Stress field in northeastern Japan and its relationship with faults of recent earthquakes

Earth, Planets and Space

Table 1 Slip tendency (ST) for Eastern margin of the Japan Sea (EMJS) calculated using focal mechanism

Event	Fault model	Dip direction	Stress field	\(Ts\) best	\(Ts\) error
Shakotan-Oki earthquake	Fukao and Furumoto (1995)	East	1	0.953	0.944 < \(Ts\) < 0.993
Shakotan-Oki earthquake	Satake (1986)	West	1	0.759	0.673 < \(Ts\) < 0.915
Hokkaido Nansei-Oki earthquake	Tanioka et al. (1995) MTRF	East	2—All	0.601	0.597 < \(Ts\) < 0.613
		West	2—All	0.965	0.965 < \(Ts\) < 0.975
		East	2—North	0.619	0.612 < \(Ts\) < 0.645
		West		0.976	0.975 < \(Ts\) < 0.991
		East	2—South	0.611	0.603 < \(Ts\) < 0.637
		West		0.950	0.950 < \(Ts\) < 0.964
	Tanioka et al. (1995) CMT	East	2—All	0.947	0.943 < \(Ts\) < 0.960
		West		0.431	0.412 < \(Ts\) < 0.488
		East	2—North	0.815	0.787 < \(Ts\) < 0.996
		West		0.371	0.370 < \(Ts\) < 0.374
		East	2—South	0.955	0.953 < \(Ts\) < 0.964
		West		0.440	0.409 < \(Ts\) < 0.531
Nihonkai-Chubu earthquake	Satake (1985)	East	3—North	0.915	0.914 < \(Ts\) < 0.934
		West	3—North	0.429	0.424 < \(Ts\) < 0.443
		East	3—Middle	0.850	0.836 < \(Ts\) < 0.975
		West	3—Middle	0.506	0.503 < \(Ts\) < 0.514
		East	3—South	0.934	0.908 < \(Ts\) < 0.994
		West	3—South	0.609	0.601 < \(Ts\) < 0.622
Oga earthquake	Sato (1993)	East	4	0.914	0.902 < \(Ts\) < 0.930
Oga earthquake	Sato (1993)	West		0.805	0.833 < \(Ts\) < 0.805
Niigata earthquake	Hirasawa (1965)	East	6	0.944	0.944 < \(Ts\) < 0.971
Niigata earthquake	Hirasawa (1965)	West		0.691	0.660 < \(Ts\) < 0.782
Yamagata-Oki earthquake	F-net	East	7	0.905	0.905 < \(Ts\) < 0.906
Yamagata-Oki earthquake	F-net	West		0.805	0.833 < \(Ts\) < 0.805

ST value (\(Ts)\) error is calculated using the uncertainty of each stress ratio. Bold numbers indicate ST best values of \(Ts>0.7\). The number and letter codes in the stress field correspond to the subareas identified in Fig. 5