Accession Number : ADA323699

Title :   Investigations of the Seismic Discrimination of Rockbursts.

Descriptive Note : Final rept. Jul 94-Jul 96,

Corporate Author : MAXWELL TECHNOLOGIES INC SAN DIEGO CA

Personal Author(s) : Bennett, Theron J. ; Marshall, Margaret E. ; Barker, Brian W. ; McLaughlin, Keith L. ; Murphy, John R.

PDF Url : ADA323699

Report Date : JUL 1996

Pagination or Media Count : 69

Abstract : Our principal objective in this research has been to identify and test regional discrimination measures which can help facilitate the identification of the numerous rockbursts which are likely to be encountered in CTBT monitoring. We have reviewed characteristics of rockburst mechanisms and their seismic signals for a variety of different mining, tectonic, and propagation environments; and we have discovered several problem areas for rockburst discrimination. Our recent investigations have been directed primarily at three source areas where rockbursts occur frequently: (1) the South African gold-mining region, (2) coal-mining and copper-mining regions in Poland, and (3) coal mines in eastern Kentucky and western Virginia. For each of these areas, we have collected and analyzed waveform data from a significant sample of rockburst events recorded at high quality digital seismic stations which would be critical to regional monitoring under a CTBT. The analyses have focused on assessing the value of Lg/P ratios as a function of frequency for distinguishing rockbursts from underground nuclear explosion tests. The Lg/P ratios for the rockbursts in each source area tend to be larger over a broad range of frequencies, and this appears to provide one of the most promising discriminants.

Descriptors :   *UNDERGROUND EXPLOSIONS, *SEISMIC DISCRIMINATION, ROCK MECHANICS, SEISMIC WAVES.

Subject Categories : Seismic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE