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

Technical Report · Mon Apr 27 00:00:00 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
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

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