【摘要】 张江深井综合地震观测站是上海市规则建设的深井地震综合观测系统中首先建成并投入运行的站点,深井中安装了地磁仪、应变仪、倾斜仪、测震仪、孔隙压仪、地温仪、水温仪和水位仪,地表还安装了强震仪和GPS,总计十种测项,同时地表还配备气压计和气温计等辅助观测手段。张江台在2006年就建立了地表台,本文将地表台和新建的深井台数据进行了分析对比,从而得出土层背景噪声的干扰情况;同时参照上海台网其他深井的资料分析综合深井系统对测震单分项系统是否有干扰。结果显示,深井台的背景噪声RMS数值比地表台小个数量级,可以更精确的记录到地脉动数据;深井台的有效动态范围比地表台超出30%;深井台不仅在低频,在高频段25Hz附近也有噪声影响;深井台比地表台受环境噪声影响要小很多,特别是在低频段优势更明显。同时,对比张江综合深井台的地噪声、动态范围和上海台网其他深井台资料,认为综合深井测震分项数据未受到整体综合系统的噪音影响。更多还原

【Abstract】 Twenty-seven deep seismic observation stations are planned for construction in the administrative area of Shanghai to provide a comprehensive observation system of deep earthquakes,and two deep seismic observation stations will be constructed in Zhangjiang,Pudong district,and the Yangtze River farm,Chongming district,in accordance with China’s Eleventh Five-Year Plan.The deep well station in Zhangjiang has been completed and has passed the acceptance stage.Ten test items have been installed including a magnetometer;strain gauge;inclinometer;seismometers;pore pressure,temperature,and water temperature instruments;a water meter installation site in a deep well,a surface-installed strong motion seismograph,and a global positioning system(GPS).In addition,the surface is equipped with a pressure gauge,a temperature gauge,and other auxiliary observation tools.In this study,the micro-tremor and dynamic range data of the Zhangjiang surface station and deep well station data are compared and analyzed systematically.We obtained the following preliminary results: The root mean square(RMS) value of background noise in the deep well is smaller in orders of magnitude than that at the surface station.It can accurately record micro-tremors because of only slight disturbances by the external environment.The seismic signals of deep well observation are the most accurate.The dynamic range of measurement stations effectively reflects the instrument’s performance indicators to determine the background environment interference level recorded by the maximum dynamic range of the seismic signal.Due to the superposition station environment noise and seismic signal,the instrument is not up to the dynamic range of design and can only achieve an effective dynamic range of measurement.The effective dynamic range of the deep well station exceeds 30% of that of surface stations;therefore,it can produce a broader range of micro-tremors.Range surface frequency is within 0.3~2.5;the deep well station has low-frequency noise and nearly high-frequency at 25 Hz.A comparison of deep bench surface stations reveals that environment noise is much smaller,particularly in the low-frequency range.Moreover,with reference to analysis of data from the Shanghai telemetry seismic network of various types of base background noise,the dynamic range of noise at the Zhangjiang comprehensive deep well and those of the Shanghai network deep wells are consistent.Therefore,comprehensive visible data for the deep seismic section is unaffected by the noise integrated system.With the accelerated process of city development,environmental noise will increase;therefore,the deep well seismometer observation method is more reliable than surface seismometer observation.Completed construction of the seismic section of the deep borehole project can provide greater precision and better quality of observation data to further improve the earthquake monitoring capacity of Shanghai.更多还原