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 inverse method is to find optimum model parameters from geodetic data, combining prior information of both the smoothness of fault slip and maximum likelihood method with Akaike' s Bayesian Information Criterion (ABIC). We apply Yabuki & Matsu'ura's inverse method to estimate the co-seismic slip distribution of the 2011 Tohoku-Oki M(w)9. 0 earthquake on a curve fault model from GPS observation data. The estimated maximum slip is 3 5 m. The strong slips are delineated in an area with depth less than 30 km, shallower than the seismic focus. The biggest ruptures concentrate in an area with depth about 20 km. The total moment is about 3. 63 x 10(22) N . m. The corresponding moment magnitude is M(w)9. 0. Our simulation results confirm that the Yabuki & Matsu'ura's inversion method is suitable for faults with dip angle less than 40 degrees. Finally, we compute the far-field deformations in Northeast China of the 2011 Tohoku-Oki M(w)9. 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.