Numerical modeling of seismic wavefields using finite-difference or fi
nite-element methods requires truncation of the model to finite comput
ational domains. It is well known that the edges of such truncated mod
els give boundary reflections on the synthetic seismograms, An essenti
al step to successful numerical modeling is to eliminate these reflect
ions. We present a simple scheme that eliminates such boundary reflect
ions when computing synthetics. We also demonstrate the efficiency and
robustness of our method on a variety of geological models.