Elastic wavefield imaging with scalar and vector potentials

We demonstrate reverse-time imaging using multicomponent elastic wavefields. The elastic data are used as boundary conditions for a numeric solution to the elastic wave-equation solved using a staggeredgrid finite-difference implementation. P and S components are not separated from recorded data, but are extrapolated together as part of a vector wavefield. A straightforward extension to the cross-correlation imaging condition used for imaging scalar wavefields leads to images hard to interpret, since P and S wavefield components are mixed on the vertical and horizontal projections of displacement fields. We use an alternative imaging condition based on elastic potentials, which reduces cross-talk and leads to images that are easier to interpret, since reflections of different wave modes are separated from one-another.