1. A computer-implemented method for analyzing a volume composed of voxels of seismic data representing a subsurface region for presence of a hydrocarbon system or a particular play, comprising: partitioning the seismic data volume to form a plurality of segments; and ranking the plurality of segments for presence of a hydrocarbon system or the particular play based at least partly on prospectivity scores for the voxels of seismic data in each segment; wherein the prospectivity score is based on computation of at least two attributes that relate to different elements of a hydrocarbon system or of the particular play.