Effect of crustal structure on rayleigh waves generated by atmospheric explosions

Abstract

Theoretical seismograms are calculated at a teleseismic distance from atmospheric sources over oceanic and continental earth models. Vertical surface displacements of the fundamental and first higher‐mode Rayleigh waves are obtained for each of the models. Source altitudes range from 0.3 to 4.88 km for a 1‐kiloton nuclear explosion in a stratified thermal atmosphere. At 20‐sec period, an explosion over the oceanic model exhibits amplitudes an order of magnitude greater than the equivalent amplitudes from an explosion of the same burst height and yield over any of the three continental structures. If the differences in anelastic attenuation over the paths are included, this effect will be reversed at large enough distances.