A system and computer-implemented method for determining properties of a subsurface region of interest from seismic data include obtaining seismic data and an initial earth property model, forward modeling using the initial earth property model to create modeled seismic data, transforming the modeled and actual seismic data to create frequency domain modeled and actual seismic data including amplitude portion and phase portions, measuring the misfit between the frequency domain modeled and actual seismic data to produce frequency domain residual seismic data, performing phase unwrapping of certain observed frequency components of the frequency domain residual seismic data to create an unwrapped residual phase portion, and inverting the unwrapped residual phase portion to determine desired properties of the subsurface region of interest.