Fig. 2.From: Nonlinear site response evidence of K-NET and KiK-net records from the 2011 off the Pacific coast of Tohoku EarthquakeTime-frequency analysis of the energy spectral density (ESD) of rock (a) and stiff soil sites (b). The former presents a broadband spectral content up to 10 Hz, whereas the latter shows an energy content up to 8 Hz. Note the energy burst at 2 Hz for MYG011 and at 4 Hz for MYG004 during the rupture of the second event in both stations.Back to article page