Time Domain Waveform Inversion of Short-Period P-Waves for Nuclear Explosion Source Time Functions

摘要

This research investigates the estimation of the source time parameters of underground nuclear explosions from the waveforms of short-period teleseismic P-waves. In the simplest consideration, and when the source yield is unconstrained, there are only three source parameters, two that describe the source time function and one for the delay time of the (p)P phase. There are, of course, indications that the (p)P arrival may not have the same amplitude or shape as the direct P arrival, presumably due to anelastic or nonlinear effects between the shot point and the surface. Thus, we will also consider the effect on the waveforms of a decreased (p)P amplitude. Another parameter which has a significant influence upon the observed waveforms is t (t = travel time/Q(av). Accordingly, the variations in the source parameter estimates due to a varying t will also be addressed. (Author)