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

Earth, Planets and Space

Table 2 Slip tendency (ST) for 1833 Shonai-Oki and 2008 Nihonkai-Chubu earthquakes calculated using fault models

Events	Fault model		Dip direction	Stress field	\(Ts\) best	\(Ts\) error
Shonai-Oki earthquake	Aida (1989)	A-North	East	5—All	0.604	0.598 < \(Ts\) < 0.671
		A-South	East		0.578	0.559 < \(Ts\) < 0.623
		B	West		0.603	0.603 < \(Ts\) < 0.603
		A-North	East	5—Middle 1	0.676	0.571 < \(Ts\) < 0.834
		A-South	East		0.742	0.740 < \(Ts\) < 0.744
		B	West		0.461	0.461 < \(Ts\) < 0.461
		A-North	East	5 -Middle 2	0.619	0.588 < \(Ts\) < 0.702
		A-South	East		0.676	0.669 < \(Ts\) < 0.693
		B	West		0.536	0.534 < \(Ts\) < 0.542
Nihonkai-Chubu earthquake	Aida (1984)	North	East	3—North	0.798	0.798 < \(Ts\) < 0.798
		South	East	3—North	0.949	0.948 < \(Ts\) < 0.997
		North	East	3—Middle	0.843	0.843 < \(Ts\) < 0.905
		South	East	3—Middle	0.783	0.724 < \(Ts\) < 0.986
		North	East	3—South	0.956	0.948 < \(Ts\) < 0.987
		South	East	3—South	0.827	0.773 < \(Ts\) < 0.925
	Kosuga et al. (1986)	North	East	3—North	0.770	0.769 < \(Ts\) < 0.780
		South	East	3—North	0.766	0.752 < \(Ts\) < 0.837
		North	East	3—Middle	0.847	0.846 < \(Ts\) < 0.885
		South	East	3—Middle	0.758	0.757 < \(Ts\) < 0.879
		North	East	3—South	0.960	0.957 < \(Ts\) < 0.977
		South	East	3—South	0.900	0.873 < \(Ts\) < 0.983
	Satake (1985)	North	East	3—North	0.881	0.878 < \(Ts\) < 0.902
		South	East	3—North	0.883	0.879 < \(Ts\) < 0.933
		North	East	3—Middle	0.925	0.924 < \(Ts\) < 0.957
		South	East	3—Middle	0.800	0.782 < \(Ts\) < 0.961
		North	East	3—South	0.991	0.989 < \(Ts\) < 0.998
		South	East	3—South	0.905	0.866 < \(Ts\) < 0.994

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