Fig. 5

Paleostresses inferred from fault-slip data obtained from the coastal outcrop of the Akkeshi Formation (modified from Naruse and Otsubo 2011a). Lower-hemisphere, equal-area projections are shown. The symbols indicate the optimal stress solutions acquired by the multiple inversion method (Yamaji 2000; Otsubo and Yamaji 2006) and k-means clustering (Otsubo et al. 2006) with k = 6. Left and right columns correspond to σ₁ and σ₃ axes, respectively. The color of the symbol represents the stress ratio, Φ = (σ₂ − σ₃)/(σ₁ − σ₃)