Relative Lg and P-Coda Magnitude Analysis of the Largest Shagan River Explosions
Abstract
Characteristics of P-coda and Lg measurements at the NORSAR (norwegian Seismic Array) and Graefenburg (West Germany) arrays were studied for presumed underground nuclear explosions in the Semipalatinsk region of the Soviet Union. The main objectives were to investigate the effects of the propagation paths in western Russia on the narrowband and broadband recordings of Lg at teleseismic distances and to study the relative P-coda and Lg amplitudes recorded at these two arrays for the largest (m sub b > or = 6.0) Shagan River explosions. Comparison of broadband recordings of teleseismic Lg at Graefenburg (Delta = 42 deg) with narrowband NORSAR (Delta = 38 deg) and filtered Graefenburg recordings of LG from Shagan River events reveals that Lg is more obvious, relative to the preceding P-coda, on broadband seismograms than on high-frequency seismograms. Broadband recordings of Lg at Graefenburg are about 0.5 log units stronger in the 0.2 - 1.0 Hz band than in the 0.6 - 3.0 Hz range although noise is also correspondingly higher. The early P-coda at NORSAR is stronger, relative to Lg, than that at Graefenburg. Also, the coda-envelope shapes are quite different for the two arrays.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 28, 1984
- Accession Number
- ADA151091
Entities
People
- Douglas R. Baumgardt