Investigations of the low frequency seismic waves recorded at near-regional distances from the Non-Proliferation Experiment

Conference · Sat Dec 31 00:00:00 EST 1994

OSTI ID:96001

Patton, H J ^[1]

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1. Lawrence Livermore National Lab., CA (United States)

Seismic waves recorded at near-regional distances are used to characterize the source of the Non-Proliferation Experiment (NPE) and three selected nuclear explosions detonated in N-tunnel on Rainier Mesa. For periods longer than 5 sec, the signal-to-noise ratio is poor on most recordings of the NPE. A seismogram-stacking method is used in order to reduce background noise in coherent arrivals of Rayleigh waves. This method requires equalization of path dispersion and attenuation, which is accomplished in this study with empirical Green`s functions. The stacked, equalized Rayleigh-wave spectra are inverted, along with the spectral amplitudes of Lg waves with periods of 2-5 sec, for estimates of the seismic moment tensor. The NPE isotropic moment is 1.6 x 10{sup 14} Nt-m. The inferred static level of the reduced displacement potential is 825 m{sup 3}, which is about two times smaller than the estimate from free-field data recorded within 1 km of the NPE. Moment tensors of the NPE and nuclear explosions are asymmetric, describing prolate ellipsoids of rotation with the long axis in the vertical direction. The asymmetries are among the largest for explosions on Pahute and Rainier Mesa. The non-isotropic component is a compensated linear vector dipole (CLVD), which may represent driven block motions occurring within a conical volume of material extending from the shot point (apex) to the free surface. The CLVD source can help explain some observations of scalloping in the spectra of Lg waves and Lg spectral ratios. Seismic radiation from the NPE is virtually indistinguishable from that of nearby nuclear explosions for frequencies below 1 Hz.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• OSTI ID: 96001
• Report Number(s): CONF-9404100-; ON: DE95011413; TRN: 95:005144-0021
• Resource Relation: Conference: Symposium on the non-proliferation experiment results and implications for test ban treaties, Rockville, MD (United States), 19-21 Apr 1994; Other Information: PBD: [1994]; Related Information: Is Part Of Proceedings of the symposium on the Non-Proliferation Experiment (NPE): Results and implications for test ban treaties; Denny, M.D.; Stull, S.P. [eds.]; PB: 599 p.
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
35 ARMS CONTROL
99 MATHEMATICS
COMPUTERS
INFORMATION SCIENCE
MANAGEMENT
LAW
MISCELLANEOUS
AMMONIUM NITRATES
DETONATIONS
FUEL OILS
CHEMICAL EXPLOSIONS
COMPARATIVE EVALUATIONS
NON-PROLIFERATION TREATY
VERIFICATION
NUCLEAR EXPLOSIONS
WAVE FORMS
UNDERGROUND EXPLOSIONS
GROUND MOTION
VELOCITY
NUCLEAR EXPLOSION DETECTION
WAVE PROPAGATION
SEISMIC DETECTORS
SEISMOGRAPHS
NEVADA TEST SITE
SEISMIC SURFACE WAVES
RAYLEIGH WAVES
CALCULATION METHODS