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Following the Mw 6.0 Amatrice earthquake on 24 August 2016 in central Italy, the Emersito task force of the Istituto Nazionale di Geofisica e Vulcanologia installed a temporary seismic network focusing on the investigation of amplification effects at municipalities located on topographic reliefs. Fourteen stations were installed at three sites: Amandola, Civitella del Tronto, and Montereale. During the operational period, stations recorded about 150 earthquakes with Mw up to 4.7. Recorded signals were analyzed calculating the horizontal-to-vertical spectral ratios at single station, using both ambient noise and earthquake waveforms, as well as standard spectral ratios (SSRs) to a reference site. To robustly estimate site amplification at each station of the site amplification effect at each station, the influence of backazimuth and epicentral distance is investigated. With the aim of reproducing the observed amplification pattern, 2D numerical simulations were performed on a section orthogonal to the topography major axis, constrained through in situ geological investigations and geophysical surveys. Although at Montereale site no clear amplification effects were observed, at Amandola site, all stations on the relief consistently detected significant peaks at about 4 Hz and along N120–150 azimuth. At Civitella del Tronto, a proper reference station is missing, implying a misleading of site response evaluation in terms of SSRs. Moreover, even if all stations show amplification in the frequency band 1–3 Hz, the direction of the maximum amplification varies from northeast to northwest. At the three sites, observations were successfully reproduced by 2D numerical models, the latter suggesting that topography alone cannot reproduce data, and the interplay with subsoil velocity structure is needed to produce a clear amplification effect. We conclude that according to the previous articles, rather than the sole topography convex shape, the geophysical structure has often a predominant role in controlling the observed amplification pattern on topography.

Objective: To evaluate the outcomes of high-risk (HR) HPV-positive and -negative women affected by high-grade cervical dysplasia. Methods: This is a retrospective multi-institutional study. Medical records of consecutive patients with high-grade cervical dysplasia undergoing conization between 2010 and 2014 were retrieved. All patients included had at least 5 years of follow-up. A propensity-score matching was adopted in order to reduce the presence of confounding factors between groups. Kaplan-Meir and Cox hazard models were used to estimate 5-year outcomes. Results: Overall, data of 2966 women, affected by high-grade cervical dysplasia were reviewed. The study population included 1478 (85%) and 260 (15%) women affected by HR-HPV-positive and HR-HPV-negative high-grade cervical dysplasia. The prevalence of CIN2 and CIN3 among the HR-HPV-positive and -negative cohort was similar (p = 0.315). Patients with HR-HPV-positive high-grade cervical dysplasia were at higher risk of 5-year recurrence (after primary conization) that HR-HPV-negative patients (p < 0.001, log-rank test). Via multivariate analysis, HR-HPV-negative women were at low risk of recurrence (HR: 1.69 (95%CI: 1.05, 4.80); p = 0.018, Cox Hazard model). A propensity-score matched comparison was carried out in order to reduce biases that are related to the retrospective study design. In comparison to HR-HPV-negative patients, thosewith HR-HPV-positive CIN3 was associate with a 8-fold increase in the risk of recurrence (p < 0.001, log-rank test). Conclusions: HR-HPV-negative high-grade cervical dysplasia is not uncommon, accounting for 15% of our study population. Those patients experience more favorable outcomes than patients with documented HR-HPV infection(s). Further prospective studies are needed to corroborate our data.

