Felicetta, Chiara

The region of central Italy is well known for its moderate-to-large earthquakes. Events such as 2016 Mw 6.2 Amatrice, generated in the shallow extensional tectonic regime, motivate numerical simulations to gain insights into source-related ground-motion complexities. We utilize a hybrid integral–composite kinematic rupture model by Gallovič and Brokešová (2007) to predict ground motions for other hypothetical Amatrice fault rupture scenarios (scenario events). The synthetic seismograms are computed in 1D crustal velocity models, including region-specific 1D profiles for selected stations up to 10 Hz. We create more than ten thousand rupture scenarios by varying source parameters. The resulting distributions of synthetic spectral accelerations at periods 0.2–2 s agree with the empirical nonergodic ground-motion model ofSgobbaetal.(2021)forcentral Italy in terms of the mean and total variability. However, statistical mixed-effect analysis of the residuals indicates that the between-eventvariability of the scenarios exceeds theempirical one significantly. We quan tify the role ofsourcemodelparametersinthemodelinganddemonstratethepivotalroleof theso-called stress parameterthatcontrols high-frequencyradiation. Weproposerestricting thescenariovariability tokeepthebetween-eventvariabilitywithintheempiricalvalue.The presented validation of the scenario variability can be generally utilized in scenario model ing for more realistic physics-based seismic hazard assessment.

The behaviour of the ground surface and of structures subjected to earthquakes can be estimated analysing the accelerograms of seismic records. The ground motion is strongly dependent on several factors and the ability to record, characterize and extract the main features of waveforms is essential to better understand these dependencies. One of the most difficult steps of this analysis is the waveforms’ processing. Its purpose is the estimation and the removal of noise in the records, to evaluate reliable ground motion. In this framework a processing tool fully integrated within the Engineering Strong Motion (ESM) database was designed [Paolucci et al., 2011; Luzi et al., 2016]. In the last decade the number of waveforms is sharply increased and so is the time it takes to process them. To solve this issue a possible solution is to broaden the number of qualified people involved in the processing. The main aim of this tutorial is to teach the largest number of people how to use the ESM processing tool and to provide some important guidelines for the thresholds of the parameters to set. In the text a step by step processing routine is depicted with a description of the purpose for each parameter. In addition, a suite of explanatory examples with peculiar situations is given.

This work aims at identifying and modelling statistical dependencies between empirical amplification functions of sites in central Italy and the main geological and geophysical characteristics of the region, within a geostatistical analysis framework. The empirical functions, named δS2S, are estimated by decomposing the re siduals of the median predictions of a non-ergodic ground motion model of elastic acceleration response spectra developed for the reference region. To select the model that best describes the spatial variability of the data, the performance of stationary and non-stationary spatial models is compared, the latter being able to constrain the prediction of the empirical functions to physical quantities available in the region and descriptive of the geology, topography and geographical location of the site. Finally, we obtain optimal models of δS2S, for each spectral ordinate, parameterised as a function of geographical coordinates and an input map of shear wave velocity in the upper 30 m (Vs30) constructed ad hoc by combining information gathered from two high-resolution maps available for the region. The methodology allows the development of a new practice-oriented framework for the empirical estimation of site amplification, which can be adopted for the gen eration of shaking scenarios in the context of regional hazard and seismic risk assessment.

The Campo Felice basin, in the central Apennines seismic belt (Italy), developed in the hangingwall of a 30 km-long system of NW-trending normal faults with Holocene paleoseismic activity and potential sources of M 6–7 earthquakes. We provide the first subsurface images of a key portion of the basin bounded by the Mt. Cefalone fault along two intersecting profiles trending NNE-SSW (CF-Dip, 1195 m-long) and WNW-ESE (CF-Strike, 1315-m long). We combined high-resolution depth-migrated reflection sections with P-wave velocity and electrical resistivity tomography models. CF-Dip profile displays a wedge-like syn-tectonic sedimentary sequence of alluvial and glacial deposits with Vp ∼ 2500–3000 m/s and resistivity > 500 Ωm in the hangingwall of Mt. Cefalone fault, overlying a high-Vp (>4000 m/s) limestone bedrock ∼ 300 m deep. The whole sequence displays reflectors truncated by the Mt. Cefalone fault zone and subsidiary antithetic faults. CF-Strike profile, tied to three 80–110 m-deep boreholes, shows a thick fluvio-lacustrine sequence with low-Vp (<2000 m/s) and low resistivity (<100 Ωm), and a bedrock that deepens to the southeast (>450 m). Single-station ambient noise measurements display Horizontal to Vertical Spectral Ratios with peaks at ∼1 Hz, decreasing to ∼0.8 Hz to the southeast in agreement with the bedrock deepening indicated by seismic profiling. According to our results, the Campo Felice basin is a deep asymmetric half-graben controlled by faulting whose activity likely started before the Middle Pleistocene. Our minimum displacement estimate accrued in the past 0.5 Ma by the Mt. Cefalone fault is in the range of ∼100–250 m.

