Finite Difference Cratering Support. Magnitude Determination of Cratering and Non-Cratering Nuclear Explosions
Final technical rept. on Task 1
TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS
Pagination or Media Count:
The ratio of the a phase and max phase of presumed Shagan River contained and cratering explosions are studied across the WWSSN network of short period stations. The amplitude of the a phase of the presumed cratering explosion of Jan 15, 1965 is found to e systematically larger in comparison to the max amplitude of this cratering explosion when compared to contained explosions in the vicinity of the cratering explosion. The log of the ratio of the amplitudes of the a and max phase, logPmaxPa, is on average smaller for the Jan 15, 1965 cratering explosion than for any of the contained explosions studied. Several methods wre used to study the systematics of the logPmaxPa value across the WWSSN network. The preferred method for determinig the average logPmaxPa was a maximum-likelihood method that includes the effects of data truncation of clipping for Pmax and non-detection of Pa. Assuming that the a phase amplitude of the cratering explosion is unaffected by the influence of the non-linear free surface interaction, the corrected magnitude for the cratering explosion is 0.17 to 0.27 magnitude units larger than its 5.88 WWSSN network magnitude. If the cratering explosion is credited with a yield of 125 KT then a 125 KT contained explosion in the Shagan River test site should produce a WWSSN network m sub b between 6.05 to 6.15.