Surface-wave generation by underground nuclear explosions releasing tectonic strain

Technical Report · Mon Nov 03 04:00:00 EST 1980

DOI:https://doi.org/10.2172/6720433· OSTI ID:6720433

Patton, H J

Seismic surface-wave generation by underground nuclear explosions releasing tectonic strain is studied through a series of synthetic radiation-pattern calculations based on the earthquake-trigger model. From amplitude and phase radiation patterns for 20-s Rayleigh waves, inferences are made about effects on surface-wave magnitude, M/sub s/, and waveform character. The focus of this study is a comparison between two mechanisms of tectonic strain release: strike-slip motion on vertical faults and thrust motion on 45/sup 0/ dipping faults. The results of our calculations show that Rayleigh-wave amplitudes of the dip-slip model at F values between 0.75 and 1.5 are significantly lower than amplitudes of the strike-slip model or of the explosion source alone. This effect translates into M/sub s/ values about 0.5 units lower than M/sub s/ of the explosion alone. Waveform polarity reversals occur in two of four azimuthal quadrants for the strike-slip model and in all azimuths of the dip-slip-thrust model for F values above about 3. A cursory examination of waveforms from presumed explosions in eastern Kazakhstan suggests that releases of tectonic strain are accompanying the detonation of many of these explosions. Qualitatively, the observations seem to favor the dip-slip-thrust model, which, in the case of a few explosions, must have F values above 3.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6720433
• Report Number(s): UCRL-53062
• 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
58 GEOSCIENCES
580201 -- Geophysics-- Seismology & Tectonics-- (1980-1989)
DATA
EARTHQUAKES
ENVIRONMENTAL IMPACTS
EXPLOSIONS
INFORMATION
MATHEMATICAL MODELS
NUCLEAR EXPLOSIONS
NUMERICAL DATA
RAYLEIGH WAVES
SEISMIC EVENTS
SEISMIC SURFACE WAVES
SEISMIC WAVES
STRAINS
THEORETICAL DATA
UNDERGROUND EXPLOSIONS