Depth‐Dependent Aftershock Trigger Potential Revealed by 3D‐ETAS Modeling

Abstract

is a widely used stochastic point process model for describing the distribution and clustering of earthquakes in space and time. According to the ETAS model, any earthquake, irrespective of its size, can trigger other (larger or smaller) earthquakes. This model fits the earthquake rate as a linear superposition of a constant background rate and decaying rates of ongoing aftershock sequences triggered by past events, where the expected number of triggered events (aftershock productivity) is an exponential function of magnitude, the temporal decay follows the Omori-Utsu law (Utsu, 1961), and the aftershocks spatial distribution is usually described by an isotropic powerlaw decay as a function of the epicentral distance to the source.In the past decades, the ETAS model has been widely used and further developed in many applications (e.g.,