GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 2.1 311 dell’affidabilità delle stime di pericolosità sismica, in grado di fornire risultati che permettano al progettista di conoscere la variabilità delle azioni sismiche di progetto e conseguentemente adottare i margini di sicurezza ritenuti più opportuni in relazione alla natura e importanza dell’opera. Bibliografia Barani S., Spallarossa D., Bazzurro P.; 2009. Disaggregation of probabilistic ground motion hazard in Italy . Bulletin of the Seismological Society of America, 99: 2638-2661. Bindi D., Pacor F., Luzi L., Puglia R., Massa M., Ameri G., Paolucci R.; 2011. Ground motion prediction equations derived from the Italian strong motion database . Bulletin of Earthquake Engineering, 9(6): 1899-1920. Cornell C.; 1968. Engineering seismic risk analysis. Bulletin of Seismological Society of America, 58(5): 1583- 1606. Crowley H., Stucchi M., Meletti C., Calvi G.M., Pacor F.; 2009. Revisiting Italian design code spectra following the L’Aquila earthquake . Progettazione Sismica, 3: 73-81. http://shakemap.rm.ingv.it Iervolino I.; 2013. Probabilities and fallacies: why hazard maps cannot be validated by individual earthquakes . Earthquake Spectra, 29(3): 1125-1136. Meletti C., Galadini F., Valensise G.; 2008. A seismic source zone model for the seismic hazard assessment of the Italian territory . Tectonophysics, 450: 85–108. RovidaA., Locati M., Camassi R., Lolli B., Gasparini P.; 2016: CPTI15, the 2015 version of the Parametric Catalogue of Italian Earthquakes. Istituto Nazionale di Geofisica e Vulcanologia. doi :http://doi.org/ 10.6092/ INGV.IT- CPTI15. Probability and strong earthquakes from low earth orbit satellites C. Fidani 1,2,3 1 Central Italy Electromagnetic Network, Fermo, Italy 2 GEA Observatory, Foligno, Italy 3 SARA Electronic instruments, Perugia, Italy NOAApolar orbiting satellite electron flux data have been studied for their time correlations with earthquakes. Electron and proton bursts have also been studied when precipitating into the atmosphere, in order to distinguish correlations with seismic activity from seasonal variations of particle fluxes and solar activity. Data from the dusk/noon NOAA-15 have been analysed using a set of adiabatic coordinates. Specifically, electron and proton data from July 1998 to December 2014 have been compared with nearly 1,500 main shocks occurring worldwide during the same period, all with magnitudes greater than or equal to 6. When considering 30 - 100 keV precipitating electron bursts, detected by the vertical NOAA-15 telescope and earthquake epicentre projections at altitudes greater than 1,400 km, a significant correlation was observed. The electron precipitation excesses were detected 2 - 3 hours prior to large seismic events. The correlation was analysed in time interval resolutions. The minimum considered time interval was 20 minutes, because this was the maximum duration of detection relative to a single semi-orbit, where the satellite crosses the magnetic conjugate points of a geomagnetic field line. The maximum considered time interval was 3 hours, as it was the minimum time definition of the Ap index, which was used to exclude particle data. The calculated correlation resulted stable for all these time intervals. Three correlation plots are reported in Fig. 1, where the time intervals were chosen to be 0.5, 1 and 2 hours in a ±1 days analysis, with an earthquake altitude projection of 2,400 km. The three plots, reported in Fig. 1, increase the precision of the correlation time: between 2 - 2.5 hours.