This disclosure presents methods and systems for deblending blended seismic data obtained during simultaneous shooting acquisition into deblended seismic data gathers. Methods and systems iteratively separate the blended seismic data into the deblended seismic data gathers based on semblance analysis of a residual difference between the blended seismic data and the deblended seismic data gathers. Each deblended seismic data gather is associated with one of the sources and appears to have been obtained without substantial interference from seismic energy produced by other sources.