Fig. 4From: Scattering strength at active volcanoes in Japan as inferred from the peak ratio analysis of teleseismic P wavesPeak amplitude ratio plotted against the estimated distance to the volcanic centre according to the 4th edition National Catalogue of the Active Volcanoes in Japan (Japan Meteorological Agency 2013). The plots are for the JMA stations at the frequency band of 2–4 Hz. JMA stations can be differentiated into ground surface (red) and borehole (blue) stations. Stations with green symbols are not classified on the JMA website. Also shown are peak ratios at Hi-net borehole stations that are within 20 km of volcanoes (Nishimura 2012). Overall, the JMA ground surface stations show larger peak ratios than their borehole counterparts. For the JMA borehole stations, we see an ostensible decay in peak ratio with distance. This pattern is continued by the Hi-net stationsBack to article page