RETAS: a restricted ETAS model inspired by Bath’s law

A version of the restricted trigger model is used to analyse the temporal behaviour of some aftershock sequences. The condi-tional intensity function of the model is similar to that of the Epi-demic Type Aftershock-Sequence (ETAS) model with the restric-tion that only the aftershocks of magnitude bigger than or equal to some threshold Mtr can trigger secondary events. For this reason we have named the model restricted epidemic type aftershock-sequence (RETAS) model. Varying the triggering threshold we examine the variants of the RETAS model which range from the Modified Omori Formula (MOF) to the ETAS model, including such models as limit cases. 1