SFA method applied to the SCEC catalogue: main shock magnitudes vary within [1.5;2] (plot a) up to [4;4.5] (plot f). In each plot, the upper solid curve corresponds to n_B = 0 and n_D = 0, the dashed curve corresponds to n_B = 3 and n_D = 0, while the lower solid curve corresponds to n_B = 0 and n_D = 10. Occurrences of large bursts in the time-series sometimes interrupt the power-law scaling (see plots a, b and e).