Fig. 3
From: Infrasonic wave accompanying a crack opening during the 2015 Hakone eruption
Seismic and microphone records at the OWD station during the rapid tilt change. The raw and band-passed signals of a a seismometer (vertical component) and b a microphone. c RMS amplitude during a 1-s moving window of the band-passed signals. d Time sequence of the tiltmeters at the KOM and KZR stations. e The microphone–seismometer correlation function with a 5-s moving window. The yellow and black broken lines show the onset of the seismic RMS amplitude and the rapid tilt change, respectively