Accession Number:

ADB110040

Title:

Estimating Explosion and Tectonic Release Source Parameters of Underground Nuclear Explosions from Rayleigh and Love Wave Observations. Part 1

Descriptive Note:

Final technical rept. Jan 1985-Jan 1986

Corporate Author:

SIERRA GEOPHYSICS INC KIRKLAND WA

Personal Author(s):

Report Date:

1986-07-01

Pagination or Media Count:

80.0

Abstract:

The long period approx 20s Rayleigh and Love waves for 37 events at Shagan River and 47 events at NTS are inverted for source parameters using the best available information on propagation for each source receiver path and on excitation for each source region. At these periods, a three parameter source model is sufficient to describe the Rayleigh and Love wave amplitude and phase radiation patterns. However, the scatter in the source amplitudes dominates the radiation patterns of the surface waves, and additional station correction factors are necessary. These corrections are derived by simultaneously inverting many events from each test site for both the source parameters and station corrections. The inclusion of both Love and Rayleigh waves for events with a wide range of relative Love to Rayleigh wave excitation reduces possible bias in the station corrections. This feature is important because no events at either test site are free from tectonic release effects. The three source parameters do not constrain the size of the explosion source and further interpretation is necessary. At Shagan River, the tectonic release mechanism must include a substantial thrust-faulting component at NTS, a strike slip fault model for the tectonic release is appropriate. With the thrust fault model, the Rayleigh waves from the typical median event at Shagan River are reduced in amplitude by the effects of tectonic release by 0.3. The explosion moments of the largest events at Shagan River are slightly higher than the largest events analyzed from NTS.

Subject Categories:

  • Seismic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE