An Analysis of the Seismic Source Characteristics of Explosions in Low-Coupling Dry Porous Media
Abstract
The dependence of seismic source coupling of underground nuclear explosions on the characteristics of the Q explosion source medium is an important consideration in any assessment of nuclear test monitoring capability. In particular, while experience has indicated that normal depth explosions in almost all hardrock and water saturated emplacement media (i.e., "good-coupling" media) are roughly consistent with a single nib/yield relation for any fixed tectonic source region, explosions in dry, porous media such as the dry tuffs and alluvium found above the water table at the Nevada Test Site (NTS), are typically observed to have m(b) values at a given yield that are lower than those in hardrock by about 0.50 +/- 0.25 magnitude units. With the exception of the complex cavity decoupling evasion scenario, which is not always feasible, explosions in such low-coupling media define the lower bound on the detection capability required to successfully monitor small, clandestine underground nuclear tests. However, at the present time, no fully reliable seismic source model is available to support quantitative analyses of broadband data recorded from such explosions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2009
- Accession Number
- ADA505385
Entities
People
- Brian W. Barker
- John R. Murphy
Organizations
- Leidos