Figure 11. Samples of 20 response spectra from magnitude 6.5 earthquakes with a source-to-site distance of 8 km. The simulated spectra use means and variances from Abrahamson and Silva (1997). (a) Simulated spectra using correlation coefficients equal to zero between all periods. (b) Simulated spectra using correlation coefficients equal to one between all periods. (c) Simulated spectra using correlation coefficients from equation (9). (d) Real spectra from recorded ground motions with magnitude 6.5 and distance 8 km.