Analysis of selected seismic events from Asia in a seismic discrimination context. Technical report

Technical Report · Thu Sep 21 04:00:00 EDT 1978

OSTI ID:6693697

Sobel, P A; von Seggern, D H

This study examines earthquakes in Kamchatka, the Tien Shan, the Pamirs, the Baikal rift zone, and the Caucasus and explosions in the Aleutians, East Kazakh, West Kazakh, Southwest Russia, Lop Nor, and Baikal in a seismic discrimination context. Because of their low magnitudes (m sub b from 4.2 to 6.0 and M sub s from 3.2 to 5.8) and their varying propagation effects, it was impossible on the basis of first motions or LR amplitudes to determine source mechanisms for most of the earthquakes. Seismograms from the arrays ALPA, LASA, and NORSAR, the HGLP and the WWSSN stations were analyzed for m sub b, M sub s, corner frequency, long-period spectral level, long-period and short-period body-wave excitation, complexities, spectral ratios, radiation patterns, depth of focus, and higher-mode surface waves. The major successful discriminants for our data set were found to be M sub s-m sub b and identification of pP. In a stepwise linear discrimination analysis using the discrimination parameters M sub b, M sub s, corner frequency, complexity, spectral ratio, and long-period spectral level, the earthquakes were separated from the explosions with high confidence. In addition, some separation by region was evident for the earthquakes alone.

• Research Organization: Teledyne Geotech, Alexandria, VA (USA). Seismic Data Lab.
• OSTI ID: 6693697
• Report Number(s): AD-A-085879
• 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
DETECTION
EARTHQUAKES
MEASURING INSTRUMENTS
NUCLEAR EXPLOSION DETECTION
SEISMIC ARRAYS
SEISMIC DETECTION
SEISMIC DETECTORS
SEISMIC EVENTS
SEISMOGRAPHS