caa a22 4500 467935904 CHVBK 20180406152957.0 cr unu---uuuuu 170328e20060701xx s 000 0 eng 10.1007/s11069-005-0386-3 doi (NATIONALLICENCE)springer-10.1007/s11069-005-0386-3 On the Importance of Geolithological Features for the Estimate of the Site Response: The Case of Catania Metropolitan Area (Italy) [Elektronische Daten] [G. Lombardo, H. Langer, S. Gresta, R. Rigano, C. Monaco, G. De Guidi] The evaluation of seismic site response in the urban area of Catania was tackled by selecting test areas having peculiar lithological and structural features, potentially favourable to large local amplifications of ground motion. The two selected areas are located in the historical downtown and in the northern part of Catania where the presence of a fault is evident. Site response was evaluated using spectral ratio technique taking the horizontal- to-vertical component ratio of ambient noise. Inferences from microtremor measurements are compared with results from synthetic accelerograms and response spectra computed at all drillings available for this area. Such method is particularly suitable in urban areas where the nature of the outcropping geological units is masked by city growth and anthropic intervention on the surface geology. The microtremor H/V spectral ratios evaluated at soft sites located within the downtown profile tend to be smaller than that usually reported in the literature for such soils. A tendency for amplifications to peaks near 2Hz is observed only in some sites located on recent alluvial deposits. Evidences for amplifications of site effects (frequency range 4-8Hz) were observed in the sampling sites located on the fault, with a rapid decrease of spectral amplitude just a few tenths of metres away from the discontinuity. Numerical simulations evidenced the importance of geolithological features at depth levels even greater than 20-30m. Besides this, the results strongly confirm the importance of the subsurface geological conditions, in the estimate of seismic hazard at urban scale. Springer, 2006 local seismic response nationallicence microtremor nationallicence H/V spectral ratio nationallicence Catania downtown nationallicence fault zone nationallicence Lombardo G. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut Langer H. Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Catania, Italy aut Gresta S. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut Rigano R. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut Monaco C. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut De Guidi G. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut Natural Hazards Kluwer Academic Publishers 38/3(2006-07-01), 339-354 0921-030X 38:3<339 2006 38 11069 https://doi.org/10.1007/s11069-005-0386-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11069-005-0386-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lombardo G. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut NATIONALLICENCE 700 1- Langer H. Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Catania, Italy aut NATIONALLICENCE 700 1- Gresta S. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut NATIONALLICENCE 700 1- Rigano R. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut NATIONALLICENCE 700 1- Monaco C. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut NATIONALLICENCE 700 1- De Guidi G. Dipartimento di Scienze Geologiche, Università di Catania, C.so Italia, 57 95129, Catania, Italy aut NATIONALLICENCE 773 0- Natural Hazards Kluwer Academic Publishers 38/3(2006-07-01), 339-354 0921-030X 38:3<339 2006 38 11069 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer