Accession Number:

ADA123664

Title:

The Contribution of Two-Dimensional Source Effects to the Far-Field Seismic Signatures of Underground Nuclear Explosions

Descriptive Note:

Topical rept.

Corporate Author:

SYSTEMS SCIENCE AND SOFTWARE LA JOLLA CA

Report Date:

1980-07-01

Pagination or Media Count:

205.0

Abstract:

Two-dimensional calculations of underground explosions are able to include free surface interaction effects and the depth dependence of overburden pressure and material properties, as well as the complex constitutive models for geologic materials developed in one-dimensional spherically symmetric studies. Eleven axisymmetric calculations of explosions in granite are analyzed in this study to determine the two-dimensional effects on the far-field body and surface waves and the magnitude mb and Ms. Seven of these are hypothetical 150 KT explosions at depths from 159 to 1000 meters calculated by Applied Theory, Inc. ATI. These show depth effects that are different, though not strikingly so, from those calculated with one-dimensional source models. The other four calculations were done by Systems, Science and Software S-Cubed. The first was for a specific event PILEDRIVER, and the depth and yield were varied for the other three. the near- and far-field data for PILEDRIVER were matched rather well, except that the spallation was too large in the calculation.

Subject Categories:

  • Seismology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE