The detectability of high frequency energy at teleseismic and regional distances, 1. Studies of radiation from high-explosive and nuclear cratering events, 2

Technical Report · Sun Mar 01 04:00:00 EST 1981

OSTI ID:6308082

Der, Z A; Blandford, R R

A survey of the literature on short period seismic studies showed that seismic waves of high frequency in the 3-10 Hz range can be observed regularly at both regional and teleseismic distances. These observations show that the low Q values proposed for the long period seismic waves cannot be valid in the short period band. The data indicate that, in the mantle, Q increases with frequency and may be as much as five times higher at 5-10 Hz than in the long period band. Even with the most conservative assumptions, the level of high frequency amplitudes in the teleseismic P waves exceeds that predicted with a constant t*p 1 sec by a factor of at least 100,000 at and beyond 5 Hz. The apparent Q beta of the lithosphere, which may be largely due to scattering by the small scale inhomogeneities in the crust, also shows an increase with frequency by as much as a factor of four within the 1-10 Hz band. This parameter controls the attenuation and the detectability of seismic waves at regional distances such as Pn, Pg, Su and Lg.

• Research Organization: Teledyne Geotech, Alexandria, VA (USA)
• OSTI ID: 6308082
• Report Number(s): N-8227888; AD-A-111855; SDAC-TR-81-6
• 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
ATTENUATION
CRATERING EXPLOSIONS
DETECTION
EARTH CRUST
EARTH MANTLE
EXPLOSIONS
GEOLOGICAL SURVEYS
NUCLEAR EXPLOSIONS
SCATTERING
SEISMIC DETECTION
SEISMIC WAVES
SURVEYS