The Vértes Hills are interesting region in Hungary where small earthquakes with magnitude 2–3 exist among small quarry blasts in a noisy background. A seismological station PKSG (Gánt) works in the middle of Vértes Hills. The main purpose of this paper is to test the different discriminatory elements using the registrations of this single station.The diurnal discrimination of quarry blasts shows a peak time. My purpose is to focus onto these questionable earthquakes — happened in the peak time of the blasts — and be able to identify them.Every discriminant gave “1” if the event was considered to be a blast, and “0” if the event was considered to be an earthquake. The sum of these values shows the level of the separation. The classification of fifteen events was wrong. This is approximately 7 percentage of the dataset.It has been found that the spectral analysis and the correlation of spectra proved to be successful in the discrimination. One type of blast and five types of earthquakes are identified based on the correlation analysis of spectra of S-phases on the horizontal component. The result of the correlation analysis is that most of the spectrum of the blasts were very similar to each others. Correlation analysis has also showed that the big part of earthquakes could be classified into 5 groups. Earthquakes of each group concentrated on different places on the map. The maximum frequency and cepstrum analysis failed.
Arrowsmith S J, Arrowsmith M D, Hedlin A H, Stump B 2006:
Bull. Seism. Soc. Am.
, 96, 2368–2382.