1. A method for de-blending seismic data associated with a subsurface of the earth, the method comprising: receiving seismic data “d” that includes shot recordings generated by plural sources that are simultaneously actuated; forming either a continuous receiver trace or trace segments by splicing together traces from the received seismic data; selecting plural overlapping spatial blocks that cover shot locations of the plural sources; assigning the shot recordings to the plural overlapping spatial blocks; determining, based on the shot recordings, a linear de-blended model “m” of the seismic data by reverse transforming data corresponding to the overlapped spatial blocks, merging traces together from all spatial blocks and applying resignature to obtain resulting traces, and re-blending the resulting traces; and generating an image of the subsurface based on the de-blended model m.