Il giorno 9 novembre 2022, alle 06:07:24 UTC (07:07:24 ora locale) un terremoto di magnitudo momento (MW) pari a 5.5 ha interessato la Costa Marchigiana Pesarese (Pesaro Urbino). A causa della magnitudo del mainshock e del livello di danneggiamento riscontrato, l’INGV ha attivato il gruppo operativo EMERSITO (http://emersitoweb.rm.ingv.it/index.php/it/), il cui obiettivo è di svolgere e coordinare le campagne di monitoraggio per studi di effetti di sito e di microzonazione sismica. Il gruppo operativo ha provveduto all’installazione di una rete sismica temporanea nel territorio del comune di Ancona; molte delle stazioni sismiche sono state installate in corrispondenza di edifici pubblici (scuole, Tribunale, Marina Militare, strutture religiose), grazie alla collaborazione con la sede INGV di Ancona, con la Protezione Civile Regione Marche, la Marina militare e la Capitaneria di Porto. Nel presente Report vengono brevemente riassunte le attività già svolte (si vedano i Report precedenti), discusse le analisi dei dati raccolti e mostrati alcuni risultati preliminari riguardanti la rete sismica temporanea. Sono state effettuate le seguente analisi preliminari: qualità delle registrazioni; rapporti spettrali su rumore sismico ambientale e su una selezione di terremoti registrati; analisi della dipendenza dei risultati dei rapporti spettrali dalla direzione del moto sismico (polarizzazione del segnale); calcolo dei meccanismi focali su alcuni eventi selezionati. Infine è stato prodotto un modello geologico semplificato, inclusivo delle informazioni derivanti dalle indagini geologiche e geofisiche preesistenti, che fornisce una chiave interpretativa dei risultati ottenuti.

Strong-motion records and open access to strong-motion data repositories are fundamental to seismology, earthquake engineering and practice. The main archive to disseminate high quality processed waveforms for the European-Mediterranean region is the Engineering Strong-Motion Database (ESM, https://esm-db.eu). ESM is developed under the general coordination of the ORFEUS Strong-Motion Management Committee (Observatories and Research facilities for European Seismology; http://orfeus-eu.org/), with the aim to provide users daily access to updated strong-motion waveforms of earthquakes with magnitude greater than 4, mainly recorded in the Pan-European regions. ESM is fully compatible with the European Integrated Data Archive (EIDA; http://orfeus-eu.org/data/eida/) and disseminates waveforms and related metadata according to the Federation of Digital Seismograph Networks (FDSN, https://www.fdsn.org/networks/). The strategy of ESM is to disseminate only manually processed data to ensure the highest quality. However, the rapid increase in the number of waveforms, due to the increment of seismic stations, leads to the need of automatic procedures for data processing and data quality control. In this work, we present ESMpro, a modular Python software for a renewed processing framework of ESM. The ESM data processing is improved with: (1) automated data quality-check that speeds up the processing time through the rejection of poor-quality records; (2) advancement of the automatic settings for waveform trimming and filtering; (3) introduction of different algorithms for data processing (Paolucci et al., 2011; Schiappapietra et al., 2021); (4) modular and flexible software structure that allows the addition of new algorithms and custom workflows. The accuracy of the updated automatic processing is evaluated by comparison with the waveforms processed by expert analysts, used as benchmarks (Mascandola et al., 2022). ESMpro is distributed in a stand-alone Beta version available on GitLab (D’Amico et al., 2022; https://shake.mi.ingv.it/esmpro/), following the Open Science principles to promote collaborations and contributions from the scientific community. In the next future, a renewed ESM web-processing frontend will be developed to include the ESMpro improvements, as well as new functionalities to process stand-alone data (i.e., not stored in the ESM database) and to allow different input seismic data formats. How to cite: Mascandola, C., D'Amico, M., Russo, E., Luzi, L., Lanzano, G., Felicetta, C., Pacor, F., and Sgobba, S.: Toward a renewed data processing of the Engineering Strong Motion (ESM) database, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2210, https://doi.org/10.5194/egusphere-egu23-2210, 2023.