1. A computer-implemented method for analyzing a volume of seismic or seismic attribute data (the “seismic data volume”) to discover spatial location and shape of geologic features of a subsurface region, comprising: making a second-order tensor representation of the seismic data, and using a computer to perform decomposition of the tensor representation to form seismic attributes; wherein the tensor decomposition is eigenvalue decomposition, the eigenvalues being referred to as λ 1 , λ 2 , and λ 3 , and wherein the seismic attributes comprise at least one of ballness (λ 3 ), plateness (λ 2 -λ 3 ) and stickness (λ 1 -λ 2 ) and their orientations; and using the seismic attributes to interpret the seismic data volume for geologic features.