Study of spectral nulls and scaling of P-wave spectra of Shagan River and Novaya Zemlya (USSR) explosions. Volume 3. Final report, 16 Apr 89-15 Jul 91

Technical Report · Wed Nov 13 04:00:00 EST 1991

OSTI ID:5381943

Gupta, I N; Wagner, R A

Spectral ratios P/P-coda, Pn/Lg, inter-shot ratios of P and Pn, and multichannel deconvolution are used to study spectral nulls on data from nearly 100 Shagan River and Novaya Zemlya explosions recorded at EKA, GBA, YKA, NORESS, MAJO, NORSAR, and WMQ. Spectra of P waves from Shagan River explosions show well-defined nulls due to cancellation by pP at the expected frequency of about 4 Hz for large (m sub b approximately = 6) shots, low-frequency nulls in teleseismic data related to both local geology and depth of burial, and distinct nulls at about 3 Hz in teleseismic data for large and small shots. Low-frequency P-coda appears to be due to the scattering of explosion-generated Rg. Comparison of observed data with synthetics suggests that observed P spectra vary more slowly with m sub b than predicted by commonly used scaling relationships. Analysis of data from 19 Novaya Zemlya explosions suggests that P-wave spectra of large shots have distinct spectral nulls at about 2.5-3.0 Hz, probably due to pP. P/P-coda and inter-shot ratios at common receivers provide reliable methods for estimating spectral nulls. A comparison of synthetics with the observed data suggests the amplitude ratio pP/P to be about 0.5 for large shots.

• Research Organization: Teledyne Geotech, Alexandria, VA (United States)
• OSTI ID: 5381943
• Report Number(s): AD-A-247548/1/XAB; TGAL--91-07; CNN: F19628-89-C-0063
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450300* -- Military Technology
Weaponry
& National Defense-- Nuclear Explosion Detection
ASIA
DATA ANALYSIS
DETECTION
DEVELOPED COUNTRIES
EUROPE
EXPLOSIONS
MEASURING INSTRUMENTS
NUCLEAR EXPLOSIONS
P WAVES
PARTIAL WAVES
SCALING
SCATTERING
SEISMIC ARRAYS
SEISMIC DETECTION
SEISMIC WAVES
SEISMOLOGY
UNDERGROUND EXPLOSIONS
USSR