Regional Seismic Wave Propagation
Abstract
In a review of studies on the seismic phase Lg. we describe its particle motion, dispersion, spectral content, mode of propagation, and magnitude-scale; we also tabulate the regional velocity, attenuation, and propagation efficiency for this seismic phase. The characteristics of Lg-wave propagation in the eastern United States are compared with those in different regions of the Soviet Union. Possible discriminants such as Lg vs. P amplitudes, Lg/P amplitude ratios as a function of distance, and Lg energy ratios are found, similar to attenuation and group velocity, to be highly dependent on the propagation path. The valid application of these quantities to the problem of earthquake-explosion discrimination will therefore require regional studies more detailed than previously assumed. A re-evaluation of the magnitude-yield relation and an examination of physical parameters which may be relevant to the estimated yield of underground nuclear explosions were performed. The preliminary results indicate that the sub m sub b vs. yield relation shows regional differences and dependence on the source medium, and the collapse volume and the diameter of the collapsed crater are usually proportional to the estimated yield.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1980
- Accession Number
- ADA095851
Entities
People
- Paul W. Pomeroy
- Thomas C. Chen