Lg-Coda Methods Applied to Nevada Test Site Events: Spectral Peaking and Yield Estimation

K. R. Murphy; K. Mayeda; W. R. Walter

doi:10.1785/0120080046

Lg-Coda Methods Applied to Nevada Test Site Events: Spectral Peaking and Yield Estimation

Bulletin of the Seismological Society of America ◽

10.1785/0120080046 ◽

2009 ◽

Vol 99 (1) ◽

pp. 441-448 ◽

Cited By ~ 4

Author(s):

K. R. Murphy ◽

K. Mayeda ◽

W. R. Walter

Keyword(s):

Test Site ◽

Yield Estimation ◽

Nevada Test Site ◽

Lg Coda

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

Bulletin of the Seismological Society of America ◽

10.1785/bssa0830030851 ◽

1993 ◽

Vol 83 (3) ◽

pp. 851-861 ◽

Cited By ~ 2

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.

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Yield estimation using regional mb(Pn)

Bulletin of the Seismological Society of America ◽

10.1785/bssa0800030656 ◽

1990 ◽

Vol 80 (3) ◽

pp. 656-674 ◽

Cited By ~ 6

Author(s):

Eileen S. Vergino ◽

Richard W. Mensing

Keyword(s):

Large Population ◽

Test Site ◽

Yield Estimation ◽

Nevada Test Site ◽

Underground Nuclear Explosions ◽

Nuclear Explosions ◽

Threshold Test ◽

Using Data ◽

Yield Threshold ◽

Test Ban

Abstract Seismic yield estimation at regional distances will become increasingly important in monitoring a Low-Yield Threshold Test Ban (LYTTB). In order to investigate seismic yield estimation using regional data, we have examined regional mb(Pn) values for a large population of Nevada Test Site (NTS) underground nuclear explosions that occurred in widely varying geologic media with a range of yields from less than 1 kt to 300 kt. Magnitude-yield relationships were developed using data from a set of pre-1985 events (calibration set). To obtain an independent estimate of the uncertainty in estimating yields of events at NTS using mb(Pn) alone, the calibrated relationships were applied to a set of post-1984 events (prediction set). We found that the average uncertainty in the yield estimate, based on a weighted combination of the yield estimates from the four Livermore NTS Network (LNN) seismic stations, is about 1.8 (at the 2σ level). If data are available from all four LNN stations, the uncertainty is about 1.7 (at the 2σ level). By including a term for the gas-filled porosity of the rock near the working point in the magnitude-yield relationship, we were able to develop a single relationship valid for events both above and below the water table, as well as those in alluvium and tuff. We have found, however, systematic differences in the relationships for events in Yucca Flat, Pahute Mesa, and Rainier Mesa.

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