Preliminary study on characteristics of earthquake precursor of earth resistivity anisotro

Preliminary study on characteristics of earthquake precursor of earth resistivity anisotropy degree in

East China

冯志生;杨建军;梅卫萍;耿杰;汪雪泉;刘义高

【期刊名称】《地震学报（英文版）》 【年(卷),期】2004(017)002

【摘要】@@ IntroductionrnThe degree of earth-resistivity anisotropy was

described

(MAO,

et

al,

1995,

1998)

as

follows:rnS=|1nn∑I=1(ρSNρEW)I|-1|×103 n=6(1)rnwhereρNS and ρEW are monthly mean values of earth resistivity in the direction of NS and EW, respectively, S is the half-year value. Equation (1) shows that if ρNS=ρEW, then S =0 and the electrical property of medium is isotropic; if ρNS≠ρEW, then S≠0 and the electrical property of medium is anisotropic. When S increases, the anisotropy of electrical property of medium is enhanced. Because the rightside of equation (1) is absolute value and the possibility ofρNS＞ρEW and ρNS＜ρEW can be different at different stations, the increase or decrease of S cannot reflect the relative changes between ρNS and ρEW. FENG, et al (2000) defined S as follows:

【总页数】7页(244-250)

【关键词】degree of earth-resistivity anisotropy;seismic anomaly;Fourier fitting;travel time curve