Previous studies on breast and ovarian carcinoma (BC and OC) revealed constitutional BRCA1 and RAD51C promoter hypermethylation as epigenetic alterations leading to tumor predisposition. Nevertheless, the impact of epimutations at these genes is still debated. One hundred and eight women affected by BC, OC, or both and considered at very high risk of carrying BRCA1 germline mutations were studied. All samples were negative for pathogenic variants or variants of uncertain significance at BRCA testing. Quantitative BRCA1 and RAD51C promoter methylation analyses were performed by Epityper mass spectrometry on peripheral blood samples and results were compared with those in controls. All the 108 analyzed cases showed methylation levels at the BRCA1/RAD51C promoter comparable with controls. Mean methylation levels (&plusmn, stdev) at the BRCA1 promoter were 4.3% (&plusmn, 1.4%) and 4.4% (&plusmn, 1.4%) in controls and patients, respectively (p &gt, 0.05, t-test), mean methylation levels (&plusmn, stdev) at the RAD51C promoter were 4.3% (&plusmn, 0.9%) and 3.7% (&plusmn, 0.9%) in controls and patients, respectively (p &gt, t-test). Based on these observations, the analysis of constitutional methylation at promoters of these genes does not seem to substantially improve the definition of cancer risks in patients. These data support the idea that epimutations represent a very rare event in high-risk BC/OC populations.

In August 2016, a magnitude 6.0 earthquake struck Central Italy, starting a devastating seismic sequence, aggravated by other two events of magnitude 5.9 and 6.5, respectively. After the first mainshock, four Italian institutions installed a dense temporary network of 50 seismic stations in an area of 260 km2. The network was registered in the International Federation of Digital Seismograph Networks with the code 3A and quoted with a Digital Object Identifier (10.13127/SD/ku7Xm12Yy9). Raw data were converted into the standard binary miniSEED format, and organized in a structured archive. Then, data quality and completeness were checked, and all the relevant information was used for creating the metadata volumes. Finally, the 99 Gb of continuous seismic data and metadata were uploaded into the INGV node of the European Integrated Data Archive repository. Their use was regulated by a Memorandum of Understanding between the institutions. After an embargo period, the data are now available for many different seismological studies., Measurement(s)seismic activity • signal conversion functionTechnology Type(s)Sensor • Digitizer DeviceFactor Type(s)locationSample Characteristic - LocationItaly Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.9693602

SUMMARYWe infer seismic azimuthal anisotropy from ambient-noise-derived Rayleigh waves in the wider Vienna Basin region. Cross-correlations of the ambient seismic field are computed for 1953 station pairs and periods from 5 to 25 s to measure the directional dependence of interstation Rayleigh-wave group velocities. We perform the analysis for each period on the whole data set, as well as in overlapping 2°-cells to regionalize the measurements, to study expected effects from isotropic structure, and isotropic–anisotropic trade-offs. To extract azimuthal anisotropy that relates to the anisotropic structure of the Earth, we analyse the group velocity residuals after isotropic inversion. The periods discussed in this study (5–20 s) are sensitive to crustal structure, and they allow us to gain insight into two distinct mechanisms that result in fast orientations. At shallow crustal depths, fast orientations in the Eastern Alps are S/N to SSW/NNE, roughly normal to the Alps. This effect is most likely due to the formation of cracks aligned with the present-day stress-field. At greater depths, fast orientations rotate towards NE, almost parallel to the major fault systems that accommodated the lateral extrusion of blocks in the Miocene. This is coherent with the alignment of crystal grains during crustal deformation occurring along the fault systems and the lateral extrusion of the central part of the Eastern Alps.

In this report, we present the geophysical measurements and the results obtained in the framework of the 2018 agreement between INGV and DPC, called Allegato B2: Obiettivo 1 - TASK B: Caratterizzazione siti accelerometrici (Coord. G. Cultrera, F. Pacor). In this report, the results for station IT.ASP, belonging to the Italian Strong Motion Network (RAN-DPC), are presented. Geophysical measurements consist in a 2D array in passive configuration that provide results in terms of dispersion curves of surface waves. These curves are inverted to obtain a shear-wave velocity (Vs) profile that is suitable for assigning the soil class according to the current Italian seismic code (NTC 2018) and the current Eurocode (EC8).

In this report, we present the geophysical measurements and the results obtained in the framework of the 2018 agreement between INGV and DPC, called Allegato B2: Obiettivo 1 - TASK B: Caratterizzazione siti accelerometrici (Coord. G. Cultrera, F. Pacor). In this report, the results for station IT.PTV, belonging to the Italian Strong Motion Network (RAN-DPC), are presented. Geophysical measurements consist in a 2D array in passive configuration that provide results in terms of dispersion curves of surface waves. These curves are inverted to obtain a shear-wave velocity (Vs) profile that is suitable for assigning the soil class according to the current Italian seismic code (NTC 2018) and the current Eurocode (EC8).

