none 10.1193/1.1586132 Wiley Wiley (John Wiley & Sons) 311 8415950 5867 2026012504012900184 10.1002 2026-01-25T13:10:43Z 2003-07-31T11:11:24Z 14 Earthquake Spectra Earthquake Spectra 8755-2930 1944-8201 08 2000 16 3 C. Nunziata Univ. “Federico II” di Napoli—Dipartimento di Geofisica e Vulcanologia Largo S. Marcellino 10 I‐80138 Napoli Italy G. Costa Univ. di Trieste—Dipartimento Scienze della Terra Via Weiss 4 I‐34127 Trieste Italy F. Marrara Univ. di Trieste—Dipartimento Scienze della Terra Via Weiss 4 I‐34127 Trieste Italy G. F. Panza Univ. di Trieste—Dipartimento Scienze della Terra Via Weiss 4 I‐34127 Trieste Italy ICTP SAND Group P.O. Box 586 I‐34100 Trieste Italy The seismic ground motion of a test area in the eastern district of Naples is computed with a hybrid technique based on the mode summation and the finite difference methods. Synthetic seismograms are validated with the 1980 Irpinia earthquake, a good example of strong shaking for Naples, recorded 10km from the modeled sites. Realistic SH and P‐SV wave seismograms are computed along geological cross sections representative of the area. As expected, the sedimentary cover causes an increase of the signal's amplitudes along the radial and transverse components. The spectral amplification of the vertical motion is generally negligible; instead, that of the horizontal motion ranges between 2 and 5 in the 0.7‐2.2 Hz frequency range. Average and maximum spectral amplifications are considered along the different geological cross sections and acceleration response spectra for the Irpinia earthquake are evaluated in order to formulate appropriate design spectra and improvements to the building code. 08 2000 08 2000 643 660 10.1193/1.1586132 http://onlinelibrary.wiley.com/termsAndConditions#vor http://doi.wiley.com/10.1002/tdm_license_1.1 10.1193/1.1586132 https://onlinelibrary.wiley.com/doi/10.1193/1.1586132 http://sage.cnpereading.com/paragraph/article/?doi=10.1193/1.1586132 https://onlinelibrary.wiley.com/doi/pdf/10.1193/1.1586132 https://onlinelibrary.wiley.com/doi/pdf/10.1193/1.1586132 https://pubs.geoscienceworld.org/earthquake-spectra/article/16/3/643/584775/validated-estimation-of-response-spectra-for-the