Magnitude: Yield for Nuclear Explosions in Granite at the Nevada Test Site and Algeria: Joint Determination with Station Effects and with Data Containing Clipped and Low-Amplitude Signals

1982 ◽  
Author(s):  
Robert R. Blandford ◽  
R. H. Shumway
Keyword(s):  
Test Site ◽  
Nevada Test Site ◽  
Nuclear Explosions ◽  
Joint Determination ◽  
Low Amplitude

Lg magnitudes and yield estimates for underground Novaya Zemlya nuclear explosions

1988 ◽  
Vol 78 (2) ◽  
pp. 873-884
Author(s):  
Otto W. Nuttli
Keyword(s):  
Large Range ◽  
Test Site ◽  
Nevada Test Site ◽  
P Values ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Novaya Zemlya ◽  
Short Period ◽  
Lg Wave ◽  
Range Of Values

Abstract Lg-wave amplitudes of 30 Novaya Zemlya underground nuclear explosions, as recorded by short-period seismographs in Denmark, Finland, Germany, Norway, Spitsbergen, and Sweden, are used to determine mb(Lg) values. Assuming that the mb(Lg) versus explosion yield relation derived from Nevada Test Site data applies to all continental areas, the yields of the explosions are estimated. They cover a large range of values, from 2.5 to 4900 kt. The largest explosion since April 1976 had an estimated yield of 145 kt. The mb(Lg) values, when subtracted from the mb(P) values, can be used to estimate the mb(P) bias between two test sites. In this way, the mb(P) bias between Novaya Zemlya and the Nevada Test Site is estimated to be 0.20 magnitude units.

mb(LgCoda): A stable single station estimator of magnitude

1993 ◽  
Vol 83 (3) ◽  
pp. 851-861 ◽  
Author(s):  
Kevin Mayeda
Keyword(s):  
Water Table ◽  
Source Region ◽  
Test Site ◽  
Strongly Correlated ◽  
Nevada Test Site ◽  
Nuclear Explosions ◽  
Empirical Relations ◽  
Single Station ◽  
Lg Coda ◽  
Lateral Variations

Abstract Stable single-station estimates of magnitude have been made using the 1-Hz Lg coda envelope of regionally recorded nuclear explosions from the Nevada Test Site (NTS). After empirical relations describing the Lg coda envelope were found for each NTS-station path, single station magnitudes based on the Lg coda envelope were made with precision in the range of 0.03 to 0.04 magnitude units, whereas magnitudes based on third peak Lg amplitude, rms Lg amplitude, and Pn amplitude had scatter on the order of 0.15 to 0.2 magnitude units, generally five times larger than the coda scatter. Despite the high station correlations, the magnitude-yield residuals for events above the water table using the network average mb(LgCoda) were only marginally better than the other magnitude estimates, roughly 10% smaller. Magnitude-yield residual for events above the water table between mb(LgCoda) and mb(Lg) are strongly correlated suggesting that the source region properties, such as gas porosity, affect both magnitudes. Using only a single station, the standard deviation for magnitude-yield residuals using mb(LgCoda) were roughly 25% smaller than those derived from mb(Lg) or mb(Pn). These results show that the method is ideally suited to monitoring efforts in sparsely instrumented regions where little is known about the lateral variations of medium properties.

Seismic magnitudes of underground nuclear explosions

1973 ◽  
Vol 63 (1) ◽  
pp. 105-131 ◽  
Author(s):  
P. W. Basham ◽  
R. B. Horner
Keyword(s):  
Computational Procedure ◽  
Test Site ◽  
P Wave ◽  
Nevada Test Site ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Novaya Zemlya ◽  
Yield Information ◽  
Short Period ◽  
Propagation Effects

abstract Using an Ms computational procedure that minimizes path-propagation effects, and with Ms values found to be empirically independent of test site and detonation medium among consolidated rock explosions, available yield information is employed to illustrate that the seismic scaling of explosions in realistic detonation environments produces teleseismic Rayleigh-wave displacements proportional to the 1.2-power of yield over the range from low yields to greater than three megatons. Ms values independent of network, path, and site can be employed to estimate unknown yields at uncalibrated test sites to within average errors judged to be about 20 per cent. P-wave magnitudes, in the form of a calibrated teleseismic measure of short-period P-wave displacements, show a theoretically supported dependence of displacement on the 1.1-power of yield over the range from 6 kt to 1 mt. Studied explosions separate into two categories: the Nevada Test Site granite explosions, LONG SHOT, the Sahara February 1965 explosion and (by empirical inference) Novaya Zemlya and Eastern Kazakh explosions exhibit P-wave displacements about a factor of 3 greater than explosions of the same yield in tuff, rhyolite, and shale. P-wave magnitudes of explosions are subject to such a diversity of source, propagation, and measurement phenomena that any estimation of unknown yields without a closely controlled site and network calibration can be subject to large errors.

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