The 16 August 1997 Novaya Zemlya Seismic Event as Viewed from GSN Stations KEV and KBS

Discrimination

Figure 8 - Vertical-component waveforms of regional events recorded at KEV. These events are representative of the data I used in my discrimination analysis. The locations of these events and all events used in this discrimination analysis are shown on Figure 1. Note that the Pn/Sn ratios of the explosions are about 3:1 while the Pn/Sn ratios of the other events are between 1:1 and 0.5:1.

Figure 9 - Example of Pn/Sn discrimination analysis for the 4-6 Hz band at KEV. (a) shows the uncorrected ratios-versus- mb trend, (b) shows the ratio-distance trend found using only earthquake ratios, and (c) shows the final discrimination plot.

  

Figure 10 - Distance-corrected ratio-versus-m discrimination plots for the 5-7 and 6-8 Hz bands. The label Mahalanobis refers to Mahalanobis Distance, a measure of separation between earthquake and explosion populations and the scatter within each population Note that the 16 August event moves into the earthquake population as frequency increases.

Table 2 - Events Used for Discrimination Analysis at KEV

  

Introduction | Background | Location | Discrimination | Summary