Figure 2
Record section showing the vertical component ground velocity for all 400 seismic stations, bandpass-filtered between 1–2 Hz (that provides the best visual signal-to-noise ratio). All traces are displayed and no selection was made. Each trace/station is normalized to its individual maximum. The seismic and the three separate acoustic phases are highlighted. Time 0 denotes the origin time of the explosion (03:11:45 UTC). The search windows for phases 1, 2 and 3 are marked by red, blue and green lines, respectively. The corresponding velocities are: Phase 1 310–340 m/s, Phase 2 270–300 m/s, Phase 3 240–260 m/s (see also Table 1).
