia (northern Italy) seismic sequence. At present it has archived about 23,500 three- component strong-motion records from∼360 Italian events that occurred from 1 January 2012 to the present update of 15 April 2014 with an ML≥3:0Published863-8774T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa

SCIENZAPERTA: EARTH SCIENCE FOR EVERYONE... FINALLY IN MILAN!

ScienzAperta is an outreach science venue that the Istituto Nazionale di Geofisica e Vulcanologia started in 2011 as the spring of science: the doors of the headquarters of science were finally opened to public. A number of events, conferences, seminars, guided tours through the Institute and its laboratories are every year offered to general public. The venue is held in most of the cities where the Institute is located, priority to high seismic and/or volcanic risk regions. On May 2014 we held ScienzAperta for the first time in Milano and open up the doors to schools specifically dealing mostly with seismic hazard in a region where general public not necessarily think it might We offered students conferences, seminars and educational activities to highlight the fun of science and jet raise awareness on proper behaviours in case of earthquake shaking. We asked students and teachers, from elementary to high schools, to fill in a questionnaire that we use to evaluate the appreciation the venue had. One hundred years after Giuseppe Mercalli’s death we could not forget to celebrate his science the city where he was born.UnpublishedMilano3T. Pericolosità sismica e contributo alla definizione del rischiorestricte

A microseismic study in a low seismicity area of Italy: the Città di Castello 2000-2001 experiment

Recent seismological studies contribute to better understand the first order characteristics of earthquake occurrence in Italy, identifying the potential sites for moderate to large size earthquakes. Ad hoc passive seismic experiments performed in these areas provide information to focus on the location and geometry of the active faults more closely. This information is relevant for assessing seismic hazard and for accurately constraining possible ground shaking scenarios. The area around the Città di Castello Basin, in the Northern Apennines (Central Italy), is characterized by the absence of instrumental seismicity (M > 2.5), it is adjacent to faults ruptured by recent and historical earthquakes. To better understand the tectonics of the area, we installed a dense network of seismic stations equipped with broadband and short period seismometers collecting data continuously for 8 months (October 2000-May 2001). The processing of ~ 900 Gbyte of data revealed a consistent background seismicity consisting of very low magnitude earthquakes (ML < 3.2). Preliminary locations of about 2200 local earthquakes show that the area can be divided into two regions with different seismic behaviour: an area to the NW, in between Sansepolcro and Città di Castello, where seismicity is not present. An area toward the SE, in between Città di Castello, Umbertide and Gubbio, where we detected a high microseismicity activity. These findings suggest a probable different mechanical behaviour of the two regions. In the latter area, the seismicity is confined between 0 and 8 km of depth revealing a rather well defined east-dipping, low angle fault 35 km wide that cuts through the entire upper crust down to 12-15 km depth. Beside an apparent structural complexity, fault plane solutions of background seismicity reveal a homogeneous pattern of deformation with a clear NE-SW extension

The Site Characterization Scheme of the INGV Strong Motion Database (ISMD): Overview and Site Classification

This paper describes and discusses the new site characterization scheme adopted for version 2.0 of the INGV (Italian National Institute for Geophysics and Volcanology) Strong Motion Database (ISMD), published on-line in August 2016. To date, the web portal includes more than 145,000 three-component accelerometric waveforms that have been generated by more than 1,200 Italian earthquakes with local magnitude (ML) ≥3.0 and 213 strong-motion stations. Besides the real time distribution of accelerometric data and metadata recorded by INGV and regional partners strong motion networks, one of the main goals of ISMD is to provide a detailed characterization of recording sites from the geological, geomorphological, and geophysical points of view. ISMD allows the correct use of these strong-motion data for a large variety of applications in engineering seismology and earthquake engineering and it allows assessing the soil and topographic categories, as indicated in the current Italian and European seismic codes. To date ISMD represents the first repository for a homogeneous site characterization and classification for the INGV strong-motion stations, intended to be updated in relation to new available data and institutional projects.Published86-986T. Studi di pericolosità sismica e da maremoto4IT. Banche datiJCR Journa

Concessione di stoccaggio di gas naturale “Minerbio stoccaggio” (BO) Struttura Preposta al Monitoraggio Relazione Finale

Comune di Minerbio (BO)Published3SR TERREMOTI - Attività dei Centr

Regional coda Q variations in the western Alps (northern Italy)

To study the microseismicity of the central segment of the western Alps, a local temporal seismic network of six stations was installed in addition to the regional centralized network operating in the area. In 3 months about 220 shocks, with magnitude ranging between 1.0 and 3.8, have been analyzed and located. The epicenter distribution shows a possible subdivision into seismogenetic bands. This subdivision is also recognizable from the spectral characteristics of the analyzed seismic signals. A study of the wave attenuation, in a restricted area well covered by the local network, was carried out through a \u2018coda\u2019 analysis. The results show strong spatial Qc variations, in agreement with the strong lateral heterogeneities that characterize this area. In particular, the Brian\ue7onnais domain, the crystalline massifs and the inner part of the Alpine arc appear to behave as decreasing attenuation bands