Understanding Earthquake Physics with On-Fault Observatories

Men-Andrin Meier, Paul Antony Selvadurai, Luca Dal Zilio, Florian Amann, Marco Bohnhoff, Massimo Cocco, William Ellsworth, Alice-Agnes Gabriel, Satoshi Ide, Kuo-Fong Ma, Heather Savage, Mariano Supino, Elisa Tinti , Stefan Wiemer, Domenico Giardini

Earthquakes often strike without warning. Current fault monitoring infrastructure is not sensitive enough to detect signals such as accelerating fault creep or dilation, which laboratory experiments and numerical models predict may precede large earthquakes. Here we argue that a paradigm shift is needed and technically achievable: from inferring faulting processes from a distance with surface arrays, to on-fault observatories (OFOs) that measure the processes directly on faults. And from accidental fault activation to controlled fault activation experiments. We discuss how the resulting observations could solve long-standing earthquake physics questions, and pave the way for more powerful earthquake risk mitigation strategies.