Double seismic zone and seismicity in the mantle wedge beneath the Ogasawara Islands identified by an ocean bottom seismometer observation

Earth, Planets and Space

Table 1 Parameters of OBS stations used in this study

Station	Latitude (N)		Longitude (E)		Depth (m)	Observation period	ΔTps-p (s)	Pcor (s)	Scor (s)	σ_p (s)	σ_s (s)
Station	(°)	(min)	(°)	(min)	Depth (m)	Observation period	ΔTps-p (s)	Pcor (s)	Scor (s)	σ_p (s)	σ_s (s)
A	27	51.0	140	49.7	3270	15 Jul. to 3 Oct. 2015	0.99	0.070	− 0.319	0.281	0.462
B	27	14.3	140	48.0	1219	21 Jun. to 28 Sep. 2015	0.95	1.274	0.296	0.092	0.000
C	27	15.1	140	49.4	944	21 Jun. to 2 Oct. 2015	0.86	1.493	2.594	0.141	0.246
D	27	17.8	140	52.6	1139	21 Jun. to 13 Sep. 2015	0.84	1.387	2.167	0.078	0.301
E	27	16.0	140	55.9	1206	21 Jun. to 28 Sep. 2015	1.04	1.248	1.802	0.188	0.532
F	27	12.2	140	52.2	922	21 Jun. to 18 Sep. 2015	1.11	1.517	1.192	0.288	1.527
G	26	45.0	140	49.8	2127	15 Jul. to 9 Oct. 2015	0.93	0.448	0.233	0.209	0.462
H	27	42.1	141	36.0	4144	15 Jul. to 23 Sep. 2015	1.28	− 0.473	− 1.900	0209	0.430
I	27	15.1	141	36.1	4043	15 Jul. to 5 Oct. 2015	0.60	− 0.451	− 1.650	0.209	0.534
J	26	48.1	141	36.0	3751	15 Jul. to 10 Oct. 2015	1.13	− 0.890	− 2.064	0.204	0.391
K	27	24.0	142	39.0	2783	15 Jul. to 4 Oct. 2015	0.72	0.160	0.418	0.228	0.589
L	26	51.0	142	38.9	2756	15 Jul. to 9 Oct. 2015	0.85	− 0.165	− 0.703	0.352	0.737
X (Chichijima)	27	5.7	142	11.1	− 145	–	–	1.574	3.397	0.349	0.690
Y (Hahajima)	26	38.0	142	10.5	− 108	–	–	1.194	2.521	0.515	0.631

ΔTps-p, arrival-time difference between the PS and P phases; Pcor, final station correction for the P phase; Scor, final station correction for the S phase; σ_p, standard deviation of the P-phase arrival time; σ_s, standard deviation of the S-phase arrival time