• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.13-19
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• 2003

Discriminant method using seismic signal was studied for discrimination of surface explosion. By means of the seismic spectral characteristics, multi-variate discriminant analysis was performed. Four single discriminant techniques - Pg/Lg, Lg1/Lg2, Pg1/Pg2, and Rg/Lg - based on seismic source theory were applied to explosion and earthquake training data sets. The Pg/Lg discriminant technique was most effective among the four techniques. Nevertheless, it could not perfectly discriminate the samples of the training data sets. In this study, a compound linear discriminant analysis was defined by using common characteristics of the training data sets for the single discriminants. The compound linear discriminant analysis was used for the single discriminant as an independent variable. From this analysis, all the samples of the training data sets were correctly discriminated, and the probability of misclassification was lowered to 0.7％.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.98-112
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• 2000

Discrimination between natural earthquakes and man-made explosions is very essential but critical matter in Seismology. In the CTBT Monitoring business, this is very crucial issue and sometimes could occur the international conflict. In this study, we analyzed seismic and infrasound data from Chulwon Seismo-Acoustic Array and would like to introduce routine data processing procedures at the Korea Institute of Geology, Mining and Materials(KIGAM) to discriminate the earthquakes and artificial explosions. We found analyzing acoustic data together with seismic data is very effective way to identify and discriminate man made explosion from natural earthquake. Recent earthquakes in and around the Korean Peninsula are concentrated in a narrow zone with N60-70$^{\circ}$W in southern Korea, and Pyungan and Hwanghae Province in northern Korea. The mechanism of 14 larger earthquakes in and around the Korean Peninsula since 1936 show predominant strike-slip faulting together with minor thrust component. This indicates horizontal compression is dominant in and around the Korean Peninsula.

• Journal of the Korean Geophysical Society
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• v.3 no.1
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• pp.25-36
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• 2000

3-D Spectrograms for 22 events are drawn to discern about whether those are earthquakes or explosions. Generally, in case of explosions relative to the case of earthquakes, amplitude of P phase is more dominantly shown. According to the results on logarithm of spectral ratio of P (Pn, Pg)/Lg after removing free-surface effects from 3-D (U-D, N-S, E-W) seismogram, $-1.2{\sim}-0.9$ is shown for earthquakes and $-0.7{\sim}-0.1$ if shown for explosions. This result is consistent with previous researches (Kim Park, 1997) that -0.6 of spectral ratio between P and Lg after taking logarithm may be the criterion for the discrimination between earthquakes and explosions in Korea. In addition, Complexity is applied to two events as another discrimination method. The value of Complexity of explosion is much smaller than that of earthquake. This may be due to well-developed P-wave in explosion compared to that in earthquake. This result is in accordance with that of 3-D Spectrogram.