The aim of this paper is to present the results of an investigation of induced seismic events which occurred during mining in the coalfields of Plants Paskov and Staříč of the Paskov Mine which belong to the southern part of the Ostrava-Karviná coal mines. Some results obtained in the time period January 1992 - December 2002 have already been published, and therefore, are mentioned here only briefly. The paper is based on new results of seismological observations at the OKC, KLOK, STEB seismic stations operated by the Institute of Geonics AS CR and stations of the Green Gas DPB, a.s., Paskov. A total of 26 seismic events were monitored from January 2008 to February 2012, most of them were localized into the area under study. As for the energy span of individual events according to the energetic classification of the Geophysical Centre of the Green Gas DPB, a.s., Paskov, all seismic events in Table 1 were estimated within the limits E(J) <5.0 ×102 ÷ 2.0 × 104>., Karel Holub, Jana Rušajová and Josef Holečko., and Obsahuje bibliografii
We develop a robust and automatic determination of peak frequencies of direct wave arrivals from microseismic events using mirror image of the recorded signal. These peak frequencies can be then used to evaluate attenuation quality factor (Q). We propose to use procedure that consists of automatic determination of the peak frequencies in combination with matched filter to facilitate selection of suitable events. Using both natural and induced seismicity datasets, we show that matched filter detection along with automatic determination of the peak frequencies gives consistent values of quality factor when compared with manual processing. Proposed technique significantly reduces processing time making it a suitable tool in attenuation analysis of large datasets.