Direct observations of causal links in plastic events validates statistical analysis tools for seismology

Abstract

Earthquakes are complex physical processes driven by the stick-slip motion of a sliding fault. After the main quake, a series of aftershocks typically follows. These are loosely defined as events that follow a given event and occur within prescribed space-time windows. In seismology, it is however impossible to establish a causal relation and the popular Nearest-Neighbor metric is commonly used to distinguish aftershocks from independent events. Here we employ a model for earthquake dynamics, previously shown to be able to correctly reproduce the phenomenology of earthquakes, and a technique that allows us to separate independent and triggered events. We show that aftershocks in our catalogue follow Omori's law and we employ the model to show that the Nearest-Neighbor metric is effective in separating independent events from aftershocks.