Use of P Coda for Explosion Medium and Improved Yield Determination

摘要

Spectral analyses of P and P coda on teleseismic recordings of nuclear explosions at Yucca Flats and Pahute Mesa regions of the Nevada Test Site (NTS) seem to provide explosion source medium information. The spectral ratio P/P-coda on short-period vertical component records at NORSAR shows positive correlation with explosion medium velocity. It seems that the initial P from generally shallower explosions within a low velocity medium experiences significantly lower scattering Q (and perhaps also inelastic Q) as compared to generally deeper explosions in a high velocity medium. Near-source scattering of explosion-generated Rayleigh waves into teleseismic P also appears to play an important role. (Author)