Exceptionally Elongated Strike‐Slip Rupture Caused by the 2025 <i>M</i> _<i>W</i> 7.8 Myanmar Earthquake

Abstract The interplay between fault geometry and rupture behavior remains poorly understood. The 2025 Myanmar earthquake ruptured the Sagaing fault, a major continental strike‐slip fault with simple geometry. We integrated geodetic and teleseismic observations to investigate its rupture process through finite‐fault kinematic inversions and back‐projection imaging. Our results show that the Myanmar earthquake ruptured bilaterally along the Sagaing fault, propagating southward from the hypocenter at a supershear speeds of 4.5–5.9 km/s and northward at a subshear speed of ∼3.1 km/s, producing a 472‐km‐long surface rupture. The aspect ratio of the rupture length to width is up to 42, the largest value ever documented, likely due to simple fault geometry and well‐connected asperities. The 2025 Myanmar earthquake, along with historical major events, reveals that the geometrically simple Sagaing fault exhibits variable rupture extent and recurrence intervals for large earthquakes due to fault segmentation.