Wave‐guide effects in subduction zones: Evidence from three‐dimensional modeling

We have simulated seismic wave propagation in models of the subduction zone off the Pacific coast of Mexico using a three‐dimensional finite difference method. The results show that a significant part of the energy generated by earthquakes in the subduction zone can be trapped inside a wave‐guide generated by the low‐velocity material of the accretionary prism. The trapped waves in the simulations appear as long‐duration wave‐trains that follow the onset of the surface waves, similar to the signature of broadband seismograms recorded by stations along the Pacific coast of Mexico for subduction earthquakes.