Fig. 4

Examples of focal mechanisms determined and P-wave velocity structure used in this study. a The focal mechanisms are projected onto the upper hemisphere using the stereo projection (Wulff net). Solid and open circles respectively indicate the upward (compressional) and downward (dilatational) first motions. The occurrence time is shown at the top of each focal solution, and the magnitude and score are shown at the bottom where “score” means a ratio of the data consistent to the obtained solution to the total data. b The left panel represents the P-wave velocity structure used in this study and the right panel shows the structure used in the hypocenter determination for the central Kinki district by the Disaster Prevention Research Institute, Kyoto University