Abstract:To quantitatively study the similarities and differences between ground and borehole background noise, we set up a seismograph on the ground of the Taole Seismic Station and use borehole seismograph for simultaneous observation. Firstly, sample data are selected to calculate the power spectral density of background noise. We analyze the power spectral density and average noise RMS values of different seismograph at different depths. The near and far earthquakes recorded by three seismographs are compared and analyzed. The results show that the near seismic waveform recorded by surface broadband, short period and underground short period seismograph are relatively clear and easy to identify seismic phases. Moreover, the teleseism waveform recorded by surface broadband and underground short period seismograph is relatively clear, while the teleseism waveform recorded by surface short period seismograph is poor, the waveform distortion is serious, and identifying the seismic phase is difficult. At the same time, in analysis and comparison of the recorded seismic source spectrum, we find that the near earthquakes recorded by the borehole seismograph are seriously disturbed in the frequency band of 7 to 12 Hz compared with the surface seismograph. The recorded teleseisms are seriously disturbed in the frequency band of 4 to 7 Hz, so they need to be handled carefully in seismic phase analysis.
TANG Hao,LI Hongting,BAI Xiaochuan et al. Comparative Study of Waveform Recorded by the Ground and Borehole Seismograph in Taole Seismic Station[J]. jgg, 2022, 42(7): 760-765.