Scattering strength at active volcanoes in Japan as inferred from the peak ratio analysis of teleseismic P waves

Earth, Planets and Space

Table 1 Mean and standard deviation of peak amplitude ratios and transverse peak delay times

Frequency (Hz)	Peak ratio	Transverse peak delay time (s)	N
All JMA stations
0.5–1	0.32 ± 0.12	9.4 ± 6.3	134
1–2	0.35 ± 0.13	8.1 ± 4.2	140
2–4	0.36 ± 0.13	7.3 ± 2.8	136
4–8	0.39 ± 0.12	6.6 ± 3.0	109
JMA ground surface
0.5–1	0.34 ± 0.12	8.8 ± 6.2	77
1–2	0.40 ± 0.12	8.3 ± 4.7	82
2–4	0.42 ± 0.11	7.7 ± 3.1	79
4–8	0.43 ± 0.12	6.9 ± 2.7	58
JMA borehole
0.5–1	0.30 ± 0.11	10.4 ± 6.5	53
1–2	0.27 ± 0.09	8.0 ± 3.3	53
2–4	0.26 ± 0.09	6.7 ± 2.3	53
4–8	0.34 ± 0.10	6.3 ± 3.3	49
Hi-net all data
0.5–1	0.14 ± 0.11	10.7 ± 6.7	635
1–2	0.14 ± 0.10	8.6 ± 5.2	725
2–4	0.16 ± 0.11	7.0 ± 4.7	712
4–8	0.20 ± 0.14	6.5 ± 4.6	574

N is the number of stations available. Some stations are unclassified on the JMA website. Hi-net numbers are from Table 1 of Nishimura (2012)
We divide the data set into three categories (all JMA, ground surface, and borehole stations), as well as into different frequency bands