GNGTS 2018 - 37° Convegno Nazionale

356 GNGTS 2018 S essione 2.1 ENGINEERING STRONG-MOTION (ESM) FLATFILE: A TOOL TO TEST AND CALIBRATE GROUND MOTION MODELS IN EUROPE AND MIDDLE-EAST G. Lanzano 1 , INGV-MI team 1 : L. Luzi, G. Lanzano, R. Puglia, F. Pacor, E. Russo, S. Sgobba, C. Felicetta, M. D’Amico 1 , GFZ-Potsdam team 2 : F. Cotton, D. Bindi, G. Weaterhill, S. Reddy Kotha 1 Istituto Nazionale di Geofisica e Vulcanologia, Milano, Italy 2 GeoForschungs Zentrum, Potsdam, Germany  Introduction. The Engineering Strong-Motion (ESM) flatfile is a parametric table which contains metadata and intensity measures of manually processed waveforms included in the ESM database (http://esm.mi.ingv.it ; Luzi et al., 2016). The flatfile has been developed within the European Project EPOS (European Plate Observing System Implementation Phase; http:// epos-ip.org/ ) and it is disseminated throughout a web portal (http://esm.mi.ingv.it/flatfile-2018/ flatfile.php) for research and technical purposes. The ESM strong motion flatfile is the result of a collaboration between EPOS Task 8.6.3 European Ground Motion Prediction Equations (GMPEs) Database (Lead GFZ) & Task 8.4.2 Strong Motion Data and Products Services (Lead INGV). The flatfile has been released in March 2018 and is composed by 23,014 recordings from 2179 earthquakes and 2080 stations. The waveforms in the flatfile are uniformly processed by using the processing service of the Engineering Strong Motion Database (ESM, http:// esm.mi.ingv.it/processing/, Puglia et al., 2018). The events are characterized by magnitudes in the range 3.5–8.0 and refer to different tectonic regimes, such as shallow active crustal and subduction zones. A significant effort in the compilation of the flatfile has been spent on metadata revision in order to keep it traceable including specific fields for the references of each metadata (i.e. event, source and station). ESM flatfile updates the previous European datasets, such as ISESD (Internet-Site for European strong motion Data, Ambraseys et al., 2004) and RESORCE (Reference Database for Seismic Ground Motion in Europe; Akkar et al., 2014). The fields of flatfile can be grouped as 6 main blocks (Lanzano et al., 2018): i) Event-related metadata; ii) Source-related metadata; iii) Station-related metadata; iv) Metrics of source-to-site distances; v) Waveform-related metadata; vi) Intensity Measures (IMs) for each component (2 horizontal and 1 vertical) and with respect to horizontal RotD50 , RotD0 and RotD100 , proposed by Boore (2010). The flatfile is distributed as a ‘.csv’ file, provided in three files: • ESM_flatfile_SA.csv table with 36 spectral acceleration ordinates (5% damping) in the period range 0.01–10 s; • ESM_flatfile_SD.csv table with 36 spectral displacements ordinates (5% damping) in the period range 0.01–10 s; • ESM_flatfile_FAS.csv table with 103 acceleration Fourier amplitudes smoothed (b=40) using the Konno and Ohmachi (1998) algorithm in the frequency range 0.04–50 Hz. Intensity measures also include peak and integral parameters and duration of each waveform. Statistics. Fig. 1a shows the number of recordings and events in the flatfile as a function of time for two distance ranges (i.e. epicentral distances less than 50 and 10 km). The amount of data is nearly constant until 1996 and whereas it significantly increases as a consequence of the rapid growth of the number of strong motion stations. Peaks in the number of recordings are observed when important seismic sequences occurred. The magnitude-distance distribution is given in Figure 1b, grouped by style of faulting (SoF). The moment magnitude is available for 68% of the data. Local magnitude M L is used when M w is not provided; in the few cases of missing both M w and M L , the surface magnitude M s is considered. In the following, we will refer to a generic “Magnitude” or “M” which corresponds to the mixed magnitude obtained according to the above described procedure. In Fig. 1b, the distance is Joyner-Boore, R JB , if available, otherwise the epicentral distance, R EPI . Data are well sampled in the magnitude range 3.5–6.5 and for distance up to 300 km. There is also a significant number of records related to strong events with magnitude in the range 6.0 - 7.8, corresponding to 6% of the records.