High-frequency observations of signals and noise near RSON: implications for the discrimination of ripple-fired mining blasts

Technical Report · Mon Apr 27 04:00:00 EDT 1987

OSTI ID:6443057

Smith, A T; Grose, R D

Discrimination of large chemical explosions from possible clandestine nuclear tests is a significant issue for seismic verification. Unless discrimination is possible, the numerous mining blasts within the USSR would give ample opportunity for concealing a clandestine test. Evernden et al. (1986) advocate high frequencies as a means to detect these clandestine tests; however, mining blasts must still give a unique signature for their discrimination. Specific conditions are also necessary for high-frequency verification: low attenuation and quiet seismic stations are among the most important. In this study we address these problems under conditions representing a best case scenerio. During the summer of 1985, LLNL deployed a regional array and high-frequency station near RSON (Red Lake, Ontario, Canada) to study regional seismic signals at a low-noise site with excellent propagation characteristics, the continental shield. One objective was to evaluate the performance of regional seismic arrays and high-frequency stations in this geological environment. Using high-frequency data from mining blasts within the Masabi Iron Range in northern Minnesota (distance of 400 km), we observed the high-frequency P/sub n/ phase of ripple-fired blasts, modelled their source properties, and evaluated a possible discriminant for chemical explosions. This study suggests the existence of a distinctive signature for large chemical explosions: strong, high-frequency spectral peaks in the P spectra introduced by delay shooting or ripple-firing. Its application depends, however, on a frequency band extending to at least 35 Hz at regional distances and predictably quiet seismic sites.

• Research Organization: Lawrence Livermore National Lab., CA (USA); California Univ., Berkeley (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6443057
• Report Number(s): UCID-20945; ON: DE87009796
• Country of Publication: United States
• Language: English

Related Subjects

350300 -- Arms Control-- Verification-- (1987-)
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450300* -- Military Technology
Weaponry
& National Defense-- Nuclear Explosion Detection
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
ATTENUATION
CHEMICAL EXPLOSIONS
DETECTION
ENERGY SPECTRA
EXPLOSIONS
FREQUENCY RANGE
HZ RANGE
MEASURING INSTRUMENTS
NUCLEAR EXPLOSION DETECTION
SEISMIC ARRAYS
SEISMIC DETECTION
SEISMIC P WAVES
SEISMIC WAVES
SPECTRA