In this report, we present the geophysical measurements and the results obtained in the framework of the 2017 agreement between INGV and DPC, named Allegato B2: Obiettivo 1 - TASK B: Caratterizzazione siti accelerometrici for the characterization of sites of the Italian National Seismic Network (RSN-INGV) with accelerometers and of the Italian Accelerometric Network (RAN-DPC). Here the results for station IV-OPPE are presented. Geophysical measurements are 2D microtremor arrays that provide results in terms of dispersion curves, inverted to obtain shear-wave velocity (Vs) profiles for the studied area, suitable for assigning the EC8 class.

In this report, we present the geophysical measurements and the results obtained in the framework of the 2017 agreement between INGV and DPC, named Allegato B2: Obiettivo 1 - TASK B: Caratterizzazione siti accelerometrici for the characterization of sites of the Italian National Seismic Network (RSN-INGV) with accelerometers and of the Italian Accelerometric Network (RAN-DPC). Here the results for station IV-EUCT are presented. Geophysical measurements are 2D microtremor arrays that provide results in terms of dispersion curves, inverted to obtain shear-wave velocity (Vs) profiles for the studied area, suitable for assigning the EC8 class.

This study presents new geological and seismological data that are used to assess the seismic hazard of a sector of the Po Plain (northern Italy), a large alluvial basin hit by two strong earthquakes on May 20 (M-W 6.1) and May 29 (M-W 6.0), 2012. The proposed interpretation is based on high-quality relocation of 5369 earthquakes ('Emilia sequence') and a dense grid of seismic profiles and exploration wells. The analyzed seismicity was recorded by 44 seismic stations, and initially used to calibrate new one-dimensional and three-dimensional local Vp and Vs velocity models for the area. Considering these new models, the initial sparse hypocenters were then relocated in absolute mode and adjusted using the double-difference relative location algorithm. These data define a seismicity that is elongated in the W-NW to E-SE directions. The aftershocks of the May 20 mainshock appear to be distributed on a rupture surface that dips similar to 45 degrees SSW, and the surface projection indicates an area similar to 10 km wide and 23 km long. The aftershocks of the May 29 mainshock followed a steep rupture surface that is well constrained within the investigated volume, whereby the surface projection of the blind source indicates an area similar to 6 km wide and 33 km long. Multichannel seismic profiles highlight the presence of relevant lateral variations in the structural style of the Ferrara folds that developed during the Pliocene and Pleistocene. There is also evidence of a Mesozoic extensional fault system in the Ferrara arc, with faults that in places have been seismically reactivated. These geological and seismological observations suggest that the 2012 Emilia earthquakes were related to ruptures along blind fault surfaces that are not part of the Pliocene-Pleistocene structural system, but are instead related to a deeper system that is itself closely related to re-activation of a Mesozoic extensional fault system. (C) 2015 Elsevier B.V. All rights reserved.

The Montello anticline is a morphotectonic feature of the east pede-mountain of the South Alpine Chain in northern Italy, which lies ca. 40 km northwest of Venice, Italy. The purpose of this study is to characterize the present-day crustal deformation and seismotectonics of the Montello area through multi-parametric geophysical observations. We used new data obtained from the installation of a temporary network of 12 seismic stations and 6 GPS sites. The GPS observations indicate that there is ~ 1 mm/yr shortening across the Montello thrust. Sites located north of the Montello thrust front deviate from the ~ NNW-ward Adria–Eurasia convergence direction, as they are constrained by a relative rotation pole in northwestern Italy that has a NNE-ward motion trend. Over 18 months, seismographic recordings allowed us to locate 142 local seismic events with Ml 0.5–3.5 with good reliability (rms 0.80. The source focal solutions indicate that: (i) there is thrusting seismic activity on the basal, sub-horizontal, portion of the Montello structure; and (ii) strike-slip source kinematics prevail on the western edge of the Montello hill. Our observations on the source mechanisms and the measured crustal deformation confirm that the Montello thrust is tectonically active.

