The lower hemisphere projection of the P- and T-axes of the focal mechanism of 34 theoretical events, each consisting of ten first-motion polarities which were inverted for focal mechanisms using the method of Horiuchi et al. (1995). The solid dots are the locations of the estimated P-axes, the triangles are those of the T-axes. The large solid dot and triangle are the P- and T-axis, respectively, of the focal mechanism that was used to generate the theoretical data set. The maximum epicentral distance used for generating the data sets is shown above the spheres.