Figure 4: Radial (R) and tangential (T) ground-velocity components of three of the larger aftershocks; see annotated events in Figure 1A. All records have been low-pass filtered at 0.25 Hz and plotted at the same time scale with a 70-s duration. The records of each event are plotted at the same amplitude scale and the peak amplitude is annotated with the magnitude and epicentral distance on the left.