MOESM1 of Source rupture process of the 2018 Hokkaido Eastern Iburi earthquake deduced from strong-motion data considering seismic wave propagation in three-dimensional velocity structure

Additional file 1: Fig. S1. Initial portion of the observed velocity waveforms in 0.05–20 Hz of the mainshock and an aftershock occurring at 09:48 on September 14, 2018. The blue and red inverse triangle indicates P- and S-wave onset, respectively.