Research suggests that the complexity of megathrust earthquakes can be explained by dynamic restrengthening and fault heterogeneity. Studies have investigated the role of various factors, including fault size, fracture energy, and plate interface frictional heterogeneities, in shaping earthquake behavior. The findings appear to be based on analyses of specific earthquakes, including the 2011 Tohoku-Oki and 2016 Kaikōura earthquakes, and may have implications for understanding seismicity and tsunami hazard.