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

TL;DR

This paper uses a physical earthquake model and a novel technique to directly observe causal links in plastic events, validating statistical tools like the Nearest-Neighbor metric for distinguishing aftershocks from independent earthquakes.

Contribution

It provides the first direct observation of causal links in earthquake-like plastic events, validating the effectiveness of statistical analysis tools used in seismology.

Findings

Aftershocks follow Omori's law in the model.

Nearest-Neighbor metric effectively separates independent events from aftershocks.

Model reproduces earthquake phenomenology accurately.

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.