Aftershock observation in the focal region of the 2000 Western Tottori earthquake

The 2000 Western Tottori earthquake (MJMA7.3) occured in the western part of the Tottori prefecture in Japan on October 6, 2000. We observed aftershocks of this earthquake at three temporary stations of broadband seismograph close to the aftershock region from October 7 to December 1, 2000. The spectra of this aftershock show predominant frequencies of 0.3Hz at FKB and RFJ stations and 0.4Hz at KSD station. Those predominant frequencies may present seismic source process of this aftershock. Another predominant frequency was observed in 5Hz at KSD and RFJ stations. This predominant frequency may present a strong site-effect around these stations. We also performed an array observation by six temporary stations with short-period seismographs to study seismic wave propagation. We report the detail of observational conditions and show some waveforms of the aftershocks.