In this paper we present a feasibility study for the surface seismic monitoring of the “Sant’Alberto” gas reservoir (Po Plain, Northern Italy). The project was commissioned to INGV in the framework of the activities planned by the oil & gas EP 2) the installation of the borehole station allows to improve the detection threshold everywhere within DI, and up to ML =-0.4 nearby the reservoir; and 3) localization thresholds obtained in the crustal volume included in DE, but not in DI, show values around ML = 1.0.

In the framework of the S2 DPC-INGV 2014–2015 project ( https://sites.google.com/site/ingvdpc2014progettos2/ ), several field surveys were designed with the aim to investigate the local seismic site response of selected Italian Accelerometric Network strong motion stations. In this study the results obtained at Sorbolo, Lesignano de’ Bagni, and Castelfranco Veneto, three sites located in the Po alluvial basin (northern Italy), were presented. In particular, at each site, ambient vibration surveys were performed both in single stations and two dimensional arrays configurations. The ambient vibration arrays were analyzed to obtain at each site the shear-wave velocity (Vs) profile, until depths in correspondence of which the Vs show values higher than 800 m/s (i.e. lower bound for the soil category A, as now defined in the Italian seismic code for building). In this way, data were processed through a joint inversion computed using both the Rayleigh waves dispersion curve and the ellipticity curve deduced from the horizontal-to-vertical spectral ratios calculated from the microtremor single station measurements. In general, the obtained profiles show an increasing depth of the main Vs discontinuity (i.e. the seismic bedrock) from 60 to 320 m, moving from the edge to the central part of the Po alluvial basin. To support the outcomes of the field experiments, the available earthquakes recorded at each station in the last decades were processed in terms of the horizontal-to-vertical spectral ratios. Although in many cases the resonance frequencies are comparable with those obtained from microtremor, a high variability is observable depending on the selected portions of each single earthquake. Finally, residual analysis were carried out comparing the recorded ground motion to predicted data as provided by the actual Italian ground motion prediction equations, calibrated both at national and at regional scale.

This study deals with the impact of deep‐soil discontinuities on ground‐motion amplification in the Po alluvial basin (northern Italy), and consequently, on long‐period probabilistic seismic‐hazard analysis estimates. The focus is on Castelleone, where a seismic station of the Italian National Seismic Network has been deployed since 2009. To define a detailed shear‐wave velocity ( V S ) profile, extensive active and passive geophysical surveys were carried out. The active measurements included seismic profiles examined through standard refraction techniques and multichannel analysis of surface waves. The passive methods included ambient vibration measurements in both single and array configurations. In particular, three microtremor arrays with increasing apertures were performed to capture the experimental dispersion curve down to 0.2 Hz. The horizontal‐to‐vertical spectral ratio (HVSR) showed two main peaks, at 0.17 and 0.70 Hz. A joint inversion of the experimental phase‐velocity dispersion and HVSR curves was performed to obtain the V S profile. The data show two main discontinuities at ∼160 and 1350 m in depth. According to the Italian and European seismic codes, the shallow V S discontinuity can be ascribed to the seismic bedrock (i.e., V S >800 m/s), whereas the deeper one is observed at the transition between Pliocene–Quaternary deposits and Miocene marls. Preliminary site‐specific seismic‐hazard analysis in terms of displacement response spectra for periods up to 10 s shows that neglecting the effects of the deeper discontinuity implies underestimation in hazard estimates of up to about 49% for mean return period (MRP) of 475 years and about 57% for MRP of 2475 years, with possible consequences regarding the design of very tall buildings and large bridges.

