A probabilistic view on rupture predictability: all earthquakes evolve similarly

TL;DR

This paper introduces a probabilistic framework for assessing earthquake rupture evolution, revealing that predicting the final earthquake size early in the rupture process is fundamentally limited, with implications for early warning systems.

Contribution

It provides a novel probabilistic approach to evaluate rupture evolution and demonstrates that early prediction of earthquake size is not feasible, based on real-time seismic data.

Findings

Differentiation between rupture sizes occurs only after half the rupture has happened.

Early rupture predictability is fundamentally limited.

Universal initiation behavior observed for small and large ruptures.

Abstract

Ruptures of the largest earthquakes can last between a few seconds and several minutes. An early assessment of the final earthquake size is essential for early warning systems. However, it is still unclear when in the rupture history this final size can be predicted. Here we introduce a probabilistic view of rupture evolution - how likely is the event to become large - allowing for a clear and well-founded answer with implications for earthquake physics and early warning. We apply our approach to real time magnitude estimation based on either moment rate functions or broadband teleseismic P arrivals. In both cases, we find strong and principled evidence against early rupture predictability because differentiation between differently sized ruptures only occurs once half of the rupture has been observed. Even then, it is impossible to foresee future asperities. Our results hint towards a universal initiation behavior for small and large ruptures.