中强震前地磁谐波振幅比的趋势性变化特征初步研究  

PRELIMINARY STUDY ON THE CHARACTERISTICS OF LONG AND MEDIUM TERM VARIATION FOR THE AMPLITUDE RATIO OFGEOMAGNETIC HUMOROUS WAVE BEFORE MODERATE-STRONG EARTHQUAKES

作　　者：冯志生[1] 梅卫萍[1] 张秀霞[1] 庄明龙[1] 张晓勇[1] 

机构地区：[1]江苏省地震局,江苏南京210014

出　　处：《西北地震学报》2004年第1期50-56,共7页Northwestern Seismological Journal

基　　金：地震科学联合基金项目(101008)

摘　　要：应用最大似然谱分析技术,获得了上海佘山台和崇明台1982年至1999年的地磁三分量之间的短周期谐波振幅比。经初步分析发现,在中强地震前后谐波振幅比的趋势性异常表现为下降—转折—恢复的过程,持续时间为1～3年。同时变化还具有由长周期(深部)向短周期(浅部)迁移的特征。The amplitude ratios of short-period geomagnetic humorous wave among the three compnents from Sheshan and Chongming geomagnetic stations, Shanghai city, from 1982 to 1999 are obtained, with the technology of maximum-likelihood method (MLM).By preliminary analysis, the characteristics of long and medium term anomalous variation of the ratio in seismogenic process of moderate-strong earthquakes are declining,turning,then resuming,and the duration is about 1～3 years.Meanwhile the migration characteristics of the anomalous variation from long-period to short-period are found.

关 键 词：地磁异常 谐波 振幅比 

分 类 号：P315.75[天文地球—地震学]