Liuwei Xu, Lingsen Meng, Zhang Yunjun, Yanchen Yang, Yidi Wang, Changyang Hu, Huihui Weng, Wenbin Xu, Elizabeth Su, Chen Ji
) 7.8 Mandalay, Myanmar, earthquake ruptured ~510 km of the Sagaing fault, with a sustained supershear rupture extending ~450 km on the southern branch. Far-field Mach waves and near-field ground motion confirmed the supershear nature. This exceptionally long supershear rupture caused building collapse and soil liquefaction, as observed in satellite imagery, offering insights into the damage potential of such ruptures in urban areas. Sustained supershear propagation was facilitated by the fault's linear geometry, prolonged interseismic quiescence, favorable energy ratio, and pronounced bimaterial contrasts across the fault interface. These findings underscore the roles of fault structure, stress accumulation, and material contrasts in governing rupture dynamics, demonstrating that large-scale supershear propagation can occur in interplate continental fault systems.