乌鲁木齐重力潮汐研究与震兆异常
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摘要
利用Ｖｅｎｅｄｉｋｏｖ调和分析法分析了乌鲁木齐ＧＳ－１５－２１６重力仪１９９０～１９９３年的潮汐记录，得到了该地区的重力潮汐参量：δｏ１＝１．１５８２６±０．０００４９，Δｏ１＝０．１５±０．０２，δＭ２＝１．１６１０８±０．０００２２，ΔＭ２＝－０．３２±０．０１。主波Ｍ２和Ｏ１的结果与１９８０年中比协作时ＧＥＯ－０８４的观测结果一致，与Ｍｏｌｏｄｅｎｓｋｙ模型１值符合很好。不同时段得到的δ值和Δ值内符合精度高，表明乌鲁木齐地区重力场稳定，重力仪性能稳定，观测资料可用于检验地球模型、研究地球深部构造以及震源物理场。分析了和静东北两次５．２级地震前δＭ２值的短期前兆异常，确认从目前的重力潮汐观测中可以分辨出变化量大于１％的δ因子震兆异常．
According to Venedikov's harmonic analyzing method,the authors made analysis on the tidal data of Urumqi district during 1900￣1993 recorded by type GS-15-216 gravity meter.Gravity tidal parameters in Urumqi district were gained, finding that the values of main waves M2 and O1 not only consistent with the results from GEO-084 gravity meter in 1990 in Belgium--China cooperation,but also coincident with the ones from Molodensky Model I.As a high internal coincidence precision has been got both from value δ and from value Δψ in different time intervals,it shows gravity field is stable,and gravity meter's performance is good in Urumqi district. The ordinary observing data can be used to study earth model,deep structure and focal physical field. Using these data,the authors analyzed the short -term precursory anomaly on value δM2 occurred before two earthquakes (Ms 5. 2) in northeast of Hejing,which proves seismic precursory anomaly that varied less than 1% of factor δ can be identified by gravity tidal data.
According to Venedikov's harmonic analyzing method,the authors made analysis on the tidal data of Urumqi district during 1900￣1993 recorded by type GS-15-216 gravity meter.Gravity tidal parameters in Urumqi district were gained, finding that the values of main waves M2 and O1 not only consistent with the results from GEO-084 gravity meter in 1990 in Belgium--China cooperation,but also coincident with the ones from Molodensky Model I.As a high internal coincidence precision has been got both from value δ and from value Δψ in different time intervals,it shows gravity field is stable,and gravity meter's performance is good in Urumqi district. The ordinary observing data can be used to study earth model,deep structure and focal physical field. Using these data,the authors analyzed the short -term precursory anomaly on value δM2 occurred before two earthquakes (Ms 5. 2) in northeast of Hejing,which proves seismic precursory anomaly that varied less than 1% of factor δ can be identified by gravity tidal data.
引文
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