Modeling near-field and teleseismic observations from the Amchitka test site

Journal Article · Sun Jun 10 04:00:00 EDT 1984 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB089iB06p04373· OSTI ID:6555792

Burdick, L J; Wallace, T; Lay, T

During the Amchitka testing program, recordings were made of the near-field ground velocity for events MILROW and CANNIKIN. These records exhibited a P arrival, a feature associated with near-field pP and a developing Rayleigh wave. In this investigation, simple models were found which match the complete seismograms. They simultaneously predict the amplitude, wave shape, timing, and periodicity of both the body waves and the surface waves. Models for both the Amchitka crustal structure and the source time functions were developed. The crustal model is similar to previous models in its averge properties, so travel time constraints are still satisfied. Small modifications have been made to match the waveform data. The events on Amchitka can apparently be represented as isotropic point sources with the types of simple source time histories predicted by classical yield scaling laws. A source model for event LONGSHOT was developed on the basis of the yield scaling laws since no near-field records are available for it. The source models were tested by comparing the teleseismic body waveforms they predict with observations. Short-period P waves, long-period P waves, and long-period pS waves were considered. The short-period P waves provided the best constraint. To match them, it was necessary both to develop a model for teleseimic pP since it arrives later than the near-field model would predict and to estimate the average value of t*. The MILROW and CANNIKIN teleseismic short-period P waves indicate that the average effective t/sub ..cap alpha../( for teleseismic ray paths from Amchitka is 0.9 s. The scatter about this value, however, is very substantial.

• Research Organization: Woodward-Clyde Consultants
• OSTI ID: 6555792
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 89:B6; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450201* -- Military Technology
Weaponry
& National Defense-- Nuclear Explosions & Explosives-- Containment
CANNIKIN EVENT
EARTH CRUST
EXPLOSIONS
GEOLOGIC MODELS
GROMMET OPERATION
LONG SHOT EVENT
MANDREL OPERATION
MILROW EVENT
NUCLEAR EXPLOSIONS
RAYLEIGH WAVES
SEISMIC P WAVES
SEISMIC SURFACE WAVES
SEISMIC WAVES
UNDERGROUND EXPLOSIONS
VELA PROJECT
WAVE FORMS
WAVE PROPAGATION