GNGTS 2019 - Atti del 38° Convegno Nazionale

282 GNGTS 2019 S essione 2.1 References Boore D.M., Joyner W.B. 1997. Site Amplifications for Generic Rock Sites. Bulletin of the Seismological Society of America, Vol. 87, No. 2, pp. 327-341. Budny, M. 1984. Seismische Bestimmung der bodendynamischen Kenn-werte von oberfla ̈schennahen Schichten in Erdbebengebieten derNiederrheinnischen Bucht und ihre ingenieurseismologische Anwen-dung,Geol. Inst. Univ. Cologne, special issue 57. Hinzen, K. G., Weber, B., and Scherbaum, F. 2002. On the resolution of H/V measurements to determine sediment thickness, a case study across a normal fault in the Lower Rhine Embayment, Germany. Journal of Earthquake Engineering, 8(06), 909-926. Ibs von Seht, M. 1996. “Die seismische Bodenunruhe als Werkzeug zur Erkundung desgeologischen Untergrundes, ”Aachener Geowissenschaftliche Beitr ̈age. Kaufman, H. 1953. Velocity functions in seismic prospecting. Geophysics, 18(2), 289-297 Kottke, A. R., and Rathje, E. M. 2008. Technical manual for Strata. University of California, Berkeley. Parolai, S., Bormann, P., and Milkereit, C. 2002. New relationships between Vs, thickness of sediments, and resonance frequency calculated by the H/V ratio of seismic noise for the Cologne area (Germany). Bulletin of the seismological society of America, 92(6), 2521-2527. Schnabel, P. B., Lysmer, J., and Seed, H. B. 1972. SHAKE A Computer program for earthquake response analysis of horizontally layered sites, Report No. EERC72-12, EERC, 12 Fig. 2 - Acceleration Spectra obtained by the simulation of seismic site response considering the velocity gradients in Fig. 1. SEISMIC NOISE ANALYSIS OF BROADBAND STATIONS OF THE ITALIAN SEISMIC NETWORK BY POWER SPECTRAL DENSITY M. Catania 1,2 , A. D’Alessandro 1 , L. Greco 1 , R. Martorana 1,2 , S. Scudero 1 1 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy 2 Università di Palermo (DISTEM), Palermo, Italy Introduction. The Italian Seismic Network (IV) consists of more than 500 stations located throughout the Italian territory and affected by the different noise levels. The network performance depends on the quality of the signal recorded, especially on the signal to noise ratio. The main goal of this work has been the analyse of the frequencies content of ambient vibrations through the PSD and the PDFs, estimating the noise power level related each station. By frequency and statistical analysis, the main types and sources of microtremors are determined for each stations. For the purpose of this research, only 233 broadband sensors (with