Fig. 4
From: An approach to source characterization of tremor signals associated with eruptions and lahars
Cumulative source amplitude estimation. a Band-pass-filtered (5–10 Hz) vertical velocity seismogram recorded at station BBIL during the eruption episode on 16–17 March 2013. b Envelope of seismogram in a corrected for geometrical spreading and medium attenuation (source amplitude function). c Time integration of seismogram in b (thick line) and the linear trend estimated from pre-tremor noise (thin line). Offset value from trend line at the end of the tremor (arrows) was regarded as the cumulative source amplitude