Online Material: Earthquake catalog and strong motion stations. 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; see Data and Resources for a complete listing of all websites listed in this article) was designed and installed by the Agenzia Nazionale per le Nuove Tecnologie, 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). …

On August 24, 2016, at 01:36 UTC a MW 6.0 earthquake struck an extensive area of the Central Apennines (Italy). It was followed by a large aftershock (MW 5.3, August 24, 02:33 UTC) and about 20 earthquakes with magnitude greater than 4.0, located between the towns of Norcia and Amatrice. Due to the mainshock magnitude and the widespread damaging level of buildings in the epicentral area, the Emersito task force has been mobilized by the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The aim of Emersito is to carry out and coordinate the monitoring of local site effects, caused by geological and geomorphological settings. During the first days of the seismic emergency, Emersito installed a temporary seismic network for site effect studies at 4 municipalities close to the epicentral area (Amandola, Civitella del Tronto, Montereale and Capitignano), using 22 stations equipped with both velocimetric and accelerometric sensors. The selection of the sites where stations have been installed was mainly driven by the proximity to the epicentral area (without interfere with the rescue operation) and by peculiar geologic and geomorphologic settings (topographic irregularities, fault zones, alluvial plains).

ISMD is the real time INGV Strong Motion database. During the recent August-September 2016 Amatrice, Mw 6.0, seismic sequence, ISMD represented the main tool for the INGV real time strong motion data sharing. Starting from August 24th, the main task of the web portal was to archive, process and distribute the strong-motion waveforms recorded by the permanent and temporary INGV accelerometric stations, in the case of earthquakes with magnitude ≥ 3.0, occurring in the Amatrice area and surroundings. At present (i.e. September 30th, 2016), ISMD provides more than 21.000 strong motion waveforms freely available to all users. In particular, about 2.200 strong motion waveforms were recorded by the temporary network installed for emergency in the epicentral area by SISMIKO and EMERSITO working groups. Moreover, for each permanent and temporary recording site, the web portal provide a complete description of the necessary information to properly use the strong motion data.

Online Material: Supplemental table, figures. On 20 May 2012, at 02:03:52 GMT, an earthquake with M w 6.1 (Regional Centroid Moment Tensor [RCMT]; http://www.bo.ingv.it/RCMT) occurred in northern Italy striking a densely populated area. The mainshock was followed a few hours later by two severe aftershocks having the same local magnitude ( M L 5.1, Fig. 1a), and by hundreds of smaller aftershocks. Nine days later, on 29 May, at 07:00:03 GMT, a second event with moment magnitude M w 6.0 (RCMT; http://www.bo.ingv.it/RCMT) occurred to the west, on an adjacent fault segment. This event was also followed by hundreds of aftershocks, three of them having local magnitudes 5.3, 5.2, and 5.1 (Fig. 1a; locations from Istituto Nazionale di Geofisica e Vulcanologia, hereinafter INGV; http://iside.rm.ingv.it/; Malagnini et al. , 2012; Scognamiglio et al. , 2012). Despite the moderate number of casualties if compared to other major events in Italian history, the economic loss was extremely high, resulting in about EUR 5 billion (AON Benfield, 2012; http://www.aon.com/), as the majority of Italian industrial activities and infrastructure concentrate in this area, the eastern Po plain, which is the largest sedimentary basin in Italy. Figure 1. (a) Simplified geological sketch of the Po plain and surrounding northern Apennines and Southern Alps fold‐and‐thrust belts. Key to symbols: stars, earthquakes of M >5 of the 2012 Emilia–Romagna seismic sequence, dimension proportional to the magnitude; dark gray areas, Composite Seismogenic Sources (CSS) of the DISS database (http://diss.rm.ingv.it), the upper tip of the fault plane is highlighted in black. Focal mechanisms of the 20 and 29 May 2012 earthquakes are from the TDMT database (http://cnt.rm.ingv.it/tdmt.html). (b) Simplified geological sections crossing the Po plain and showing thickness variation of the Plio‐Quaternary sedimentary sequence correlated with syncline–anticline pairs of the northern Apennines and Southern Alps thrust belts. Modified from Cassano et al. (1986), sections 1, 2, …

