Direct estimation of earthquake source properties from a single CCTVcamera (2025 Mw 7.7 Mandalay earthquake, Myanmar)

We present the analysis of the first known video of co-seismic slip on a natural fault. It was captured during the 2025 Mw 7.7 Mandalay earthquake (Myanmar) by a CCTV camera located a few meters away from the fault. By direct image analysis of the footage, we measure the slip and slip-rate functions from the natural coseismic rupture. The results show that the rupture propagated as a slip-pulse, with a local slip duration of 1.4 s and a maximum slip rate of 3.5 m/s ± 20%. We then fit two steady-state slip-pulse models to the measured slip-rate function, allowing us to estimate the mechanical properties of the fault: the slip-stress curve, the slip-weakening distance, the breakdown work and the energy release rate. This study shows the value of direct on-fault slip measurements for constraining those mechanical parameters, that are key inputs in dynamic rupture models.