华北和华东地区地磁转换函数对地震的动态响应
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摘要
地磁转换函数是利用地磁测深原理(GDS)推算的、表征观测点及其周围地区地下电性状态的一种无量纲参量,它是空间(测点)、周期(或频率)和地下深度(h)的函数。本文计算了我国华北和华东地区9个地磁台70年代以来的转换函数及其参量的动态变化,并考察了这种变化与各台附近发生的11个重要地震的时空变化关系,给出的主要结论是: (1)转换函数的模|A|或|B|的频率响应、|A|或|B|及其参量可作为地震的前兆参量。 (2)发现1989年10月18日和1991年3月26日两次山西大同地震前,转换函数的月变化率等值线出现类似震源机制的“四象限”现象,零等值线与未来地震的等震线相似。 在进行震例分析过程中,还进行了较为成功的预报地震实践。
The geomagnetic transfer function is a non-dimensional parameter which was inferred from the theory of geomagnetic deep sounding (GDS) and to express the characteristics of observing points and the subterranean state of the electro-conductivity in their surroundings. It is a function of space (observing point), time (t), period (T) and subterranean depth ( h) . The authors calculated the dynamic variations of the transfer functions since 70's from 9 geomagnetic observatories in the areas of North and East China and analyzed 11 important earthquakes occurred in their vicinity. The authors also conducted rether successful prediction in practice based on the following main results.
1) The module |A| or/ and |B| of the transfer functions and their frequency response could be regarded as a precursory parmater of an earthquake.
2) In the transfer functions of the observing points around the epicenters of the earthquake occurred on Oct. 18, 1989, the spatial distribution of some periodic
Δ|A| / Δt and/ or Δ|B| /Δt shows the "quadrant" phenomenon which appears to be analogous to the solution of earthquake source mechanism, and the space circled by the isoporics Δ|A|/Δt = 0 are also analogous to the isoseismic lines of the coming earthquakes.
The geomagnetic transfer function is a non-dimensional parameter which was inferred from the theory of geomagnetic deep sounding (GDS) and to express the characteristics of observing points and the subterranean state of the electro-conductivity in their surroundings. It is a function of space (observing point), time (t), period (T) and subterranean depth ( h) . The authors calculated the dynamic variations of the transfer functions since 70's from 9 geomagnetic observatories in the areas of North and East China and analyzed 11 important earthquakes occurred in their vicinity. The authors also conducted rether successful prediction in practice based on the following main results.
1) The module |A| or/ and |B| of the transfer functions and their frequency response could be regarded as a precursory parmater of an earthquake.
2) In the transfer functions of the observing points around the epicenters of the earthquake occurred on Oct. 18, 1989, the spatial distribution of some periodic
Δ|A| / Δt and/ or Δ|B| /Δt shows the "quadrant" phenomenon which appears to be analogous to the solution of earthquake source mechanism, and the space circled by the isoporics Δ|A|/Δt = 0 are also analogous to the isoseismic lines of the coming earthquakes.
引文
[1] Parkinson, W.D., Directions of Rapid Geomagnetic Fluctuations, J. Geophys., 2, 1959．
[2] Yanagthara, Y., Secular Variation of the Electrical Conductivity Anomaly in the Central Part of Japan, Mem. Kakioka Mag. Obs., 15, 1972．
[3] Yanagthara, Y. and Nagada, T., Time Change of Transfer Function in the Central Japan Anomaly of Conductivity with Special Reference to Earthquake Occurences, J. Geomag. Geoelectr., 23, 2, 1976．
[4] Shapiro, V.A. and Ivanov, N.A., Investigations of Secular Variation Anomalies in the Middle Ural Region, J. Geophys., 40, 1974．
[5] 徐文耀等,甘肃省东部地区短周期地磁变化异常及其与地震的关系,地球物理学报,21,3,1978年。
[6] 王琦,与1983年11月7日菏泽5． 9级地震可能有关的菏泽台地磁转换函数异常变化,地震学报,10,1,1988年。
[7] Sano, Y., Time Changes of Transfer Functions at Kakioka Ralated to Earthquake Occurrences(1) , Geovhy. Mag., 30, 2, 1980．
[8] 祁贵仲,“膨胀”磁效应,地球物理学报,21,1,1978年。
[9] Niblett, E.R. and Honkura, Y., Time-dependence of Electromagnetic Transfer Functions and Their Associatio with Tectonic Activity, Geophys, Surv., 4, 1980．
[10] 刘国栋、陈乐寿主编,大地电磁测深研究,地震出版社,1984年。
[11] 马杏垣主编,中国岩石圈动力学纲要,地震出版社,1987年。
[12] 曾小苹等,喀什台地磁短周期转换函数变化异常与其附近地震的关系,国家地震局科技监测司主编,地磁地电专辑,学术书刊出版社,1990年。
[13] 曾小苹等,一种揭示孕震过程的地磁前兆新方法-地磁短周期法,国家地震局地球物理所主编,地震预报研究论文集,地震出版社,1992年。
[14] Lin, Y.F. and Zeng, X.P., The Response of Anomalous Short Period Geomagnetic Variations to Moderate-Strong Earthquakes in China, J. Earthq. Prediction Res., 1, 1992．
[15] Parkinson, W,D,, Introduction to Geomagnetism, Scolish Academic Press, 1982．
[16] ~~3, 1991．
[2] Yanagthara, Y., Secular Variation of the Electrical Conductivity Anomaly in the Central Part of Japan, Mem. Kakioka Mag. Obs., 15, 1972．
[3] Yanagthara, Y. and Nagada, T., Time Change of Transfer Function in the Central Japan Anomaly of Conductivity with Special Reference to Earthquake Occurences, J. Geomag. Geoelectr., 23, 2, 1976．
[4] Shapiro, V.A. and Ivanov, N.A., Investigations of Secular Variation Anomalies in the Middle Ural Region, J. Geophys., 40, 1974．
[5] 徐文耀等,甘肃省东部地区短周期地磁变化异常及其与地震的关系,地球物理学报,21,3,1978年。
[6] 王琦,与1983年11月7日菏泽5． 9级地震可能有关的菏泽台地磁转换函数异常变化,地震学报,10,1,1988年。
[7] Sano, Y., Time Changes of Transfer Functions at Kakioka Ralated to Earthquake Occurrences(1) , Geovhy. Mag., 30, 2, 1980．
[8] 祁贵仲,“膨胀”磁效应,地球物理学报,21,1,1978年。
[9] Niblett, E.R. and Honkura, Y., Time-dependence of Electromagnetic Transfer Functions and Their Associatio with Tectonic Activity, Geophys, Surv., 4, 1980．
[10] 刘国栋、陈乐寿主编,大地电磁测深研究,地震出版社,1984年。
[11] 马杏垣主编,中国岩石圈动力学纲要,地震出版社,1987年。
[12] 曾小苹等,喀什台地磁短周期转换函数变化异常与其附近地震的关系,国家地震局科技监测司主编,地磁地电专辑,学术书刊出版社,1990年。
[13] 曾小苹等,一种揭示孕震过程的地磁前兆新方法-地磁短周期法,国家地震局地球物理所主编,地震预报研究论文集,地震出版社,1992年。
[14] Lin, Y.F. and Zeng, X.P., The Response of Anomalous Short Period Geomagnetic Variations to Moderate-Strong Earthquakes in China, J. Earthq. Prediction Res., 1, 1992．
[15] Parkinson, W,D,, Introduction to Geomagnetism, Scolish Academic Press, 1982．
[16] ~~3, 1991．
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