Rupture phases reveal geometry-related rupture propagation in a natural earthquake

Understanding and deciphering wiggles from seismograms has been a long endeavor to understand the internal structure of the Earth and to explore earthquake source properties. Here, we make an attempt to decipher the continuous rupture phases as large near-fault velocity pulses along the East Anatolian Fault in the 2023 moment magnitude ( M w ) 7.8 Kahramanmaraş, Türkiye, earthquake. Through data analysis and dynamic rupture simulations, we robustly identify the transient supershear rupture on a segment with flat fault trace and rupture deceleration at fault bends. Our study highlights the complexity and superior application of near-fault data for understanding earthquake dynamics.