BASS, an alternative to ETAS

Abstract

The epidemic type aftershock sequence (ETAS) model has been widely used to model the statistics of seismicity. An essential feature of the ETAS model is the concept of generations of aftershocks. A mainshock has primary aftershocks, the primary aftershocks have secondary aftershocks, and so forth. In this paper, we introduce the branching aftershock sequence (BASS) model as an alternative to ETAS. The BASS model is fully self‐similar whereas the ETAS model is not. Furthermore, the ETAS model requires the specification of branching (parent‐daughter) ratios, while the BASS model instead utilizes Båth's law. We also show that the branching statistics in the BASS model are identical to the self‐similar Tokunaga statistics of drainage networks.