Hazard-consistent response spectra in the Region of Murcia (Southeast Spain): comparison to earthquake-resistant provisions

Hazard-consistent ground-motion characterisations of three representative sites located in the Region of Murcia (southeast Spain) are presented. This is the area where the last three damaging events in Spain occurred and there is a significant amount of data for comparing them with seismic hazard estimates and earthquake-resistant provisions. Results of a probabilistic seismic hazard analysis are used to derive uniform hazard spectra (UHS) for the 475-year return period, on rock and soil conditions. Hazard deaggregation shows that the largest hazard contributions are due to small, local events for short-period target motions and to moderate, more distant events for long-period target motions. For each target motion and site considered, the associated specific response spectra (SRS) are obtained. It is shown that the combination of two SRS, for short- and long-period ground motions respectively, provides a good approximation to the UHS at each site. The UHS are compared to design response spectra contained in current Spanish and European seismic codes for the 475-year return period. For the three sites analysed, only the Eurocode 8 (EC8) type 2 spectrum captures the basic shape of the UHS (and not the EC8 type 1, as could be expected a priori). An alternative response spectrum, anchored at short- and long-period accelerations, is tested, providing a close match to the UHS spectra at the three sites. Results underline the important contribution of the frequent, low-to-moderate earthquakes that characterize the seismicity of this area to seismic hazard (at the 475-year return period)

Task 1 - Deliverable 1: Database structure

The Italian strong motion data base (Italian Strong Motion Data Base) is a joint product of the agreement between the Dipartimento della Protezione Civile – Ufficio Valutazione Prevenzione e Mitigazione del Rischio Sismico ed Attività ed Opere Post-Emergenza (Department of Civil Protection – Evaluation, Prevention and Mitigation of Seismic Risck and Post-Emergency Works) and the Istituto Nazionale di Geofisica e Vulcanologia (National Institute of Geophysics and Volcanology). The data base is handled through two different relational data base management system: Ms Access® 2003, of major use among research institutions and public administrations, for CD-ROM release, and MySQL for the web distribution. The selection of the former product is driven by the simplicity of the software, the worldwide diffusion and the possibility of being linked to software’s for the management of spatial data, such as ESRI ArcGis® and Arcview®, and software for the scientific calculation such as Matlab ®. The data base will store the information regarding the seismic events, the recording stations, the installed instruments, the main features of the recordings and the engineering parameters. The structure is based on a previous version of the Italian strong-motion data base created by ENEA in collaboration with Department of Civil Protection, which stores the information regarding the accelerometric recordings in the time span 1972-1993. This manuscript will explain the structure of the tables containing the information, the data base architecture, the relationships existing among tables and the technical features for data input.Progetto DPC-INGV S6 “Data base dei dati accelerometrici Italiani relativi al periodo 1972-2004"Published5.2. TTC - Banche dati di sismologia strumentaleope