An effective-medium theory used to upscale sonic-log data for synthetic seismogram manufacture. Involves harmonic averaging to find the anisotropic elastic parameters that characterize seismic-wave propagation at low frequencies in a layered medium.
Named for George Backus, brother of Milo Backus.
- ↑ Backus, G., 1962. Long-wave elastic anisotropy produced by horizontal layering: J. Geoph. Res., 67(11), 4427.