Parsimonious staggered grid finite‐differencing of the wave equation

A parsimonious staggered grid differencing scheme is presented which requires less storage than the conventional staggered grid method. For three dimensional elastic wave propagation, this scheme only stores displacement components, not stress, and so requires 66% of the memory needed by the standard staggered grid method. The storage requirement is the same as the 2–2 differencing scheme used by Kelly et al. (1976) for the second‐order wave equation. Its advantage is that it is stable and accurate for media with fluid‐elastic contacts and for a wide range of Poisson ratios. A disadvantage is that its computer programming is more involved.