What can surface slip distributions tell us about fault connectivity at depth?

Fault systems with stepovers and gaps along strike are ubiquitous in nature, and many modern earthquakes (e.g. 1992 Landers, 1999 Hector Mine, 2016 Kaikoura, and 2019 Ridgecrest) have shown that ruptures can readily propagate across some disconnections, while being halted by others. It is quite possible, however, that many faults that appear discontinuous at the surface are in fact connected at depth, facilitating through-going rupture, and potentially increasing earthquake size. The present work explores whether the mapped surface slip in an earthquake is indicative of the connectivity of the fault system at depth. If there is a signal of subsurface connectivity in the surface slip pattern, then the connectivity of the system could potentially be inferred. Through 3D Dynamic rupture modeling of faults with along-strike gaps of various depths, I explore whether the amplitude or the spatial distribution of slip after an earthquake could be used to diagnose fault connectivity at depth. I ...