  This paper presents a high-order discontinuous Galerkin (DG) scheme for the
simulation of wave propagation through coupled elastic-acoustic media. We use a
first-order stress-velocity formulation, and derive a simple upwind-like
numerical flux which weakly imposes continuity of the normal velocity and
traction at elastic-acoustic interfaces. When combined with easily invertible
weight-adjusted mass matrices, the resulting method is efficient, consistent,
and energy stable on curvilinear meshes and for arbitrary heterogeneous media,
including anisotropy and sub-cell (micro) heterogeneities. We numerically
verify the high order accuracy and stability of the proposed method, and
investigate its performance for applications in photoacoustic tomography.
