Accession Number:

AD0743072

Title:

Analysis of Teleseismic Data for the Nuclear Explosion Milrow

Descriptive Note:

Corporate Author:

TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA LAB

Personal Author(s):

Report Date:

1972-04-13

Pagination or Media Count:

148.0

Abstract:

MILROW, the second United States underground nuclear explosion on Amchitka Island, was an order of magnitude larger than LONG SHOT, the first test there. Magnitude-yield scaling between the two for both surface waves and body waves followed theoretical predictions well and agreed with Nevada Test Site NTS scaling. A computed location of MILROW using LONG SHOT travel-time anomalies was only 1.2 km in error horizontally and 11.8 km vertically, a substantial improvement over a location using no anomalies. The presence of direct shear waves and Love waves for MILROW can be attributed to causes other than tectonic strain release, such as mode conversion, crack formation, and structural features of the surrounding medium. The detection of Love waves from LONG SHOT and the MILROW cavity collapse were important results bearing on the determination of the shear-generating mechanism. All the common identification criteria were applied to MILROW and its collapse location and depth, Ms vs mb, spectral ratios, complexity, shear-wave excitation, and radiation patterns. MILROW appeared to be typical of explosions while, in contrast, the collapse was much like an earthquake. Author

Subject Categories:

  • Seismology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE