Recent Methodological Developments in Magnitude Determination and Yield Estimation with Applications to Semipalatinsk Explosions
Abstract
An improved magnitude determination procedure is presented to account for the empirical near-source focusing/defocusing effects. This scheme provides more stable m sub b measurements with a reduction in the fluctuational variation by a factor of up to 3. The events which do not show significant improvement could have been detonated in environments with different focusing patterns. The scatter in the network-averaged m sub b based on the new scheme versus log(yield) is smaller that that for conventional GLM or LSMF m sub b. Our major developments in the seismic yield estimation methodology include: (1) a refined m sub b determination scheme ; (2) a regression algorithm 'MLE-CY' which utilizes the bounded (i.e., censored) yields in the m sub b-yield calibration based on the maximum-likelihood approach; and (3) a regression algorithm 'DWLSQ' which permits both variables to be imprecise due to either rounding or standard measurement errors, thus extending the ordinary weighted least-squares regression. These new techniques are fully tested with recently published Soviet yields of historical Semipalatinsk explosions and the WWSSN m sub b database established at Geotech. The results all appear to be very encouraging in improving our remote monitoring capability.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 16, 1991
- Accession Number
- ADA244503
Entities
People
- Robert A. Wagner
- Rong-song Jih