Estimation of explosion moments at Mururoa and tectonic release orientations at Novaya Zemlya. Final report, July 1988-July 1989

Technical Report · Tue May 01 04:00:00 EDT 1990

OSTI ID:6066816

Tucker, W C; Mellman, G R; Henry, M

A +least-squares moment tensor inversion technique is applied to 10 presumed nuclear explosions from the French Polynesian test site at Mururoa. Our results indicate that tectonic release typically is quite low (with F 's ranging from 0.9 to .46) and makes little contribution to event moment. Assuming an oblique thrust orientation for the tectonic release mechanism, the delta m{sub b} between Mururoa and NTS is roughly .2 to .25 magnitude units. Finally, yield estimates generated from three different magnitude-yield relations are compared and found reasonably close to one another and to the one known yield value. A search technique is used to jointly invert multiple types of data for six Northern Novaya Zemlya presumed nuclear explosions to find the average tectonic release orientation (strike, slip, and dip). P waveform, SH polarity, and surface wave data were used in the inversion, but SV amplitude data had too much scatter to be included. The available data was insufficient to distinguish between a thrust and an oblique normal orientation. An improved distribution of stations recording SH polarities, more accurate SV data, and/or geologic knowledge of the source region could provide enough additional information to determine the orientation. The presence of multiple, substantially different orientations that fit waveform, surface wave, and polarity data suggests that more effort needs to be made to systematically search the model space for alternative solutions in studies involving both isotropic and double couple sources.

• Research Organization: Sierra Geophysics, Inc., Kirkland, WA (USA)
• OSTI ID: 6066816
• Report Number(s): AD-A-228258/0/XAB; SGI-R--90-143; CNN: F08606-87-C-0021; ARPA Order-4511
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450200* -- Military Technology
Weaponry
& National Defense-- Nuclear Explosions & Explosives
AMPLITUDES
CALCULATION METHODS
COMPARATIVE EVALUATIONS
DOCUMENT TYPES
ENERGY TRANSFER
EXPLOSIONS
NUCLEAR EXPLOSIONS
OCEANIA
ORIENTATION
PROGRESS REPORT
RECORDING SYSTEMS
SEISMIC SURFACE WAVES
SEISMIC WAVES
TECTONICS
YIELDS