DATI ACCELEROMETRICI INGV IN TEMPO QUASI REALE

In their comments Bonini et al. argue that our seismotectonic interpretation of the Emilia 2012 seismic sequence does not agree with observations, and follow three lines of arguments to support their statement. These concern the structural interpretation of seismic reflection profiles, the relationship between seismogenic sources and seismicity patterns, and the fit of inferred fault geometry to InSAR observations. These lines of arguments are mostly repeating what has been previously presented by the same authors, and none of them, as discussed in detail in our reply, presents a strong case against our structural interpretation, that, we are convinced, does not conflict with the available data. The two adjacent rupture surfaces outlined by accurately relocated aftershocks are an indication of the presence of two different active fault planes. Interpretation of seismic profiles supports seismological observation and indicates the occurrence of relevant along-strike changes in structural style. These pieces of information have been integrated to build a new seismotectonic interpretation for the area of the Emilia 2012 seismic sequence. Analysis of geodetic data from the area of the Emilia earthquakes has produced very different models of the fault planes; unlike what has been stated by Bonini et al., who see a difficult fit to InSAR data for the fault planes we have identified, the most recent results are consistent with our interpretation that see a steep fault in the upper 8–10 km under the Mirandola anticline. We point out that the geological structures in the subsurface of the Ferrara Arc do change along strike, and the attempt of Bonini et al. to explain both the May 20 and May 29 sequences using a single cross section is not appropriate.

In this work, the results of a quick microtremor survey performed in the municipalities situated in the epicentre area of the Ml 5.2 2004 Salo earthquake (North Italy) are presented. The aim of this study is to understand if the large amount of damage caused by the event (about 215 million euros only in the areas near to the epicenter) is correlated more to the local surface geology conditions or to the vulnerability of ancient Italian historical centers. A preliminary seismic zonation was carried out in 5 villages including about 30 measurements of microtremors analyzed by the Nakamura technique (hereinafter HVNR). The points of measurement were carefully selected considering sites located both near damaged buildings and over different local geology conditions (alluvium deposits, fluvial-glacial deposits, debris fans and rock). In order to strengthen the HVNR results and to evaluate the reliability of the Nakamura analysis, a comparison with spectral ratios calculated on earthquakes (hereinafter HVSR) re...

[…] Recently, an INGV working group developed the first version of a web portal with the aim of archiving, processing and distributing accelerometric data recorded by permanent and temporary INGV stations. This web portal (www.mi.ingv.it/ISMD/) is composed of two main modules: the former is known as the INGV Strong Motion Data (ISMD, www.mi.ingv.it/ISMD/ismd.html/) and has as its main scope the analyse and distribution in quasi-real time (a few hours after event occurrence) of the uncorrected accelerometric data, and the related metadata obtained after an automatic processing procedure. This latter, known as the Dynamic Archive (DYNA, http://dyna.mi.ingv.it/DYNA-archive/) is a dynamic database where manually post-processed accelerometric waveforms are provided, together with their metadata. Both of these archives are designed and structured in such a way that their compilations and updating will be almost completely automatic. At the end of May 2012, a first prototype of the ISMD module was published, providing the uncorrected strong-motion data recorded by the INGV stations for the main events of the Emilia seismic sequence. […]

On May 20, 2012, at 02:03 UTC, a Ml 5.9 reverse-fault earthquake occurred in the Emilia-Romagna region, northern Italy, at a hypocentral depth of 6.3 km (http://iside.rm.ingv.it/), close to the cities of Modena and Ferrara in the plain of the Po River. The epicenter was near the village of Finale Emilia where macroseismic intensity was assessed at 7 EMS98 [Tertulliani et al. 2012, this issue], while the closest accelerometric station, MRN, located less than 20 km west-ward at Mirandola (Figure 1) recorded peaks of ground accelerations of about 300 cm/s2 (www.protezionecivile.gov.it/resources/cms/documents/Report_DPC_1_Emilia_EQSd.pdf). The mainshock triggered liquefaction phenomena a few kilometers eastwards of the epicenter, around the village of San Carlo. On the same day, two other shocks of Ml 5.1 followed (02:07, 13:18 GMT; http://iside.rm.ingv.it/). On May 29, 2012, at 07:00 UTC another Ml 5.8 earthquake hit the region (http://iside.rm.ingv.it/), with the epicenter close to the village of Mirandola (Figure 1). Three other strong aftershocks occurred afterwards, of Ml 5.3 (May 29, at 10:55), Ml 5.2 (May 29, at 11:00) and Ml 5.1 (June 3, at 19:20). For a detailed description of the seismic sequence, see Moretti et al. [2012], Scognamiglio et al. [2012], and Massa et al. [2012], in this issue. The Emilia seismic sequence resulted in 25 casualties, several of whom were among the workers in the many factories that collapsed during working hours, and there was extensive damage to monuments, public buildings, industrial sites, and private homes. […]

