华北和华东地区地磁转换函数对地震的动态响应  

DYNAMIC RESPONSE OF GEOMAGNETIC TRANSFER FUNCTION TO EARTHQUAKES IN NORTH AND EAST CHINA

作　　者：曾小苹[1] 林云芳[1] 赵明[1] 汪江田[2] 林金狮 

机构地区：[1]国家地震局地球物理研究所,中国北京100081 [2]上海市地震局,中国上海200062 [3]山东省地震局,中国济南250021

出　　处：《地震》1994年第S1期50-57,共8页Earthquake

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.

关 键 词：地磁转换函数 电导率的横向非均匀性 频率响应 动态响应 

分 类 号：P315.7[天文地球—地震学]