Ground Truth of Surface Rupture and Very-Near-Fault Ground Motion from Video, Seismic and Field Data

Seismic radiation and dynamic faulting have rarely been observed concurrently, limiting observational constraints on earthquake rupture processes and seismic hazards. Here we report the first directly validated observation of both surface rupture and strong-motion generation captured by a security camera and independently corroborated by nearby seismic records and field measurements during and after the 2026 Kumamoto, Japan, earthquake. Image-retrieved displacement time series matched nearby seismic records. We further find that the very-near-fault ground motion comprised two velocity pulses generated by subsurface and surface fault rupture, respectively, with comparable amplitudes (~1 m s -1 ) and durations (~1 s). The pulse characteristics may reflect the depth-dependent variations in seismic velocities and stress conditions across a sedimentary cover overlying the basement rock. These observations provide rare constraints on the coupling between dynamic faulting and seismic radiation, offering new insights into earthquake source physics and seismic hazard assessments near faults.