On May 20th 2012, at 02:03:52 UTC, a ML 5.9 (Mw 6.0) earthquake struck northern Italy (http://cnt.rm.ingv.it/). The epicentre was localized at 44.89˚ N and 11.23˚ E, in an area among the cities of Ferrara, Modena and Mantova. The event occurred at a depth of about 6.3 km, and was characterized by a reverse focal mechanism (http://cnt.rm.ingv.it/tdmt.html/). From May 20th, thousand of earthquakes, the strongest of which with a ML 5.8 (May 29th, 07:00:03 UTC), occurred in the same area (http://iside.rm.ingv.it/).This note presents a new web site, www.mi.ingv.it/ISMD/ismd.html/ (Figure 1) that includes about 2000 three-component strong-motion recordings of the events with 4.0 ≤ ML ≤ 5.9 occurred in the central part of the Pianura Padana Emiliana (northern Italy) from May 20th to June 12th. The data come from all INGV strong-motion stations installed in northern Italy (i.e. strong-motion stations of the National Seismic Network, RSN [Amato and Mele 2008]; Strong-Motion Network of Northern Italy, RAIS, http://rais.mi.ingv.it/ [Augliera et al. 2011]) and selected with a minimum latitude of 43.5˚ N. The earthquake locations reported in the web site come from the National Earthquake Centre of INGV (http://cnt.rm.ingv.it/).

One of the most important issue in seismic hazard and microzonation studies is the evaluation of local site response (i.e. the tendency of a site to experience during an earthquake greater or lower levels of ground shacking with respect to another). In general site effects reflect all modifications (in amplitude, frequency content and duration) of a wave-field produced by a seismic source during the propagation near the surface, due to particular geologic (stratigraphy and morphology), geotechnical (mechanical properties of deposits) and physical (e.g. coupling of incident, diffracted and reflected seismic waves) conditions of a particular site. Actually local seismic amplification represents one of the main factors responsible for building damage during earthquakes: this statement is supported by well documented evidences of structural damages during past moderate to high energy events occurred both in Italy (e.g. 23th November 1980, Mw 6.9, Irpinia earthquake, Faccioli, 1986; 26th September 1997, Mw 6.0, Umbria-Marche earthquake, Caserta et al., 2000; the 31th October 2002, Mw 5.7, Molise earthquake, Strollo et al., 2007; 6th April 2009, Mw 6.3, L’Aquila earthquake, Cultrera et al., 2009) and in other worldwide countries (e.g. 3rd March 1985, Mw 7.8, Chile earthquake, Celebi, 1987; 17th August 1999, Mw 7.6, Izmit earthquake, Sadik Bakir et al., 2002). For this reason the site effects evaluation, performed by experimental methods but also through numerical simulations, has attracted the attention of engineering seismology and earthquake engineering communities. Of consequence, in the last decade many experiments were performed in correspondence of different setting such as alluvial basins (Parolai et al., 2001 and 2004; Ferretti et al., 2007; Massa et al., 2009; Bindi et al., 2009) or topographies (e.g. Pischiutta et al., 2010; Massa et al., 2010; Buech et al., 2010; Marzorati et al., 2011; Lovati et al., 2011). The present work has the aim to evaluate the capabilities of the most common passive methods at present used in seismology to evaluate the site response: HVSR (Horizontal to Vertical Spectral Ratio technique on seismic noise, Nakamura, 1989, or earthquakes, Lermo & Chavez Garcia, 1993) and SSR (Standard Spectral Ratio, Borcherdt, 1970). The reliability of

