The Effects of Travel Path and Source Structure on the Character of Regional Distance Seismograms from Nuclear Explosions
Abstract
A comprehensive or low-yield threshold test treaty will require monitoring at regional distances, and the seismograms are very difficult to deterministically model. The character of the phases Pg and Lg shows a very strong dependence on travel path. We have conducted a number of observation- based experiments to develop empirical path corrections or scaling relations for regional phase excitation and propagation. The gross crustal structure of the western syntaxis was determined and the blockage of Pg and Lg in the region was studied empirically. Eighteen events from the 1986 Chalfant Valley earthquake sequence were used to examine the effects of source magnitude, depth, and rock properties on the regional distance spectra of Pg, Lg, and Pn. For all three variables, the spectral ratios discriminant behaves in a linear fashion. We also reviewed the effects of tectonic release on seismic body waves generated by underground nuclear explosions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 27, 1991
- Accession Number
- ADA256678
Entities
People
- Terry C. Wallace
Organizations
- University of Arizona