Fig. 6

Yield stresses (red) and stress drops (blue) as a function of \(\sigma_{3}\) for a \(\sigma_{1}\) value of a 100, b 300, and c 500 MPa. \(S_{\text{H}}\) was set to be 2.0 in the calculations of the yield stresses. Triangles and circles indicate the values of the Hinagu and Futagawa faults, respectively. Crosses indicate the maximum and minimum values of the junction elements for each \(\sigma_{3}\). For low \(\sigma_{3}\) values indicated in light gray, \(\tau^{\text{r}}\) is much higher on the Futagawa fault than on the Hinagu fault, and thus, the seismic moment (i.e., stress drop) in the Futagawa fault should have been larger than the observed seismic moment even if the stress drop on the Hinagu Fault is zero. For low \(\sigma_{3}\) values indicated in dark gray, the yield stress is negative. For high \(\sigma_{3}\) values indicated in gray, the regional shear stress \(\tau^{\text{r}}\) is smaller than the static shear stress change due to the three foreshocks. Therefore, white regions correspond to the feasible \(\sigma_{3}\) values. The bottom panels are enlarged figures of the white region in the top panels