A temporary network of 33 seismic stations was deployed in the area struck by the 6th April 2009, Mw 6.1 (Scognamiglio et al. in Seism Res Lett 6/81, 2010), L’Aquila earthquake (central Italy), with the aim to investigate the site amplification within the Aterno river Valley. The seismograms of 18 earthquakes recorded by 14 of the 33 stations were used to evaluate the average horizontal to vertical spectral ratio (HVSR) for each site and the standard horizontal spectral ratio (SSR) between a site and a reference station. The obtained results have been compared to the geological and geophysical information in order to explain the resonance frequencies and the amplification levels with respect to surface geology of the valley. The results indicate that there is no uniform pattern of amplification, because of the complex geologic setting, as the thickness and degree of cementation of the deposits is highly variable.

In the present work the seismic site response of Narni ridge (Central Italy) is evaluated by comparing experimental results and numerical simulations. The inhabited village of Narni is located in central Apennines at the top of a steep massive limestone ridge. From March to September 2009 the site was instrumented with 10 weak-motion stations, 3 of which located at the base of the ridge and 7 at the top. The velocimetric network recorded 642 events of ML up to 5.3 and hypocentral distance up to about 100 km. The great amount of data are related to the April 2009 L’Aquila sequence. The site response was analyzed using both reference (standard spectral ratio, SSR) and non reference spectral techniques (horizontal to vertical spectral ratio, HVSR). Moreover directional analyses were performed in order to evaluate the influence of the ridge orientation with respect to the selected source-site paths. In general the experimental results show amplification factors for frequencies between 4 and 5 Hz for almost all stations installed along the crest. The SSR technique provides amplification factors up to 4.5 in a direction perpendicular to the main elongation of the ridge. The results obtained from the data analyses were used as a target for bidimensional and tridimensional numerical simulations, performed using a hybrid finite-boundary element method and a boundary element method for 2D and 3D modelling, respectively. In general, the results obtained through numerical simulation fit well the experimental data in terms of range of amplified frequencies, but they underestimate by a factor of about 2 the observed amplifications.

From March to September 2009, a velocimetric network was installed in Narni, central Italy, a village on the top of a limestone ridge. The aim was to investigate local site effects due to the 220-m-high ridge, which is characterized by slopes ranging from 22° to 35°. To investigate amplification without and with a reference site, three stations were installed at the base of the hill and seven at the crest. The network recorded 702 earthquakes, many of them from the 2009 L’Aquila sequence. To determine the dependence of amplification on the morphological features, the spectra were computed for horizontal components rotated into a range of azimuths. Both the ratio of the horizontal-to-vertical-component spectra and the ratio of the spectra at the ridge crest with respect to a reference station at the base of the ridge showed amplification by a factor of circa 4.5 for frequencies between 4 Hz and 5 Hz. The highest amplifications were seen for the directions of the ground motion perpendicular to the main elongation of the ridge. Finally, considering events with an epicentral distance less than 30 km, empirical ground-motion models were calibrated for maximum horizontal peak ground acceleration (PGA), velocity, and acceleration response spectra (5% damping) up to 1 s, to estimate the site-corrective coefficients for topographic amplification. The data show corrective coefficients between 0.35 and 0.48 (log 10 scale; amplification, 2.2–3.0) for the spectral ordinates between 0.2 s and 0.3 s.

Geological, geophysical and geotechnical investigations, for the characterization of the strong-motion recording sites managed by the Italian Civil Protection, have been carried out in the framework of the project “Italian strong-motion database in the period 1972–2004”. The project aimed at creating an updated database of strong-motion data acquired in Italy by different institutions in the time span 1972–2004, and at improving the quality of disseminated data. This article illustrates the state of the recording site characterization before the beginning of the project, explains the criteria adopted to select the sites where geophysical/geotechnical investigation have been performed and describes the results of the promoted field surveys.