Effects of Depth of Burial and Tectonic Strain Release on Regional and Teleseismic Explosion Waveforms

摘要

The seismic motions from nonlinear two dimensional (2D) axisymmetric finite difference calculations of underground explosions are propagated to regional and teleseismic distances. Synthetic seismograms are computed and examined to study the effects of depth of burial, medium structure, and prestress on seismic waveforms. The elastodynamic representation theorem is used to couple the results of finite difference source calculations to regional Green's functions computed using a wavenumber integration algorithm. The 2D finite difference source calculations include the nonlinear effects of gravity, spall, bulking, and cracking as well as the finite extent and divergence from spherical symmetry. The results are broadband full wave regional synthetics for explosion sources with cylindrical symmetry. These theoretical seismograms are studied with regard to proposed regional discriminants between explosions and earthquakes. Explosions, Tectonic release, Depth, Burial, Finite differences, Seismic waveforms. (mjm)