Abstract:Fault slip inversion can be represented by a regularization problem constrained with inequalities.Based on the improved MCMC approach, we invert for coseismic fault slip distribution of the 2015 Nepal megathrust event from GPS observations. Results show that the slip concentrates at a region eastward to the epicenter, near Kathmandu, with a maximum of 7 m. The slip errors statistically obtained by resampling model space are about 10% of slip. The seismic moment is 7.67×1020 Nm, equivalent to MW7.86, consistent with that from other research. The modeled GPS displacements agree well with the observations. Our results demonstrate that the improved MCMC method is appropriate for fault slip inversion from geodetic data and especially can give the slip errors statistically.