Fig. 4From: Waveform inversion of the ultra-long-period seismic event associated with ground tilt motion during an eruption of Mount Kusatsu–Shirane, Japan, on January 23, 2018Low-pass-filtered records. a Low-pass-filtered (10-s) velocity seismograms recorded by broadband seismometers, and b low-pass-filtered (10-s) tilt records converted into velocity waveforms. The red line and the gray band have the same meanings as those in Fig. 3Back to article page