an apparatus and method use a hybrid absorbing element defined by a novel implementation of perfectly matched layer and infinite element concepts to model time - domain and frequency domain wave propagation finite element calculations . the hybrid absorbing element comprises three or more semi - infinite facets providing an essentially reflectionless interface for outgoing waves . perfectly matched layer conditions are coupled to finite - element wavefield computation regions and infinite element conditions , which effectively disperse advancing waves at infinity . the disclosed apparatus and method result in the rapid attenuation of waves arriving at arbitrary angles , leading to elimination of reflection artifacts . the hybrid absorbing element modeling approach reduces memory usage and related computational costs , especially when applied to large three - dimensional models and simulations and to large - scale simulations on massively parallel computing structures , cloud resources , or similar clustered or distributed compute and storage resources . the hybrid absorbing element can use a lumped , diagonal inertial operator for compatibility with explicit time - domain computations .