Abstract: A novel method for determining and displaying the shear-velocity reflectivities of geologic formations is disclosed wherein a compression-wave common-depth-point seismic-data-gathering technique is utilized to produce both normal incidence compressional-velocity reflectivity sections and shear-velocity reflectivity sections for reflection points in given geologic formations. The subject method includes the gathering of common-depth-point information for a plurality of incidence angles, (theta) and estimating the linear coefficients (R.sub.pp,0 and R.sub.pp,1) of a linear function fitted to the amplitudes vs. sin.sup.2 (theta) measured for each point of reflection. The common-depth-point gather is conducted at angles of offset of less than 20-30 degrees such that assumptions concerning various elastic parameters: density, compressional wave velocity and shear-wave-velocity can be made which allow the application of linear fitting techniques to the gathered data.

Abstract: In a seismic data processing system, seismic data in channel-sequential format intensity modulates the electron beam of a cathode-ray tube. A photographic drum plotter provides a recording of the seismic data displayed on the face of the cathode-ray tube. A screen of multilined squares is placed in contact with the photographic film on the drum plotter so that the seismic data is recorded in a half-tone, variable-density format.