Fault volume digital twin to reproduce the full slip spectrum, scaling and statistical laws

Abstract:

Earthquake faults exhibit complex behavior ranging from slow creeping movements to fast destructive ruptures, but the physical mechanisms underlying this spectrum remain unclear. We investigate whether the geometric arrangement of smaller fractures around a main fault — called the “damage zone" — can explain these diverse slip behaviors. We develop computer simulations that incorporate both a rough main fault and surrounding networks of fractures, all governed by the same frictional properties. We find that geometric complexity alone reproduces the full spectrum of fault slip observed in nature — from barely detectable slow slip events to regular earthquakes — without requiring spatially varying friction or fluid pressures. Our simulations naturally generate realistic aftershock sequences following Omori’s law, earthquake size-frequency distributions matching the Gutenberg-Richter relation, spatiotemporal clustering of seismicity, and complex source time functions resembling tectonic tremor. This fault volume model serves as a digital twin that can generate physically consistent synthetic earthquake catalogs for algorithms, testing how faults respond to external perturbations like tidal stresses or fluid injection, and developing improved methods for interpreting seismic and geodetic observations. Our results demonstrate that the network of small fractures surrounding major faults provides a fundamental organizing principle for fault dynamics, offering a geometric foundation upon which frictional and hydraulic effects can be evaluated.

Short bio:

I am a senior CNRS Research Scientist (Directeur de Recherche) working at the Laboratoire de Géologie in Ecole Normale Supérieure and a teaching professor at Laboratoire de Mécanique Solides, Ecole Polytechnique. I work mainly at the interface between Earthquake Physics and Solid Mechanics making occasional excursions into Rock Mechanics, Tectonics and Seismology. I obtained my B. E. in Civil Engineering from the National Institute of Technology Karnataka, India followed by a Ph. D. from Harvard University and then I did postdoctoral work at Caltech and the University of Southern California.