Estimation of Co-Seismic Slip Distribution of the 2011 Tohoku-Oki Mw9.0 Earthquake Using Yabuki & Matsu'ura's Inverse Method

Yabuki & Matsu'ura's inversion method determines fault slip distribution from geodetic data utilizing the maximum likelihood method with Akaike's Bayesian Information Criterion (ABIC) under the smoothness constraint. We use this method to estimate the co‐seismic slip distribution of the 2011 Tohoku‐Oki Mw9.0 earthquake on a curved fault from GPS observation data. The result indicates that the maximum slip is 35 m, strong slips are distributed in depths shallower than 30 km above the earthquake focus, and the biggest ruptures are concentrated at a depth about 20 km. The seismic moment is about 3.63×1022 N·m, corresponding to a moment magnitude Mw9.0. Our simulation results confirm that the Yabuki & Matsu'ura's inversion method is suitable for faults with dip angle less than 40°. Finally, we compute the far‐field deformations in Northeast China caused by the 2011 Tohoku‐Oki Mw9.0 earthquake using spherical dislocation theory of Sun et al. Our theoretical predictions agree well with the observed co‐seismic displacement from China GPS Observation Network.