Fig. 3

Fault type classification in this study. The fault type classification scheme is similar to that of the triangle diagram proposed by Frohlich (1992), but we introduce two grades for each category based on the plunge of the axis. Grade A means that the focal mechanism has an axis with a plunge angle θ ≥ 60°, and grade B indicates a plunge angle of 45° ≤ θ < 60°