Downhole Instrument Orientations and Near Surface Q Analysis from the SMART2 Array Data

由SMART2陣列資料分析井下地震儀之方位及近地表之Q值

彭瀚毅(Han-Yih Peng) ； 溫國樑(Kuo-Liang Wen)

《Terrestrial, Atmospheric and Oceanic Sciences》 4卷4期 (1993/12) Pp. 367-380

並列摘要

Installation of the SMART2 downhole array in Da-Han Industrial School was completed in May 1992. This array contains one free surface station and three downhole accelerometers down to 200 m depth. Thirteen events recorded by this downhole array are used to study the orientations of the downhole instruments by cross-correlation method. The results show the longitudinal direction of the instruments at 50 m, 100 m, and 200 m depths of downhole accelerometers are N3°E, N91°E, and N75°E, respectively. Thenear surface Q value is calculated by using the records of three events. The result of Q(f)=9.55 f^(1.06) was obtained from the smoothed power spectrum ratios. The surface ground motions of two events are simulated from the observed downhole records and Q value we obtained by using the Haskell method. The results confirm the downhole instrument orientations and near surface Q value that we derived in this study.