Examining the Complex Relationship Between Seismic Moment and Explosive Yield
Session: Explosion Seismology Applications and Advances I
Type: Oral
Date: 4/19/2021
Presentation Time: 10:30 AM Pacific
Description:
We have calculated full (six-component) moment tensor solutions for dozens of chemical and nuclear explosions at the Nevada National Security Site (NNSS). The explosions are located through various locations at the test site (Pahute Mesa, Rainier Mesa, Yucca Flat, and Climax Stock) and in a variety of materials (granite, rhyolite, tuff, and alluvium). For all chemical explosions and a small subset of nuclear explosions, we have ground truth yield, depth, and shot point material while, for the other explosions, we have depth and shot point material, along with a yield range (Springer et al., 2002; DOE NV-209).
While seismic moment and explosive yield are obviously related, they are complicated by differences in material properties (including gas porosity), source depth (and scaled depth), and between chemical and nuclear explosions. Using this large database, we examine this complex relationship, first through simple regressions and progressing to more complicated approaches. One method is to model the source spectra through a combination of estimated seismic scalar moments and corner frequencies predicted through an explosion source model. Another approach is through the use of corner frequencies provided by coda-derived spectra. From these spectra, we can make estimates of the radiated seismic energy and relate those to explosive yield.
Understanding the complex relation between moment and yield would allow us to have a new method to estimate yield, independent of typical methods based on the teleseismic body wave magnitude mb, and applicable to new classes of explosions that cannot be observed teleseismically. We apply the methods to estimating the yield of the six recent declared DPRK nuclear explosions, and compare them to other estimates from teleseismic magnitudes, regional magnitudes, and regional envelopes.
Presenting Author: Michael E. Pasyanos
Student Presenter: No
Authors
Michael Pasyanos Presenting Author Corresponding Author pasyanos1@llnl.gov Lawrence Livermore National Laboratory |
Andrea Chiang chiang4@llnl.gov Lawrence Livermore National Laboratory |
Rengin Gök gok1@llnl.gov Lawrence Livermore National Laboratory |
|
|
|
|
|
|
Examining the Complex Relationship Between Seismic Moment and Explosive Yield
Category
Explosion Seismology Applications and Advances