Before revision:  To ensure the accuracy of numerical solutions of the three space dimensional (3D) elastic wave equation in complex geometries, we discretise the 3D elastic wave equation with a pair of non-central (upwind) finite-difference stencils, on boundary-conforming curvilinear meshes.
After revision:  To ensure the accuracy of numerical solutions of the three space dimensional (3D) elastic wave equation on boundary-conforming curvilinear meshes.