The near-trench coseismic rupture behavior of the 2011 Tohoku-Oki earthquake remains poorly understood due to the scarcity of near-field observations. This study uses differential bathymetry estimates with improved horizontal resolutions to investigate near-trench coseismic slip behaviors. A velocity-strengthening behavior in the shallow fault is observed in the main rupture region, contrasting with seafloor uplift that inverts near the backstop interface outcrop, revealing significant off-fault deformation. Inelastic deformation is suggested as the predominant factor in near-trench tsunami excitation. Large trench-bleaching rupture is observed north of 39°, defining the main rupture region's northern extent. The study reveals striking spatial heterogeneity in shallow rupture behavior.
