Table 1 Characteristic precursory phenomena
Method | Spatial extent | Duration |
|---|---|---|
b-value method | Area of 0.3° × 0.3° containing a part of the source zone of the Kumamoto mainshock | Unknown |
RTM-algorithm | Area of 2° × 3° between the Kumamoto and Off Satsuma Peninsula mainshocks | 1.5 years for the Kumamoto mainshock (1 year for the Off Satsuma Peninsula mainshock) |
Z-value method | Area with R = 100 km between the Kumamoto and Off Satsuma Peninsula mainshocks | 1.5 years for the Kumamoto mainshock (1 year for the Off Satsuma Peninsula mainshock) |
Seismicity density analysis | Area with Δr = 8–40 km containing a part of the source zone of the Kumamoto mainshock | 3 years or longer for the Kumamoto mainshock |