  We introduce an efficient and accurate staggered-grid finite-difference
(SGFD) method to solve the two-dimensional elastic wave equation. We use a
coupled first-order stress-velocity formulation. In the standard implementation
of SGFD method the same SGFD operator is used to approximate the spatial
derivatives. However, we propose a numerical method based on mixed SGFD
operators which happen to be more efficient with similar accuracy in comparison
to uniform SGFD operator. We refer the proposed method as the non-balanced SGFD
numerical scheme which means combining high-order SGFD operators with
second-order SGFD operators. A very care attention is directed at the
derivation of the SGFD operator coefficients. The correctness of proposed
scheme is proven by dispersion analysis. Through SGFD modeling examples, we
verify/demonstrate that the proposed non-balanced operator offers a similar
level of accuracy with a cheaper computation cost compared to the more
expensive balanced SGFD method.

Numerical Analysis;Numerical Analysis;Geophysics