Spatiotemporal Relationship between Geodetic and Seismic Quantities: A Possible Clue to Preparatory Processes of M ≥ 6.0 Inland Earthquakes in Japan

Table 3

Contingency table showing the relationship between proposed potential conditions associated with the occurrence of M ≥ 6.0 inland mainshocks for four pairs of geodetic and seismic quantities and their actual occurrence times. The four figures for each element correspond to the following four pairs of geodetic and seismic quantities from left: the absolute value of dilatation rate and seismic energy, maximum shear strain rate and seismic energy, absolute value of dilatation rate and the number of earthquakes, and maximum shear strain rate and the number of earthquakes. A proposed potential condition occurring prior to the occurrence of inland mainshocks, Δ(no. PTN1/no. PTN2)<0, implies that the trend of no. PTN1/no. PTN2 is negative (Figure 5).

	Occurrence of inland earthquakes (M ≥ 6)	Nonoccurrence	Alarm rate (AR)
Δ(no. PTN 1/no. PTN2) < 0	5/5/4/3	7/12/7/10	0.417/0.294/0.364/0.231
Δ(no. PTN 1/no. PTN2) > 0	0/0/1/2	13/8/13/10
Success rate (SR)	1.00/1.00/0.80/0.60

Probability gains of AR and SR: 3.56/2.49/3.00/1.97 and 3.58/3.49/2.73/2.13.